Onan NHE, 6.3 NHEL, NHEL, 6.5 NHE Service Manual

Service

Redistribution or publication of this document by any means, is strictly prohibited.

Manual

GenSets

RV

Electric Generating Set

(Spec

940-0502

7-87

Printed

In

A-C)

U.S.A.

Safety

Redistribution or publication of this document by any means, is strictly prohibited.

Precautions

Boforo oparatlng Manual

and

rffldent oporation can

pmpeq

caused y failure to follow fundamental rdes and precautions.

The

to

sonnel,

ards

oporatod

following symbols, found throughout this manual, alert

potentiall dangerousconditionsto theqmator,service per-

or

x

which

tho

become

e

equipment.

77th

will

result

generator

familiar

and maintained. Many accidents are

sjmboi warns

In

with

it

ba

achleved

sevete

set,

read the Operator's

and

the

ui ment. Safe

oqy

1

the

of

immediate haz-

personal Injq or

unit

you

death.

iMWAANlNGI~fssym~lrefers

practrce which

or

death.

IricAunoNj

practice

uct

FUEL

personal

whlcb

or

propew

AND

injury

DO

NOT

with

hot

DO

NOTSMOKE

erator

set

hnl

lines must

Fuolconnoction

prowdllexjble,~uCtiveline.

iq

on

floxible

bnttlr.

Bo

sure

-LINE

NlED

BY

fin

luy

UECTRICALSPARKS,

or

oxp~on,

M

duth.

Do

not

tk

Do

not

M

mpartmont

rkctrical

Koep

Phco

a

Pnawinmfer

ll

okchical

pubnont

sqamtod

by

pusing

DO

NOT

t.ri.s

omit

dod

by

EXHAUST

Now

sloop in

kvohide

can

result

Thlssymbolrefers

can

msult

d8mge.

FUMES

fill

engine

dl

AND

physical

qning,

SMOKE

okctrical

GASES

ARE

can

fuel

or

fuel

lines

fuel

Whm

electrical

electrid

openings.

FLAMMABLE.

result from improper practices.

tanks

while

or

exhaust

OR

USE AN

tank

be

dquatrly

at

tlw

eMne

as

copper

supplh

LPG

and

haw

FUEL

w~ch

an

lnthlllng

wiring

lines

fuel lines

bonier

botwaen

to

and

possible.

and

furl

fines

mud

make

by

rumingthem

oach

lino

while

a

highly

arcing

ARE

the

vshido

is

equipped

certain

through

soruicing

oxplaSiv6

or

DEADLY

with

to a hazard orunsafe

in severe personal Injuty

to

a

in personal

engine

is

is a potential

MAY

muR

fuel

as

through

a

by smoking.

an

running. Fuel

OPEN

FLAMEnearthegen-

secund

should

be

Donotusecopperpip-

will

work

harden

a

positivo

BE

ACClDEMALLY

rwmtfngthr

In

mvw.

tho

genorator

lines.

fuel

lines through

far

apart

fuel

pass

through

that

they

indii

separate

batteries.

hyiimgen

the

generator

operating

hazard

Fire. explosion, and

lines

gas

fnjuty

fire

hazard.

and

free

made

shutoff

as

possible.

and

the

are

piece

Lead

that

set

carbon

or

unsafe

orpmd-

cork~ct

of

leaks.

with

an

and

become

valve.

hazud

pmona,

Mt:

the

same

elsctn'cal

mo

com-

physically

channels,

of

tubing.

aad

bat-

can

be

Nnning un-

monoxide

ap-

IG

of

In-

or

g-

dasctor.

e

Provide

an

adeqde

charged

th,

am

heat

e

Be

MOVING

JURY

e

Before starting work on

ies.

gases. In

maintenance

securo

and

a

compartment.

sure

the

unit is

PARTS

OR

DEATH

This

will

exhaust

Jz de.

not

warped.

well

CAN

prevent acadental arcing.

system

to

exhaust

ventilated.

CAUSE

the

system daily for leaks

Ensure that

Do

mi

use

SEVERE

generator set, disconnect batter-

properly

expel dis-

per

exhaust

manifolds

exhaust gases to

PERSONAL

IN-

0

Keep

your hands away from moving parts.

Is

0

Make sure that fasteners on Tighten supports and clamps. keep guards in position over

fans, drive belts, etc.

0

Do

not

wear

loose

sets.

erator in moving parts. Jewelry and cause shock

e

If

adjustment must

treme

caution

ELECTRICAL

INJURY

'GENERAL

OR

DEATH

Disconnect starb'ng battery before

or

shields

tive

metal wear dampclothing faces to

Use

nents.

Follow

installations

Tag

DO

ANY

agescanflowfrom creates

Con&

nuin

-rgsncyponnr-.

~ave

edy

ABC

sdt

guisher

Hot

juty.

is

running.

pnsue.

Benzene

Wkdbysane~eandf~eralagenciesas~ng~r

or

gasoline,

tact

Used

ed

When

gest.

Remove

mulated

damage,

DO

as

propane cylinders, etc. A fire set operation (cooling, versely affected. Keepthe compartment

Do

fatigued. or

the

touching

mats placed on dry woad platforms

or

concrete when around

be

extreme

High voltages can

all state

open switches

NOT CONNECT GENERATOR

BUILDING

a

potential

only through

switch

SAFl3Y

afire oxtinguisimr

and

become

by the

the

Id

for

coolants

DONOTo~aradiatorpre~ruecepwtriktheengine

and

reproduCtive

take

gasdine.

engine oils have

agencies

checkjng or changing

breathe the fumes,

all

grease and oil

which presents a

NOTstore

oil

or gas

not work on

operation

clothing

Loose

clothing and jewelry can become caught

or

burning.

be

made whilethe

around hot manifolds, moving

SHOCK

CAN CAUSE

electrical

(particu1arlywetshoes)orallowskinsur-

damp when handling

caution

and

local

perform4

to

ELECTRICAL

thegeneratorsotintotheutilityline.

for

an

is

0p.n.

PRECAUTDNS

familiar

NFPA

are

fire

department

various

applications.

under

prossure

Stop

the

engine

bad,

found

toxicity.

care

not

as

causing

unnecessary

anything

cans,

oily rags, chains, wooden

this

after

equipment

consuming any alcohol or

of

equipment

the

generator set are secure.

or

jewelry while working on gen-

can

short

out

electrical

unit

is running,

SEVERE

equipment

removing

electrical

Use

over

equipment.

electrid

when working on

cause

injury or death.

ekctrical

by

a

qualied

avoid

accidental

SYSTEM.

electrocution

apprwed device

Consult an

new.

appropriate for all appliations.

When

to

been

can

in

~aintainoxtinguistmr prOp

with

its

use.

for

the

can

cause

and

carefdly

in

mo

gasoline,

checking,

ingest,

breathe

identified

cancer

engine

or

contact

grease

and

cause

potential

the

generator

electrical

des.

Havo

licensed

closure.

SET

oc

pmporty damage.

and

electriaan

Extbrguishers

correct

sovom

bbd

haw

draining or

tha

by

801110

or

reproductivb

oil,

take

used

oil.

oil

from.th.

overheating

fire

hazard.

compartment

blocks,

could

result

noise

and

when

or

vibration)

floor

mentaliy

drug

unsafe.

contacts

parts,

etc.

PERSONAL

protective

rubber

floors

that

equipment.

compo-

dl

electrical

electrician.

DIRECTLY

Hazard-

after

building

m

regard

type

of

porsolwl

th.

systom

boon

adding

fumes,

or

st&

toxicity.

cam

not

unit.

and

engine

portable

tho

generator

may

be

doan

and dry.

or

physically

that makes

use

ex-

insula-

are

Do

not

TO

vdt-

This

to

rated

Con-

extin-

in-

idon-

con-

or

fad-

to

in-

Accu-

such

ad-

RV-9

,

I

1.

.

Redistribution or publication of this document by any means, is strictly prohibited.

Supplement

Date:

8-85

Insert

with

-

Ti

NHE/NHEL Service Manual

Number:

This supplement includes latest starter repair informa-

tion for models NHE/NHEL

RV

gensets.

940-0502

940-1039

FIGURE

1.

ELECTRIC STARTER

The following procedures cover the disassembly and

of

testing

electric starter.

Disassembly

Use the following procedure to remove and disassemble the starter.

1.

Disconnect the generator set negative cable from the set starting battery.

2. Disconnect the generator set positive cable from the starter lug terminal.

SUPPORT

A

USE

HAVE

"LEG"

~__

RETAINER & SUPPORT WHEN

DRIVING

PLASTIC

RETAINER

VISE

OR

SOUD

SURFACE

CARE

SPRING

BETWEEN

~

OUT

WITH

OTHER

NOT

TO

RETURN

THE

PLASTIC

ROLL

PIN.

(-)

(+)

battery battery

191-1667

STARTER

=16M

3. Remove the starter mounting screws and then carefully disengage the starter from the stator housing.

4.

Remove starter through-bolts and carefully separate the brush end cap housing and armature assembly.

5.

Use a

1

/8

to 5/32 inch nail set to remove roll pin. Remove return spring, gear and clutch assembly as required. When reassembling always usea new roll

5/32"

pin. See Figure

lo 118

NAIL

SET,

2.

n

FIGURE

2. DRIVING

1

ROLL

SOLID

SUPPORT

OUT

Testing

Redistribution or publication of this document by any means, is strictly prohibited.

Armature

lor Grounds:

Touch one ohmmeter

lead to a commutator bar and then touch the other lead

to armature shaft and core laminations. Alow resistance

reading indicates a grounded armature. Replace grounded armature with a new part. See Figure

3.

Testing for Opens:

Touch one ohmmeter lead to a commutator bar and then systematically touch the other lead to each

of

the remaining commutator bars. A high resistance reading indicates an open circuit between the commutator bars and armature windings. Replace an open armature with a new part.

ES-1614

FIGURE

Testing for

TESTING ARMATURE FOR GROUNDS

3.

Shorts:

Use a growler (Figure

4)

for locating shorts in the armature. Place armature in growler and hold a thin steel blade (e.g. hacksaw blade) parallel to the core and just above the armature while slowly rotat-

ing

armature

in

growler. A shorted armature will cause the blade to vibrate and be attracted to the core. Replace a shorted armature with a new part.

Brush

replace

0.425

Inspection:

if

worn less than

INCH

Measure brushes (Figure

.425

inch.(ll mm).

FIGURE 5. BRUSH INSPECTION

5)

and

E3-1610

HACK

SAW

BUQE

FIGURE

4.

TESTING ARMATURE FOR SHORTS

m

ES-1615

2

TORQUE TO

Redistribution or publication of this document by any means, is strictly prohibited.

5-10

IN-LBS

(.57

-

1.13

Nm)

Assembly

1.

Wipe

off

all

dirt

and oil from starter components

using a clean cloth or blow

off

dirt with filtered, low

pressure compressed air.

-1

Oil on armature wi// damage

Do

starter.

not immerse bearings in cleaning fluid. Use a brush dipped in clean engine oil for removing dirt from bearings. Avoid

geffing oil on brushes or commutator.

FIGURE

6.

BRUSH

ENDCAP

2.

Mount brush springs on tabs as shown in Figure Using a small screwdriver, turn spring counterclockwise

to

torque

so

contact loop is inside brush holder. Spring should be pushed down mounting tab shoulder.

3.

Push negative brush terminals over through-bolt

holes on brush endcap.

4.

Insert positive brush stud into hole and torque to

25-30

Ib.-in.

(2.83-3.39

5.

Using asmall screwdriver inserted into brush spring

contact loop, bend the spring back

Nom).

to

allow each brush to be inserted into holder. Be sure all brush wires are facing up.

Es-1612

6.

of

to

3

6.

Redistribution or publication of this document by any means, is strictly prohibited.

If

the brushesareat least

0.430

inch

(10.9

mm) long,

rest the brush springs against the sides of brushes

to keep them clear during armature installation. See

Figure

7.

Place washer on commutator end

of

shaft and put armature into brush endcap. Push the four brushes toward commutator, making sure springs are properly positioned on brushes. Recheck to be sure spring is pushed all the way down on mounting tab.

8.

Make sure all brush wires are clear of commutator and that uninsulated portions

of

insulated wires do not touch inside diameter of housing. Uninsulated portions of wires must also not touch adjacent brush boxes.

9.

Place magnetic housing over armature. Use a nut

driver over the end

of

shaft to hold down armature

and endcap.

10.

Place spring washer and flat washer on shaft as shown in Figure

11.

Place mounting bracket on motor with exposed end

of

sleeve bearing and through-bolt"lead-ins"

8.

inside of motor. The "flat" near one mounting hole should line up with the positive stud on end cap

through-bolts will line up.

12.

Insert the through-bolts and torque to

(3.96-5.09

13.

Wipedustfrom helix and gearand applya light coat

of

GE

inside diameter

Nam).

Versilube

322-L

on outside diameter

of

gear and unchamfered end

35-45

gear. Place clutch and helix assembly on motor shaft with flats engaged in clutch hole.

of

to

the

so

Ib. in.

helix,

,

of

FIGURE

7.

RESTING BRUSH SPRING

4

ON

BRUSH SIDE

ES1611

METAL

Redistribution or publication of this document by any means, is strictly prohibited.

SPRING

RETAINER

&

SPRING

WASHFR

WASHER

\

1

I16 INCH

WASHER

1

!,URN

SPRING

COVER

RETURN

SPRING

FIGURE

14.

H

Refurn

A.

B.

C. Support the plastic retainer with a vise or other

Spring

is

Unassembled:

Place 1-1/16 inch

shaft With chamfered side of shaft hole up, place plas-

tic retainer on shaft and line up hole with hole in shaft.

solid surface. Using a and hammer, drive in a new roll pin. The pin should be driven in about mm) from the edge of the plastic retainer or

is

evenly spaced from each side.

O.D.

washer over end

5/32

to

1

/8

1

/loth of an inch

inch nail set

MOUNTING

EMCKET

8.

STARTER ASSEMBLY

of

(2.5

so

its

I

D.

Place spring cover over top of plastic retainer, then the return spring on top of the retainer.

E.

With washer placed over point of plastic retainer, push metal retainer into hole of plastic retainer

15. Mount starter on generator stator housing using capscrews, lockwashers and nuts. Tighten mounting screws to

16.

Connect generator set positive

starter terminal. Connect generator set negative terminal to generator set starting battery.

as

~

/--

far as it will go.

30-33

Ib-ft (41

-45

Nom).

(+)

battery cable to

(-)

5

Redistribution or publication of this document by any means, is strictly prohibited.

Supplement

Redistribution or publication of this document by any means, is strictly prohibited.

Date:

Insert

PURPOSE

This

supplement reflects the following manual updates:

Page

1

(for

units

throttle ence

to

equipped

stop,

mixture adjustment, and float setting; in refer-

like information found

with

on

a

Nikki

carburetor) - New

pages

6-13

11-86

with

Ti

NHE-NHEL

Number:

to

6-16.

940-1042

-

Service Manual

940-0502

Nikki

Redistribution or publication of this document by any means, is strictly prohibited.

Carburetor - Throttle

Mixture Adjustment,

Throtlle

Stop

(/d/e Adjust):

Stop,

Fuel

and

Float

Setting

Connect a frequency meter to generator set. Start the generator set and operate at no-load. Turn in the throttle stop screw (idle adjust) to contact the throttle levertab. While adjusting screw, pull the governor linkage toward the engine and monitor the frequency meter. Adjust the screw to obtain the following setting:

0

60

Hz Model

50

Hz Model

-

55

f

1

hertz/1650 * 30 r/min.

45

f

1 hertz/1350 k 30 r/min.

Release governor linkage and check unit frequency and

voltage. Refer to Governor Adjustments in section

6

of service manual. Perform necessary adjustments to achieve proper setting.

Mixture

Screw

Adjustments:

If generator set voltage and frequency (rimin) cannot be satisfactory adjusted, and the generator set operation

is

erratic, stop the generator set and review the following idle and main fuel mixture screw adjustments.

IDLE

ADJUSTMENT STOP

SCREW

CAP

LEVER

FIGURE

1.

THROTTLE

ADJUSTMENT SCREWS

THROTTLE

SCREW

(IDLE

ADJUSI)

ADJUSTMENT

SCREW

STOP,

AND FUEL MIXTURE

FS-1691

A.

Idle mixture screw adjustment:

0

Carefully remove screw adjustment limiter cap.

0

Using a screwdriver, carefully turn the idle mixture screw inward until lightly seated, and then back out exactly one

0

Carefully replace screw adjustment limiter cap

(1)

full turn.

over screw head, with limiter lever located at the

LOW

altitude position.

Takecarenottochangesettingand confirm that limiter cap

is

fully

seated

over

screw head.

B.

Main mixture screw adjustment:

0

Carefully remove screw adjustment limiter cap.

0

Turn the main mixture screw inward until lightly seated, and then back out exactly one and onequarter

0

Carefully replace screw adjustment limiter cap

(1-1

/4)

full turns out.

over screw head, with limiter lever located at the

LOW

altitude position.

Take care not

is

fully

Review Governor Adjustments

seated

to

changesetting and confirm that limiter cap

over

screw head.

in

section

6.

Add and

remove a full load several times to make certain the generator set does not bog down or hunt. Stop generator set, remove meter(s) and

tools,

and close

up

genera-

tor set compartment.

F/oatSeffing:To

adjustthe float, the carburetor must be removed from the generator set. Refer to Carburetor Overhaul - Removal, Cleaning, and Reassembly instructions in section 6 of the service manual.

Perform similar procedures to adjust the float; by bending the tab and checking proper float position. The Nikki carburetor float position is measured from the carburetor housing to the far side (bottom side) of the float. Proper float adjustment should reflecta measurement of

.59

to .63 inch (15 to

059-0.63

(15-16

IN.

rnrn)

r

16

mm).

luw

TOADJUST

t

BOWL

I

FLANGE

GASKET TAB CONTACTING

FIGURE 2. FLOATLEVEL

HEAD OF PIN. WITH

FULL WEIGHT OF FLOAT

COMPRESSING INLET

VALVE SPRING

FS-1611

1

Table

Redistribution or publication of this document by any means, is strictly prohibited.

of

Contents

TITLE

SAFETY PRECAUTIONS SECTION 1

About This Manual

Model Identification SECTION 2 SECTION 3 . DIMENSIONS AND CLEARANCES

SECTION

Troubleshooting Special Tools

Safety Considerations.,

Generator Set Removal SECTION 6

Introduction

Troubleshooting Engine Primary Systems

Exhaust System

Cooling System

Ignition System

Crankcase Ventilation System

Governor

Fuel System

SECTION

Introduction

NHE Control Description

NHE Control Operation NHE Control Troubleshooting NHEL Control Description NHEL Control Operation NHEL Control Troubleshooting

SECTION 8

Introduction Generator Description Generator Operation Generator Troubleshooting Generator Service Brushes and Slip Rings Transformer Voltage Adjustments Generator Testing

SECTION 9

General Oil Filter and Adapter Cylinder Heads Valve System

c

Gear Cover Governor Cup Timing Gears and Camshaft Lubrication System

Piston Assembly

.

INTRODUCTION

.

SPECIFICATIONS

4

-TORQUE SPECIFICATIONS

5 . PREPARING TO SERVICE

..............................................................................

.

ENGINE PRIMARY SYSTEMS

...............................................................................

............................................................................

................................................................................

.

Gasoline

.

LP Gas

7

.

CONTROL

...............................................................................

.

GENERATOR

...............................................................................

.

ENGINE BLOCK ASSEMBLY

...................................................................................

.........................................................

..............................................................................

................................................................................

.............................................................................

......................................................

Inside Front Cover

...............................................................

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?

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I

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PAGE

1.1

2.1

3.1

4.1

-5-1

5.1

5.2

6.1

6.4

6.7

6.8

6-10

6-11

6-12 6-19

7.1

7.2

7.4

7.8

7.9

7-11

8.1

8.3

8.8 8-11 8-13

8-13

9.1

-9-1

9.2

9.6

.9.6

9.7

9.8

iii

Table

Redistribution or publication of this document by any means, is strictly prohibited.

of

Contents (continued)

TITLE

Crankshaft Cylinder Block Bearings

Oil

Seals

SECTION

Mounting Lubrication Wiring

Initial Start Adjustments Output Check Exhaust System Fuel System Control Mechanical

..............................................................................

...........................................................................

................................................................................

10

-SERVICE CHECKLIST

................................................................................

.............................................................................. 10-1

..................................................................................

...........................................................................

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.......................................................

..................................................................

PAGE

9-12

9-12 9-15 9-16

10-1

10-2

..

.

iv

Section

Redistribution or publication of this document by any means, is strictly prohibited.

1

-

Introduction

The model

designate various features typical model number is broken down to illustrate:

,

This manual provides complete service information for Onan generator sets, for the experienced serviceperson. Subjects covered include: troubleshooting, disassembly, repair, reassembly, and adjustments for

engine, generator, and control. The serviceperson

must possess thorough knowledge

bustion engine principles, and basic knowledge of electrical fundamentals. Refer to other Onan publications, such as Electrical/MechanicaI Fundamentals (932-0408), Onan Generator Training Manual (932-

0404), Operators Manual NHE GenSet (940-0122), and Installation Manual NHE GenSet (940-0622), for additional information.

Read all service and procedures completely, observ-

ing all cautions and warnings, before beginning any repair work. The generator set installation must main-

tain compliance with the applicable recreational vehicle codes and standards. The most critical areas of concern are the exhaust system, fuel system, electrical wiring, compartment construction, and ventilation system. Improper servicing can create an unsafe

installation that might cause serious personal injury

or death,

ABOUT

NHE-NHEL

or

damage to the vehicle or equipment.

THIS

MANUAL

series recreational vehicle

of

internal com-

1

1.

Kilowatt rating

2.

Series identification NHE NHEL

Voltage code

3.

1

4.

Starting method

R

Factory code for designating modifications,

5.

options, Specification letter. Advances when the factory

6.

makes production modifications which affect all models.

number

2

-

Gasoline fueled

-

LPG fueled

-

120 volts

-

Remote

or

special features.

consists

3

of

code

segments

or

options. The following

4

5

which

6

<-

Always supply the complete Model Number, Spec Number, and Serial Number as shown on the genera-

tor set nameplate (Figure

Onan Dealer necessary to identify your generator set when ordering replacement parts.

Always use genuine Onan replacement parts obtained from an authorized Onan Dealer

tor.

tended for automotive use) often look similar but

might not perform to Onan specifications. Only genuine Onan replacement parts are designed and tested for specific applications to ensure reliable service and dependable operation.

MODEL IDENTIFICATION

or

Distributor. This information is

Universal type replacement parts (usually in-

INCORRECT SERVICE

SEVERE

PERSONNEL MUST BE QUALIFIED MECHA NlCA

AC

1-1)

when contacting an

or

Distribu-

I

AWARNING

OR

REPLACEMENT OF PARTS CAN RESULT IN

PERSONAL INJURY AND/OR EQUIPMENT DAMAGE. SERVICE

TO

L

SERVICE.

I

PERFORM ELECTRICAL AND/OR

Volts

DCV

RPM

FIGURE

Bat.

1.1.

ONAN NAMEPLATE

1-1

M-1572

Redistribution or publication of this document by any means, is strictly prohibited.

1-2

Section

Redistribution or publication of this document by any means, is strictly prohibited.

2

=

Specifications

-

MODELS

GENERAL

Engine Design Generator Design Output Ratings

Starting System Engine Speed

Weight

Displacement Compression Ratio Bore

Stroke Oil Capacity (With Filter)

1

I

NHE

Four Cycle, Air Cooled,

Revolving Field, Four Pole

Unity Power Factor

Automotive Type Starter,

60.0

3.56

3.00

1800

(119

In3

in. In.

4

Qt.

r/min

262

(983.0

7.0:l (90.42

(76.20

(3.8

1

I

bs

kg)

L)

Two

cm3)

mm)

NHEL

Cylinder

12

Volts

Ventilation (Free Area)

Fuel

GENERATOR DETAl LS

Watts Volts

120

Amps at Frequency (Hertz) Phase Wires Battery Charge (fixed)

TUNE-UP SPECS

Check Spark Plug Gap

Point Gap

Valve Lash

Intake Exhaust

Volts

85

in.2

(548.4

cm2)

Lead-Free or Regular LPG (Propane

Gasoline Liquid Withdrawal)

6500 6300

120

54.2 52.5 60

Single

2

0-1 Amp

0.025

in.

(0.64

0.016

In.

(0.41

mm) mm)

0.025

0.021

1

I

0.005 In.

0.01

3

In.

(0.1

27

(0.330

In. In.

mm)

(0.64 (0.53

mm)

Redistribution or publication of this document by any means, is strictly prohibited.

2-2

Section

Redistribution or publication of this document by any means, is strictly prohibited.

Models

3

-

Dimensions/Clearances

6.5

NHEAND6.3

NHEL

CYLINDERS AND PISTON ASSEMBLY

Cylinder Bore (Std. Size honed)

Cylinder Taper (Max)

Cylinder Out Round (Max)

Clearance in Cy1 i nder

Ring Gap

Piston Ring #1 (top) Groove Width

Piston Ring #2 Groove Width

Piston Ring #3 Groove Width

of

Dimensions

3.5625-3.5635

(90.488-90.513 rnm)

0.0070-0.0090

(0.1 78-0.229 rnm)

0.01

(0.254-0.508 mm)

0.080-0.081

(2.032-2.057 mm)

0.080-0.081

(2.032-2.057 mrn)

0.188-0.1 89

(4.775-4.801 mrn)

not

in

parentheses are

INCHES

0.003

(0.076 mm)

0.003

(0.076 rnm)

00-0.0200

.

Rod

(Top)

Journal

Piston Ring #1 Side Clearance

Piston Pin Diameter

Piston Pin Fit In Rod

Connecting Rod

Side Clearance Connecting Rod

Bearing Clearance CRANKSHAFT AND

CAMSHAFT Crankshaft Main Bearing

Journal Diameter

Crankshaft Bearing Diameter

Crankshaft Main

Bearing Diameter

I

0.002-0.008

(0.051-0.203 mrn)

0.7500-0.7502

(19.05-19.06 mrn)

0.00005-0.00055

(0.001-0.014 mrn)

0.0020-0.01 60

(0.051-0.406 mrn)

0.0005-0.0028

(0.013-0.071 mrn)

Dimensions not

INCHES

1.9992-2.0000

(50.780-50.800 rnm)

1.6252-1.6260

(41.280-41.300)

2.001 5-2.0040

(50.838-50.902 mm)

in

parentheses are

3-1

DimensionsKlearances (continued)

Redistribution or publication of this document by any means, is strictly prohibited.

Models

Crankshaft Main Bearing Clearance

Crankshaft End

Play

Cams haft Journal Diameter

Camshaft Bearing Diameter

Camshaft Bearing Clearance

Camshaft End Play

VALVES

AND

LIFTERS

Valve Spring Free Length

Valve Spring Compressed Length

6.5

NHEAND

6.3

NHEL

0.0025-0.0038

(0.064-0.097

mm)

0.005-0.009

(0.13-0.23 mm)

1.3740-1.3745

(34.900-34.912 mm)

1.376-1.377

(34.950-34.976

mm)

0.001 5-0.0030

(0.038-0.076

mrn)

0.0030-0.01 20

(0.076-0.305

mrn)

Dimensions not in parentheses are

INCHES

1.6620

(42.214 mm)

1.3750

(34.925 mm)

Valve Spring Tension Open

Valve Spring Tension

Closed Valve Face Angle Valve Seat Angle Valve Stem

Diameter (Intake) Valve Stem

Diameter (Exhaust) Valve Guide

Diameter

Valve Stem Clearance

(Intake)

Valve Stem Clearance

(Exhaust)

Valve Lifter Diameter

71-79

Ibs

(32-36 kg)

38-42

Ibs

(1

7-1 9 kg)

44 degrees

45 degrees

0.3425-0.3430

(8.700-8.712 mm)

0.341 0-0.341

(8.661 -8.674 m m)

0.344-0.346

(8.738-8.788

mm)

0.001 0-0.0025

(0.025-0.064 mm)

0.0025-0.0040

(0.064-0.102 mm)

0.7475-0.7480

(1

8.987-1 8.999 mm)

5

Valve Lifter Bore Diameter

0.7505-0.7515

(19.063-19.088 mm)

Dirnensions/Clearances (continued)

Redistribution or publication of this document by any means, is strictly prohibited.

Models

Valve Lifter

Block Clearance

Valve Seat

Diameter (Intake)

Valve Seat

Diameter (Exhaust)

Valve Seat Bore Diameter (Intake)

Valve Seat Bore

Diameter (Exhaust)

To

6.5

NHEAND

0.001

(0.038-0.076

1.5690-1

(39.853-39.878 m m)

1.2550-1.2560

-

(31.877-31.902 rnm)

1.5645-1 S655

(39.738-39.764 mm)

1.251 0-1.2520

(31.775-31.801 rnm)

6.3

5-0.0030

mm)

S700

NHEL

.

3-3

Redistribution or publication of this document by any means, is strictly prohibited.

3-4

Section

Redistribution or publication of this document by any means, is strictly prohibited.

Models

TORQUE SPECIFICATIONS

4

-

Torque

Use

engine

EXCEPT the spark plug and rotor through-bolt threads

Specifications

NHE

AND NHEL

oil

as a lubricant

for

all threads

~~

FOOT-POUNDS

Cylinder Head (Cold) 18-20 (24-27 Connecting Rod 27-29 (37-39)

Rear Bearing Plate

Oil

Base 18-23 (24-31) Gearcase Cover Spark Plug Exhaust Manifold 20-23 (27-31

Intake Manifold 20-23 (27-31)

Other 3/8 Cylinder Block Nuts

Oil

Pump

Rotor Through-Bolt

25-28 (34-38) 50-55 (68-75) Flywheel Mounting Screw

0

8-1

7-9 (9-1 2)

18-23 (24-31)

7-9 (1

45-55

(NEWTON-METRES)

(11-14)

0-1

2)

(61-75)

)

Stator Clamp Screws Adapter to Engine

Mounting Screws

to

Adapter Mounting Screws

Rear Vibration Isolator

Flange to Drip

Tray Screws

Front Vibration Isolator -Flange to

Base Screws

Generator

-

Center Screw 30-33 (41 -45)

Oil

30-33 (41-45) Starter Mounting Screws

10-12 (11-16)

25-27 (34-37)

25

10-1 2 (11-16)

19-22 (26-30)

(34)

4-1

Redistribution or publication of this document by any means, is strictly prohibited.

4-2

Section

Redistribution or publication of this document by any means, is strictly prohibited.

5

-

Preparing

to

Service

TROUBLESHOOTING

Before servicing the generator set, locate and isolate

the problem using systematic troubleshooting pro-

To

cedures. generator set into four logical groups and provides a separate section for each:

Engine - Primary Systems Control Generator

0

Engine - Block Assembly

This manual provides troubleshooting tables to help

locate the cause of various malfunctions. Some rnal-

functions may have several causes. Thus, several

likely problem areas may have to be investigated to

isolate the source of the malfunction. Because of the complexity of the product, troubleshooting tables cannot list every malfunction and its cause. In some

situations, the serviceperson will have to rely on experience and knowledge and correct the problem.

The following special tools may be required to service the generator set. Some of these tools can be

purchased from Onan, while others must be purchased from outside suppliers. Tool Catalog

0019

(available from Onan Dealers or Distributors)

lists all tools available from Onan.

Engine

aid servicing, this manual divides the

of

the product to locate

SPECIAL

TOOLS

Tools

#900-

Slide hammer

Piston groove cleaner

Outside micrometer set,

0-4

In. (1-102 mm)

Telescoping gauge set,

0.5-6

In.

(12-154

Hole gauge,

0.300-0.400

Plasti-gage bearing clearance guide

Generator and Control

Lead or dead-blow hammer

Battery hydrometer

VOM

m ul t i-tester Frequency meter Armature growler

J

um per wires

Load test panel

SAFETY

Always consider the safety aspects

procedure. Generator sets present several hazards

that the serviceperson must be aware of if the job is to

be completed safely. Read through the safety precau-

tions listed on the inside cover and familiarize yourself with the various hazards shown in Table Once th-e hazards are known, approach the safety conscious attitude. Being safety conscious is the most effective way to avoid injury to yourself or others. Reduce the chance that an accidentwill occur by adopting the following safeguards.

mm)

In.

(7.50-1

1.00

mm)

Tools

CONSIDERATIONS

of

any service

job

5-1.

with a

Torque wrench,

Feeler gauge Pressure gauge

Spark plug gap gauge

Carburetor adjustment wrench Points adjustment tool Flywheel puller

Snap ring pliers

Gear puller with puller ring Cylinder ridge reamer Combination main and cam bearing remover Combination main and cam bearing driver Oil seal loader and driver Piston ring compressor Piston ring spreader

Cylinder hone Valve seat cutter Valve spring compressor Valve lock replacer

--

Valve seat driver

0-175

Ft-Lbs

-

(0-240

Nom)

Safeguards to Avoid Hazards

Use Personal Protection-When the situation calls

for it, protect your body by wearing the approp-

riate safety equipment. Protective clothing includes such items as safety shoes, gloves, safety glasses and hard hats. Leave ringsand jewelry and don't wear loose clothing that might get caught on equipment.

Work to Reduce the Hazard -The workshop area and all pieces of equipment used can contribute to reducing the hazard potential. Keep guards and shields in place on equipment in good working condition. Store flammable liquids proved containers away from open flame. Keep the workshop clean and well-lighted, and provide adequate ventilation. Keep safety equipment nearby and be prepared to respond to an emergency.

'5-1

fire

extinguishers and

in

off

ap-

TABLE

Redistribution or publication of this document by any means, is strictly prohibited.

5-1.

HAZARDS AND THEIR SOURCE

0

Fire and explosions

-Leading fuel Gasoline vapor

LP gas vapor

-Hydrogen gas from charging battery

-Oily rags improperly stored

-Flammable liquids improperly stored

0

Burns

-Hot exhaust pipes

-Hot engine and generator surfaces

-Hot engine oil

-Electrical short in DC wiring

0

Poisonous Gases

-Carbon monoxide from faulty exhaust

-LP gas leaking into coach interior

-Operating generator set where

exhaust gases can accumulate

e

Develop Safe Work Habits - Unsafe actions are identified as the cause of most accidents involving the use of tools and machines. Be familiar with theequipment and know how to use

it

safely. Use the correct tool for the job and check its condition before starting. Observe the warnings and cautions in this manual and take special precautions when working around electrical equipment. Don’t work alone if possible and don’t take risks.

Be prepared if an accident does occur. Numerous agencies such as the Red Cross and your local police and fire departments offer basic courses in first aid,

mouth-to-mouth resuscitation, and fire control. Take

advantage of these offerings

so

you are ready to respond when an accident happens. Learn to be Safety-Conscious and make safe practices a part of

your work routine.

GENERATOR SET REMOVAL

Someservice procedures will require that the generator set be removed from the coach. While there are

many variations, generator set installations are

generally classified as either conventional compart-

ment mount or under floor mount. In a conventional

compartment mount installation, a special compart-

ment (see Figure the generator set. The compartment is constructed with a vapor tight barrier that seals off the generator set from the coach interior. The generator set is usually fastened to the floor of the compartment which must be able to support the weight of the set. Access to the compartment is through a door located in the exterior of the coach.

5-1)

is built into the coach to house

Electrical shock (AC)

-Improper load connections

-Faulty

RV

wiring

-Faulty electrical appliance

-Faulty generator set wiring Rotating Machinery

-Flywheel fan guard not in place Slippery Surfaces

-Leaking or spilled oil Heavy Objects

-Removing generator set from

RV

-Removing heavy components

In an under floor mount installation (see Figure

5-2),

a special housing is used to suspend the generator set from the underside of the coach. The housing bolts to special support members that are built into

the coach framework. The housing is mounted near

the exterior of the coach and limited access is provided through a door located in the exterior of the coach.

Because of the wide variety of generator set installations, it is not possible to specify the exact removal

proceduresfor each generator set. If, after examining the installation, a satisfactory method for removing the set cannot be determined, contact the RV coach

manufacturer to obtain their recommendations

before attempting to remove the set from the coach.

Generator sets are heavy and can

-1

during removal.

cause personal injury if dropped

Use

adequate lifting devices fo pro-

vide sufficient support for fhe set. Keep hands and feef clear while lifthg.

Special fuel handling procedures are required when

removing an LP gas (propane) powered set. The fuel system must be purged of LP gas before the set can be safely removed from the coach. Follow the purg-

ing procedure described in the next section before attempting to remove an LP gas powered set. If the generator set is powered by gasoline, proceed to the appropriate set removal section.

LP-Gas

To

(Propane) Purging Procedure

purge the LP gas from the set fuel system, close

5-2

the shut-off valve at the fuel tank and then start the

Redistribution or publication of this document by any means, is strictly prohibited.

generatorset. Allow the generator set to operate until it runs out of fuel. Crank the set a few times after

it

stops to make sure the fuel system is completely

all

LP

purged of

gas fuel.

8.

On gasoline fueled sets, turn off the fuel shutoff valve in the compartment and disconnect the fuel

line at the fuel pump. Securely plug the end of the fuel line to prevent leakage or accumulation of explosive gasoline vapor.

If the generator set cannot be operated, move the

RV

coach to an outdoor location that is well ventilated and is away from fire or flame. Disconnect both the vehicle negative set negative

(-)

battery cable and the generator

(-)

battery cable from their respective

battery terminals. Close the fuel shutoff valves at the fuel tank for both thegeneratorset fuel supply system and the appliance (stove, heater, etc) fuel supply system. In addition, close the fuel shutoff valves at each appliance.

Fuel presents the hazard

of

fire or

explosion which can cause severe personal injury or death. Eliminate all possible sources of ignition such as pilot lights or sparking electrlcai equipment before purging LP gas from the fuel system. Provide adequate ventilation to dissipate LP gas as it

is

released.

Slightly open the fuel line (flexible section) at the solenoid valve just enough to allow the LP gas to slowly escape. Don’t open the fitting too much or a

large quantity of gas will be released.

Disconnect the fuel supply hose from the carburetor and hold primer button on the regulator to release

it

clear of the set. Press in and hold the

LP

gas from

the set fuel system. When no more gas can be heard

escaping from the open end

of

the fuel supply hose,

reconnect the hose to the carburetor and proceed to

the appropriate set removal section.

Fuel presents the hazard of fire

or explosion which can cause severe personal injury or death. Make certain all fuel line openings are plugged to prevent gasoline vapor from accumulating.

On

LP

Gas (propane) fueled sets, disconnectthe fuel line (afterpurging) at thesolenoid valve and plug end of the fuel line to prevent entrance of dirt.

Removing Conventional Compartment Mounted

From

Set

RV

When the generator set has been disconnected from the electrical, exhaust, and fuel systems, examine the

set mounting and support system. Locate all mounting bolts and support members for the set. In most installations, the generator set drip tray will be bolted

to the coach framework. Depending on the installation, theset may be removable from theside, back, or

bottom.

Verify that the generator set is adequately supported before loosening any

of

the mounting bolts or support members. The most satisfactory way to lift or move the generator set is to use a fork lift truck.

The generator set Is heavy and can

lZiBWGl

cause severe personal injury if dropped during removal. Use the recommended removal techniques and keep hands and feet clear while removing mounting bolts.

Disconnecting Set

Disconnect the following items from the generator

set.

1.

Disconnect the vehicle negative at the battery terminal.

2.

Disconnect the generator set negative

cable at the battery terminal.

3.

Disconnect the generator set positive

cable from the start solenoid.

4.

Disconnect the remotecontrol wire plug from the

generator set control.

5.

Disconnect the generator load wires at the electrical system junction box. Tag the

wires if necessary for positive identification.

6.

Loosen the conduit connector and pull the load

wires and flexible conduit free of the junction

box.

7.

Disconnect the muffler from the exhaust manifold at the flange connection and disconnect any support brackets or hangers that connect the

muffler to the set.

from

RV

Systems

(-)

battery cable

(-)

battery

(+)

battery

RV

circuit

5-3

BP

FIGURE

COMPARTMENT MOUNT

COMPARTMENT

5-1.

TYPICAL CONVENTIONAL

INSTALLATION

FLOOR

EXS-1111

Removing Underfloor Mounted Set

Redistribution or publication of this document by any means, is strictly prohibited.

From

RV

When the generator set has been disconnected from the electrical, exhaust, and fuel systems. the set may be partially removed for limited service or completely removed from the

RV

for major service. The generator set is mounted on a support tray which serves as the bottom of the underfloor housing.The inneredge of the support tray is hinged to the rear panel assembly. The outer edge of the support tray is bolted to a support bracket.

A

front and rear panel assembly

serve as sides to complete the housing. The generator set is completely suspended under-

neath the

RV

coach by the housing assembly. To avoid dropping the set during removal, follow the recommended set removal procedures.

!2EBWil

The generator set

cause severe personal injury

is

heavy and can

if

dropped during removal. Use fhe recommended removai techniques and keep hands and feef clear while removing mounfing

Partial Set Removal:

boifs.

Park the recreational vehicle on a level as possible surface (surface must support floor jack wheels). Then follow these instructions very carefully.

If

generator set will be left in the down (tilted) position

than

30

minutes, first drain the

oil.

for

more

Oil in the engine cylinders can

k&&!@@d

cause engine damage during sfart-

ingattempfs. Oiican enter the engine cyiinders when

is

in

the

io

the generator set not ieave the generator set

30

than

It is assumed that disconnecting the fuel, exhaustetc. has already been performed as described on the previous page.

minufes if the

1.

Put the vehicle in its Dark Dosition, lock the

wered (tilted) position. Do

in

this

position for more

oil

has not been drained.

if

necessary

brakes, and remove the’ignition key. Make sure no one moves the vehicle while performing this procedure.

Dropping the generator sef creafes the hazard of severe

no

and

one that

personal injury or deafh. Make sure moves fhe vehicle during this procedure

Is

procedure as

instructed.

2.

Useafloorjacksimilarto theoneshown in Figure

5-3,

and position the floor jack under the rein-

forcement ribs

3.

Raise the floor jack until

performed very carefuiiy and only

of

the drip tray as shown.

it

just makes contact with the drip tray, then just put a little upward pressure under the drip tray.

4.

Remove the four bolts from the front support bracket, and remove the support bracket itself.

FIGURE

5-2.

SUPPORT

TYPICAL

BRACKET

UNDER-FLOOR

5-4

EXS-1122

INSTALLATION

FIGURE

Redistribution or publication of this document by any means, is strictly prohibited.

5-3.

PARTIAL

SET

REMOVAL

PLACE

FLOOR

DRIP

JACK

TRAY

UNDER

REINFORCEMENT

M-1600

RIBS

This might require slight adjustment of the floor

jack, either slight raising

5.

Once the support bracket is removed, all the

or

lowering of the jack.

weight of the-generator set on that side is on the floor jack. Slowly lower the floor jack, being care-

to

allow the floor jack

ful

to

roll as the generator

set swings downward.

6.

Onan suggests

you

put some wood blocks under thedriptray assernblyso that youcan rernovethe floor jack. This will allow you more access room for the maintenance or service procedure.

Dropping the generafor sef

of

creates fhe hazard

severe personal injury or deafh. Make sure generator sef

is

resfing securely before removing floor jack.

Complete Set Removal:

Park the recreational vehicle on a level surface. Then follow these steps very carefully.

It is assumed that disconecting the fuel, exhaust, etc. has already been performed

as

described on the pre-

vious page.

1.

Put the vehicle in its park position, lock the brakes, and remove the ignition key. Make sure

no one moves the vehicle while performing this procedure.

5-5

Dropping the generator set

Redistribution or publication of this document by any means, is strictly prohibited.

sure

of

no

creates the hazard

personal injury or death. Make

moves the vehicle during

this

procedure and that the procedure is performed very carefully and only as instructed.

2.

Use a fork tray at the points shown in Figure wooden block on one fork

lift

truck to support the generator set

5-4.

Place a

so

the set will remain

level.

,

severe

one

3.

Lift the fork lift just

so

it makes contact with the drip tray, then just put a little upward pressure under the tray. Verify the weight

of

the generator

set supported by the forks before proceeding.

4.

Remove the bolts that secure the side support to

the drip tray and the underfloor bracket.

5.

Lift generator up slightly until safety catch on

side support is clear of tray. Pull support forward and upward until disengaged from tray and underfloor bracket.

6.

Remove the sidesupport to provide the clearance needed for lowering the set.

7.

Remove the safety catch from the center of each hinge assembly and then remove the U-shaped binge pin.

8.

Slowly lower the generator until

it

is clear obstructions and can be moved out from under the recreational vehicle.

of

all

FORK

FIGURE

LIFT

A'

5-4.

COMPLETE SET

M-1601

REMOVAL

5-6

Section 6. Engine

Redistribution or publication of this document by any means, is strictly prohibited.

INTRO D UCTl ON

The engine primary systems include the following:

0

Cooling System

0

Exhaust System

0

Ignition System

0

Starter Motor

0

Crankcase Ventilation System

0

Governor

0

Fuel System - Gasoline

0

Fuel System - LP Gas Liquid Withdrawal

Primary

The engine primary systems can often be serviced

without removing the generator set from the recrea-

tional vehicle and without major disassembly of the

set. Use the following troubleshooting guide to help locate problems related to the engine primary systems. Refer to Troubleshooting Generator Set Con-

trol for problems related to starting the generator set.

Systems

Trouble

Engine Misfires

Engine Backfires

TROUBLESHOOTING ENGINE

Possible Cause

1. Faulty ignition due to: a. worn or fouled spark plugs

b. worn ignition points.

c. incorrect ignition timing

d.

faulty ignition coil, or

e. faulty plug wires.

2. Lean fuel mixture due to: a. incorrectly adjusted

fuel mixture screws

*b. incorrect float level

c. dirt in carburetor d. vacuum leak.

3.

*Contaminated fuel

4.

*Carburetor icing *Gasoline sets only

~~

1.

Faulty ignition due to: a. incorrect ignition timing

b. incorrect spark plug gap

2. Lean fuel mixture due to: a. incorrectly adjusted

fuel mixture screws

*b. incorrect float level

c. dirt in carburetor

3.

Mechanical damage to engine

,

PRIMARY

1

a. Clean or replace

spark plugs

1

b. Replace breaker points

IC.

Set breaker point gap

1

d. Test coil and replace if

necessary

le. Test spark plug wires

and replace if faulty

2a. Adjust carburetor main

and idle adjustment screws

2b. Adjust carburetor

float level

2c. Disassemble carburetor

and clean all internal passages

2d. Locate leak and correct as required

3.

Drain fuel tank and

refill with fresh fuel

4.

In cold weather, place air preheater

in winter position

1

a. Adjust breaker point gap

1

b. Reset spark plug gap

2a. Adjust carburetor main

and idle adjustment screws

2b. Adjust carburetor float

level

2c. Disassemble carburetor and

clean all internal passages

3.

See Engine Block Assembly

SYSTEMS

Corrective Action

'Gasoline sets only

6-1

TROUBLESHOOTING ENGINE PRIMARY SYSTEMS

Redistribution or publication of this document by any means, is strictly prohibited.

Trouble

Engine Lacks Power

Possible Cause

1.

Faulty ignition due to: a. incorrect ignition timing

b. incorrect spark plug gap

2.

Dirty air cleaner

3. Restricted fuel flow due to: a. plugged fuel filter or

b. faulty fuel pump

4. Incorrect fuel mixture due to: a. incorrect adjusted

fuel mixture screws,

*b. incorrect float level, or

c. dirt in carburetor

5.

Exhaust system blocked or restricted

6.

Incorrect valve tappet clearance

7.

Excessive engine wear or damage to engine

8.

Carburetor air preheater set incorrectly

*Gasoline Sets Only

Corrective Action

la. Adjust breaker point gap

1

b. Reset spark plug gap

2.

Replace air cleaner

3a. Clean fuel filter

3b. Test fuel pump and repair

or replace if faulty

4a. Adjust carburetor main and

and idle adjustment screws

4b. Adjust carburetor float level 4c. Disassemble carburetor and

clean all internal passages

5.

Locate and remove cause of blockage.

6.

Adjust valve tappets (see

Engine Block Assembly section)

7.

See Engine Block

Assembly section

8.

In hot weather, place air preheater in summer position

Engine

Black Exhaust

1.

Restricted airflow due to dirt or debris blocking air

inlet or outlet

2.

Dirt or oil covering engine cooling fins

3.

Incorrect ignition timing

4.

Lean fuel mixture due a. incorrectly adjusted

fuel mixture screws

"b. incorrect float level or

c. dirt in carburetor

*Gasoline sets only

1.

Rich fuel mixture due to: a. dirty air cleaner.

"b. choke sticking,

c. incorrectly adjusted fuel

mixture screws

d. dirt in carburetor

*Gasoline sets only

to

1.

Clear away any debris that

may restrict airflow to set. Do not use compartment for storage area.

2.

Clean away all dirt and oil from engine cooling fins

3.

Adjust breaker point gap

4a. Adjust carburetor main and

idle adjustment screws

4b. Adjust carburetor float

level

4c. Disassemble carburetor and

clean all internal passages.

la. Replace air cleaner 1 b. Clean choke and choke linkage

IC.

Adjust carburetor idle and main adjustment screws

Id. Disassemble carburetor and

clean all internal passages

I

6-2

TROUBLESHOOTING ENGINE

Redistribution or publication of this document by any means, is strictly prohibited.

PRIMARY

SYSTEMS

Trouble

Engine Hunts or Surges

High Oil Consumption

Possible Cause

1.

Sticking or binding

governor linkage

2.

Incorrect governor adjustment

3.

Faulty governor spring

4. Incorrect fuel mixture due to: a. incorrectly adjusted

fuel mixture screws,

*b. incorrect float level, or

c. dirt in carburetor

5.

Governor mechanism worn excessively

6.

Carburetor icing

*Gasoline sets only

1.

Oil viscosity too light or oil is diluted

Corrective Action

Clean and lubricate

1

a.

governor linkage

2.

Adjust governor speed and

Replace governor spring

-

3.

Replace governor spring Adjust carburetor main and

4a.

idle adjustment screws

4b.

Adjust carburetor float level Disassemble carburetor and

4c.

clean all internal passages

5.

See Engine Block Assembly

section

6.

In

cold weather, place air

preheater in winter position

1.

Drain oil and refill with correct viscosity oil

(Note: New engines sometimes

have high oil consumption during break-in)

Low Oil Pressure

2.

Crankcase breather valve is dirty or defective

3.

Oil leaks

4.

Excessive engine wear

5.

Light loading

1.

Oil viscosity too light or

is

diluted

oil

2.

Low oil level

3.

Low oil pressure switch defective

4.

Faulty oil bypass valve

5.

Excessive engine wear or defective oil pump

2.

Clean crankcase breather

and replace if defective

3.

Locate source of leak and

repair as required

4.

See Engine Block Assembly section

5.

Don't run set at no load for long periods of time

1.

Drain oil and refill with correct viscosity oil

3.

Add oil as required.

3.

Replace oil pressure switch

(see Engine Block Assembly

section)

4.

Inspect oil bypass valve clean or replace as required (see Engine Block Assembly section)

5.

See Engine Block Assembly section

~~

6-3

EXHAUST

Redistribution or publication of this document by any means, is strictly prohibited.

SYSTEM

The condition of the exhaust system is extremely critical on

RV

generator sets because of the possibil-

ity of exhaust gases entering the coach.

The exhaust system must be serviced immediately

reveals leaking joints or connections, loose fasteners, or broken or

damaged components.

if

inspection

Always replace worn components with new original

Do

equipment replacement parts.

not attempt to repair a broken exhaust pipe or manifold by welding and do not replace worn out components with parts

that do not meet factory specifications.

Exhaust presents the hazard of

k%!@!&l

severe personal injury or death. Modifying the exhaust system mlght allow poisonous exhaust gases

to

enter the coach. Use only original equlpment replacement parts when servlclng the exhaust system. Unauthorized modiflcaflons willalso void the warranty and cancel the

UL

Llst/ng/CSA

Cerflflcatlon. Llabl//ty for injury or damages due to unauthorlzed modiilcations becomes the responsibillfy of the person making the change.

Two basic exhaust systems are used with Emerald series generator sets. Figure

6-1

shows a typical

exhaust system for conventional compartment

6-2

mount generator set. Figure

shows a typical exhaust system for an underfloor mount generator set. Separate sections cover the service procedures

for each exhaust system.

Compartment

Mount

Exhaust

System

Compartment mount exhaust systems consist of the exhaust manifold, flange connector, muffler, muffler strap, hanger, clamps, and tailpipe. When service is required, disassembleand reassemble as specified in the following steps.

Disassembly

1.

Loosen the front mufflerclamp, muffler strap, and tailpipe hanger and remove the muffler and tailpipe assembly (see Figure

2.

Remove the screws that secure the flange con-

6-1).

nector to the exhaust manifold and remove the flange connector and asbestos gasket.

Completion set Service section lor the set removal procedures.

Remove the cooling system noise shield and

3.

of

be

the remaining steps requires that thegenerator

removed from the vehicle. Refer

to

the Preparing to

scroll (see Cooling System in this section) to provide access to the exhaust manifold.

4.

Remove the screw that secures the exhaust manifold outlet flange to the exhaust manifold support bracket.

5.

Remove the four exhaust manifold screwsand lift off the exhaust manifold and the two manifold gaskets.

a

SCROl

L

BRACKET

MUFFLER

v,

F

CLAMP

CUTOUT

STRAP

PJ

IGER

FRONT

SET

VIEW

XEXS-1118

FIGURE

6-1.

EXHAUST SYSTEM CONVENTIONAL COMPARTMENT

6-4

If

Redistribution or publication of this document by any means, is strictly prohibited.

set

is

LP-Gas fueled, the fuel vaporizer and regulator are attached to the exhaust manifold. Purge the fuel system of LP gas fuel before disconnecting the fuel line at the vaporizer. See FUEL

mended purging procedures.

Assembly:

and then proceed as indicated.

1-

prevent exhaust leak, installal;g~skets, clamps,

straps, and hardware as speciiied.

1.

Install the exhaust manifold using new gaskets and tighten thefour manifold screws to thespecified torque.

2.

Install the 5/16-18 screw, lock washer, and nut that secure the manifold outlet flange to the manifold support bracket and tighten securely.

Install the cooling system scroll and noise shield

3.

(see Cooling System in this section).

If

no other service is required, install the generator set in the

vehicle before completing the remaining steps.

4.

Install a new gasket between the exhaust manifold and flange connector and secureflangecon-

nector to manifold using 5/16-18 inch screws,

lock washers, and nuts.

5.

Attach the inlet of the muffler to the flange con-

nector using a U-bolt type automotive muffler clamp overlaps flange connector a minimum of 1-1/2 inches Place muffler strap on muffler and position

6. below cutout in bottom of generatorset drip tray. Fasten strap to set L-bracket using a 1/4-20 screw and lock washer. Tighten strap around muffler using a 1/4-20 screw, lock washer and nut.

7.

If

replacing the original tailpipe, refer to Tailpipe Recommendations in this section for selecting and locating the tailpipe. Attach tailpipe to outlet end of muffler and secure using a 1-1/2 inch Ubolt type automatic muffler clamp

8.

Support the tailpipe using a shock mounted support hanger with clamp.

SYSTEM

Obtain the required replacement parts

ONLY.

(38

-

LP-GAS in this section for the recom-

Exhaust gas presents the hazard of

severe Dersonal iniurv or death.

Make certain that muffler inlet pipe

mml.

ONLY.

To

it

replace pipe plug. Inspect exhaust system (visually and audibly) for leaks daily (at least every eight hours

Underfloor Mount

Underfloor mount exhaust systems consist of the exhaust manifold, muffler, clamps, hanger (if quired), and tailpipe. When service is required, disassemble and reassemble as specified in the following

steps.

Disassembly:

Loosen the muffler clamp at the muffler inlet (see

1. Figure 6-2) and remove the muffler support bracket screws.

2.

Loosen tailpipe hanger (if used) and remove the muffler and tailpipe assembly.

Completion of the remaining steps requiresthat the generator set be partially removed from the vehicle. Refer to the Preparing to Service section for the set removal procedures.

3.

Remove the cooling system scroll and noise shield (see Cooling System in this section) to

provide access to the exhaust manifold.

4.

Remove the four exhaust manifold screws and lift off the exhaust manifold and the two manifold gaskets.

If set

is

removed along with theexhaust manifold. See FUELSYSTEM

-

LP-Gas in this section for the vaporirerlregulator removal

and replacement procedures.

Assembly:

@@&@I

prevent exhaust leaks, install all gaskets, clamps,

straps, and hardware as specified.

1.

Install the exhaust manifold using new gaskets

and tighten the four manifold screws to thespecified torque.

2.

Replace the noise shield and scroll (refer to the Cooling System in this section).

of

running time).

Exhaust

LP-Gas fueled, the fuel regulatorlvaporizer must be

Exhaust gas presents the hazard of

severe personal injury or death.

System

re-

To

-1

in exhaust system damage since excessive vibration transfered

ing. Mount muffler and tallpipe hanger brackets

directly above the component supporfed, not at an

angle.

Run the generator set for five minutes and check

9.

entire exhaust system (visually and audibly) for leaks or excessive noise. Correct as required.

Clean spark arrester muffler every 100 hours of

10. operation. Remove 1/8 inch pipe plug in bottom of muffler and run set for five minutes. Then

Angular mounting of muffler and

tailpipe hanger brackets can result

to

the vehicle is caused by angularmount-

6-5

if no other service is required, install the generator set in the vehicle before completing the remaining steps.

3.

Place a U-bolt type automotive muffler clamp in position on the exhaust manifold (near elbow) prior to installing muffler.

Place muffler in position on

4.

that muffler inlet pipe overlaps exhaust manifold a minimum of 1-1/2 inches

Install the two 1/4-20 screws and lock washers

5. that secure the muffler support bracket to the set and tighten muffler clamp.

6.

If replacing the original tailpipe, refer to the Tailpipe Recommendationssection for selecting and locating the tailpipe. Attach tailpipe to outlet end

set

making certain

(38

mm).

EXS-1120

Redistribution or publication of this document by any means, is strictly prohibited.

FIGURE

6-2.

EXHAUST

of muffler and secure using a 1-1/2 inch U-bolt

type automotive muffler clamp

7.

Support the tailpipe using a shock mounted sup-

ONLY.

port hanger with clamp.

Angular mounting of muffler

and tailpipe hanger brackets can resuit in exhaust system damage since excessive vibration transfer to the vehicle is caused by angular mounting. Mount muffler and

tailpipe hanger brackets directly above

not

component supported,

at an angle.

8. Run the generator set for five minutes and check entire exhaust system (visually and audibly) for

leaks or excessive noise.

9.

Clean spark arrester muffler every

100

hours of operation.,Remove 1/8 inch pipe plug in bottom of muffler and run set for five minutes. Then

replace pipe plug. Inspect exhaust system (visually and audibly) for leaks daily (at least every eight hours of running time.

SYSTEM

UNDERFLOOR

MOUNT

Tailpipe Recommendations

Tailpipes are supplied by the

RV

manufacturer and must meet several design specifications to ensure safe generator set operation. If replacing the tailpipe, make certain the replacement part is the same size and configuration as the original part. Refer to the following guidelines for selecting and locating the

tailpipe.

-1

Exhaust gas presents the hazard of

severe personal injury or death.

Exhaust gases can enter the coach interior if the

taiiplpe is damaged, missing, or improperly installed.

Follow the recommended exhaust system replacement procedures to ensure safe operation:

Use 1-3/8 inch

tailpipe.

it

might break due to road shock and vibration.

0

Install exhaust tailpipe at least 3 inches

ID,

18 gauge, rigid steel tubing for

Do

not useflexibleexhausttailpipe since

(76

mm)

away from the fuel tank and any combustible

6-6

material.

Redistribution or publication of this document by any means, is strictly prohibited.

If

3

inches

(76

mm) clearancecannot

be

maintained, install suitable heat shielding be-

tween tailpipe and combustible material or fuel

to

0

tank

Do

prevent

not

terminate the exhaust tailpipe:

excessive

heating.

A. Under a window, door, or any opening that

might allow exhaust gases to enter the coach interior.

B.

8

Ahead of or under the generator compart-

ment air intake to prevent recirculation of

exhaust gases. Terminate tailpipe to the

rear

of the compartment air intake.

C.

Under the fuel tank fill spout to prevent spilled fuel from being ignited by a hot tailpipe.

D.

Under the vehicle to prevent exhaust gases from entering the coach interior through small openings in the underside of the

v

CS-1266

vehicle.

Extend the tailpipe at least

one inch

(25

mm)

FIGURE

6-3.

COOLING

AIR

FLOW

beyond the perimeter of the vehicle. Direct exhaust gases away from windows, doors, or compartment

down

and

away

from the vehicle

heat transfer is greatly reduced and overheating can

occur if the fins are not cleaned.

openings.

The cooling system consists of the noise shield,

0

Do

not connect thegenerator set exhaust tailpipe

to the vehicle exhaust system. Exhaust gases will

be forced into the non-running engine and might be released through the carburetor air inlet.

cylinder air housings, scroll, flywheel, and scroll backplate. When service is necessary, disassemble and assemble the cooling system as specified in the following sections.

Water vapor from the exhaust might also damage the non-running engine.

Disassembly:

Remove the muffler and tailpipe assembly (see Exhaust System in this section) to provide access to the cooling system and then pro-

COOLING

SYSTEM

ceed as indicated.

A constant airflow is critical for engine and generator cooling to prevent excessive heat build-up. All Emerald series generator sets use a Vacu-Flo cooling system to provide the required airflow. With Vacu-Flo cooling, a flywheel fan draws cool air in from the generator end of the compartment (see Figure

6-3).

NOISE

SHIELD

The cool air passes over the cooling fins on the engine and absorbs the heat. The heated air is then discharged through the opening in the bottom of the Vacu-Flo scroll.

Discharged cooling air can confain

k&@&d

poisonous exhaust gases which

present the hazard of severe personalinjury or death.

use

Never

discharged cooling air for heating the

coach interior.

The generator compartment air inlet is sized (see Section

2

SPECIFICATIONS) to allow the required flow rate of air. The air inlet opening and the air discharge opening must be kept free tions to avoid restricting airflow. Dirt, dust, or other debris that may clog the air duct openings should be

removed during periodic maintenance. Dirt might also become lodged between the cooling fins on the engine block and cylinder heads. If this happens,

of

any obstruc-

CS-1274

-

FIGURE

6-4.

COOLING

SYSTEM

6-7

1.

Redistribution or publication of this document by any means, is strictly prohibited.

Remove the capscrews that secure the noise shield (see Figure 6-4) to the engine and lift

off

the noise shield.

2.

Remove the three nuts (located along the lower edge of the scroll) that fasten the flywheel guard to the scroll.

Remove the capscrews that fasten the scroll to

3.

the backplate and lift away from the scroll. Remove the screws that fasten the cylinder air

4. housings to the backplate and cylinder heads and lift off the air housings.

Loosen the flywheel capscrew and back it out

5.

several turns. Attach puller tool to the flywheel as shown in

6.

Figure 6-5. The tool has two jack screws that fit into the tapped holes in the flywheel.

Tighten the puller center screw until the flywheel

7.

comes loose. Remove the puller, flywheel center screw, and washer. Inspect the flywheel and replace

Remove the lead from the low oil pressure cut-off

8.

it

if any air vanes are missing.

switch. Remove the exhaust manifold as described in the

9.

Exhaust System section. Remove the capscrews that secure the backplate

10.

to the engine and lift off the backplate.

Use a brush or low pressure compressed air to

11.

remove any dirt or debris that may be lodged on

the engine cooling fins.

Assembly:

Cooling system assembly is the reverse of disassembly. When installing the flywheel, align the keyway in the flywheel with the woodruff key on the

crankshaft. Use non-hardening sealer on the flywheel capscrew threads and tighten to the specified

torque. Refer to Exhaust System in this section when

installing the exhaust manifold, muffler, and tailpipe.

-1

never operate the generator set with any

Overheating can result in engine

To

damage.

avoid overheating,

of

the cool-

ing system components removed.

IGNITION

SYSTEM

The ignition system consists of the breaker points,

condenser, ignition coil, spark plugs, and wiring. For

reliable generator set operation, the complete ignition system must be in good working order and properly adjusted. Many generator set “problems” can be traced to an improperly maintained ignition system.

Refer to the following sections when servicing or

making adjustments.

Breaker Points and Condenser

The breaker points and condenser mount on top of theengine block. Asmall plunger rides on an ignition cam at the end of the camshaft. The plunger actuates the points which can open and close twice with every

revolution of the camshaft. Point opening is determined by the point gap setting. The exact timing of the ignition spark is dependent on when the points open.

It

is important that the breaker points have the correct gap for easy starting, efficient operation, full power, and proper cooling. A retarded ignition will reduce efficiency while an advanced ignition will cause overheatina.

The condenser extends point life by preventing arc-

ing across the opening breaker points.

A

defective condenser causes a weak spark and rapid point wear. Replace the condenser if defects are suspected.

A

new condenser is supplied with the engine tune-up

kit.

FLYWHEEL

CAPSCREW

FIGURE

FLYWHEEL

‘

6-5.

FLYWHEEL PULLER

FLYWHEEL

PULLER

cs-1000

Breaker

Point

Replacement and Adjustment:

the breaker points at the interval specified in the

Operators Manual and replace if pitted or burned. Filing of the points is not recommended. Use the

following procedure to replace and adjust the points.

The ignition adjustmentsshouid be made with the engine in a static

condition and cold.

1.

Disconnect the negative

(-)

battery cable at the

battery terminal.

2.

Remove the breaker box cover clip and breaker box cover.

3.

Remove the spark plugs to permit easy rotation of

the engine and generator assembly. Using a hex-

head socket and socket wrench, turn the rotor

through-bolt in a clockwise direction until the

breaker point gap is open the maximum amount.

4. Remove the condenser mounting screw (screw

A)

and disconnect the condenser and ignition

lead wires (screw

6-6).

ure

B).

Lift

out condenser (see Fig-

6-8

Inspect

lift

off the

.

Redistribution or publication of this document by any means, is strictly prohibited.

5.

Remove the breaker

points

mounting screws

(screw C) and lift out the point assembly.

C

FIGURE

6.

Replace the condenser and point assembly and

6-6.

BREAKER POINTS

install in reverse order of removal.

Use an allen head wrench to adjust set screw

7.

obtain the gap setting specified in section Specifications. Measure the point gap with a flat thickness gauge (see Figure

6-6).

Clean points

after adjusting.

Make sure feeler gauge

dirt.

is

clean and free

of

any grease,

The timing is adjusted during initial engine assembly and is fixed by the point gap adjustment.

No

other adjustment

or

alignment is

necessary. Replace the point box cover, spark plugs and

8.

spark plug leads.

9.

Connect negative

(-)

battery cable to negative

battery terminal.

ES-1529

D

to

2,

oil

or

SECONDARY

WINDING

PRIMARY

WINDING

-

FIGURE 6-7.

Ignition coils do not normally require any service other than to keep all terminals and connections clean and secure.

Also, punctures, and other mechanical damage. If poor ignition performance

components are not at fault, the coil can be tested with the specified procedures. When replacing the coil, observe proper polarity, The negative nal connects

(+)

terminal connects to a battery

to

the breaker points and the negative

the control.

Ignition

A

quick test

Coil

Testing

of

coil output can be made by checking the ignition spark. Remove one of the spark plugs. Reconnect the spark plug wire to the spark plug. Ground the spark plug to bare engine metal and crank the engine. between the plug center electrode and side elec-

trode.

If

the spark is weak, the coil, points and con-

denser,

Direct

or

wiring is probably defective.

Testing

With

remove all the wires connected to

to the terminals, the coil may be removed from the engine. Use the following procedure to test.

IGNITION

COIL

check for looseseams, dents,

is

evident and other ignition

(-)

(B+)

source within

A

good spark should be observed

OhmmetecTo

test a coil directly,

it.

For easier access

ES-1329

termi-

lgntion

Coil

The ignition coil is a transformer that steps up the

battery voltage to about

firing. The coil

is

composed of a primary winding, secondary winding, sealing compound, bakelight cap, and the outside case and necessary terminals

(Figure

6-7).

20,000

volts for spark plug

6-9

1.

Inspect terminals for corrosion, looseness, cracks, dents

or

other damage. Look forevidence of electrical leakage around high tension terminals (indicated by carbon runners). Damaged leaking coils should be replaced.

2.

Clean the outside

of

the coil with a cloth dam-

pened in parts cleaning solvent.

or

3.

Redistribution or publication of this document by any means, is strictly prohibited.

To measure resistance in the primary circuit, connect one ohmmeter lead to the positive terminal and the other to the negative on the coil. The resistance should be between

3.87

and

4.73

ohms. A high resistance value indicates an open circuit or poor connection inside the coil, and the coil should be replaced.

4.

To

measure resistance in the secondary circuit, connect the ohmmeter leads to the two high tension terminals (see Figure measured should be between

A

ohms. shorted secondary winding.

value indicates the coil has excessive internal

resistance or an open circuit. Replace coil if not

within specifications.

lower resistance value indicates a

-

6-8).

12,600

A

OHMMETER

(-)

terminal

The resistance

and 15,400

high resistance

(+)

Chipped Insulator - Check for advanced timing. Bend only side electrode when setting gap.

Splash Fouled - Check for accumulated com-

bustion chamber deposits. See Cylinder Head in

Section

LightTan or Grey Deposits- Normal plug color.

Replace spark plugs that show signs of fouling for electrode erosion, with spark plugs of the recommended type. See Figure method of checking plug gap.

6.

6-9

on

recommended

ES-1374

ES-1373

FIGURE

Spark

Remove

recommended in the Operators Manual. A careful examination of the plug can often pinpointthesource of an engine problem. The following covers some

Plugs

and

common

cause.

One Plug Carbon Fouled - Check for an open

ignition cable or low compression.

Black Soot Deposits - Check for faulty choke operation, overly rich fuel mixture, or dirty air

filter. Oil Fouled - Check for faulty crankcase

breather, worn rings, or worn valve guides. Burned or Overheated - Check for leaking

intake manifold gaskets, lean fuel mixture, or incorrect ignition timing. Be sure plug is not in

-

wrong heat range.

inspect

spark

6-8.

TESTING COIL SECONDARY

the

spark Plugs

plug

conditions

and

at

the

intervals

probable

FIGURE

6-9.

CHECKING PLUG GAP

Wiring

Ignition system wiring includes (1) One positive

wire which carries the low voltage current from the

battery to the primary winding of the coil. negative

points and condenser. that carry the high voltage current from the secondary winding of the coil to the spark plugs. The spark

plugs and coil secondary are all grounded to the enghe making a completecircuit foFthevoltage back to the battery. The ignition coil primary (low voltage side) is grounded when the breaker points close.

Check and cuts or breaks in the insulation. Clean all termi-

nals and connections and test for continuity with an ohmmeter. Use a megger spark plug wire insulation.

(-)

wire which carries low voltage to the

(3)

Two high tension wires

all

low

voltage

wiring

for

loose

to

check for breaks in the

connections

(2)

(e+)

One

CRANKCASE VENTILATION SYSTEM

The crankcase breather prevents pressure from

building up in the crankcase. It also prevents oil con-

tamination by removing moisture or gasoline vapors

and other harmful blow-by materials from the crankcase. These vapors are routed to the carburetor

where they are mixed with incoming airand burned in the combustion chamber. cause oil leaks, high oil compression, rough idle,

reduced engine power and a rapid formation of

sludge and varnish within the engine.

A

sticky breather valve can

6-1

0

Crankcase Breather Service

Redistribution or publication of this document by any means, is strictly prohibited.

If

the crankcase becomes pressurized as evidenced

by oil leaks at the seals, use the following procedures

to

service.

Remove the breather tube from the valve cover (see

Figure washer, reed valve, and breather baffle. Clean all parts in parts cleaning solvent.

personal injury

facturers recommendations when cleaning parts.

6-10).

Remove the valve cover, pack, spring

Most parts cleaning solvents are

flammable and can cause severe

if

used improperly. Follow the manu-

HEX

HEAD

CAPSCREW

FLAT

U

frequency.

enginespeed under changing load conditionsso that generator voltage and frequency do not vary.

Governor

Before making governor adjustments, run the unit about operating temperature. If governor of adjustment, make a preliminary adjustment at no

load to first attain a safe voltage and speed operating range.

An accurate voltmeter and frequency meter should be connected to the generator in order to correctly adjust the governor. A small speed drop not noticeable without instruments will result in an objectionable

voltage drop.

A

binding in the bearings ball joint, or in the carburetor throttle assembly will cause erratic governor action or alternate increase and decrease in speed (hunting). A lean carburetor adjustment can also cause hunting. Springs tend to lose their calibrated tension through fatigue after long usage.

The

governor

maintains

a

constant

Adjustments

10

minutes under light load to reach normal

is

completely out

of

thegovernorshaft, in the

PACK

I¶

.+

FLAT

C-1101

+.

The reed valve must be flat with no sign of a crease. Assemble using a new gasket. overtighten valve cover capscrew.

Reed valve must be assembled as shown with washer and breather baffle on the bottom.

-1

enter the engine. Be careful not to distorf the valve cover when tightening.

FIGURE

6-10.

CRANKCASE BREATHER

Do

not

on

top

Over tightening the valve cover can cause an air leak and allow

dirt

to

GOVERNOR

The governor controls engine speed which directly affects the voltage output and frequency of the generator. An increase in enginezipeed will cause a

in

corresponding increase

A

quency. corresponding decrease in generator voltage and

decrease in engine speed will cause a

generator voltage and fre-

If

the governor action is erratic after all adjustments are made, replace the spring. operation, the problem is probably within the gover-

nor mechanism. Refer to Governor Cup Section

service procedures. Adjustments to the governor should be made in the

following sequence.

1.

The carburetor fuel mixture screws must be cor-

rectly adjusted before governor adjustments are made. If the carburetor needs adjusting, refer to Mixturescrew Adjustments in this section before

making any adjustments to the governor.

Touching hot exhaust pipes or

IBWAR"G/

severe personal injury. Use extreme caution

when making adjustments while the engine is

running.

2.

Adjust the length of the governor linkage and

check for bindina or excessive looseness. The length of the liniage connecting the governor arm to the throttle shaft assembly is adjusted by loosening the lock nut and rotating the ball joint (see Figure

the engine stopped and tension on the governor

spring, the stop on the throttle shaft assembly almost touches the stop on the side of the carburetor. (One more turn of the governor ball joint

would allow the throttle shaft stop to touch the

carburetor.) Tighten lock nut.

3.

With the warmed up unit operating no

adjust the speed adjustment nut to obtain

and

127.5

(~k4.5)

moving parts can result

6-11).

Adjust this length

volts for frequency and voltage.

If

this does not improve

9

so

that with

no

load,

62

hertz

for

in

6-1

1

4.

Redistribution or publication of this document by any means, is strictly prohibited.

Check the frequency and voltage first with a load applied and then with no load applied. The frequency and voltage should stay within the limits shown in Table 6-1.

6.

Recheck the speed setting made in step readjust if necessary.

7. Set thecarburetor throttlestop screw as specified in the Fuel System section.

#3

and

TABLE

VOLTAGE AND SPEED

VOLTAGE CHART

FOR

CHECKING

GOVERNOR

No-Load Voltage

Full-Load Voltage

SPEED CHART

GOVERNOR

Maximum No-Load Speed (Rpm) 1890

Hertz (Frequency) 63

Minimum Full-Load Speed 1770

5.

Adjust the governor sensitivity to give the closest regulation (least speed and voltage difference between hunting condition. regulation), turn the sensitivity adjustment screw counterclockwise. To decrease sensitivity, turn

the sensitivity adjustment screw clockwise.

REGULATION

Maximum 132

Minimum 108

(Rpm) Hertz 57

no

load and full load) without causing a

6-1.

CHARTS

1

PHASE

2

WIRE

FOR

CHECKING

REGULATION

To

increase sensitivity (closer

FUEL

The fuel system must be in good condition and properly adjusted for efficient generator set operation. The main components of the fuel system are the air cleaner assembly, carburetor, choke, intake manifold, fuel filter, fuel pump, and air preheater. When servicing, disassemble, assemble, and adjust as spec-

ified in the following sections.

Air Filter Assembly

The air filter assembly consists of the air cleaner housing, air filter, air cleaner adapter, and choke assembly (See Figure 6-12).

Disassembly:

remove and disassemble the air filter assembly.

1. Remove the crankcase breather hose and air preheater hose from the air cleaner housing.

2. Remove the air cleaner housing center capscrew and lift off the housing and air filter.

3. Remove the choke cover retaining nut and lift off

the choke cover.

4.

Disconnect the choke lead wires at the choke

terminals.

5.

Remove the three capscrews that secure the air

cleaner adapter to the carburetor and lift off the

adapter. Note that choke linkage must be disengaged from choke assembly as adapter is removed.

6. Remove the two capscrews that secure choke bracket to adapter and lift off choke assembly.

SYSTEM

Use the following procedures to

-

GASOLINE

-

SPEED ADJUSTMENT NUT

-

SENSITIVITY

FIGURE

6-11.

ADJUSTMENT

GOVERNOR ADJUSTMENTS

SCREW

FS-1613

Asseddy:

gasket between adapter and carburetor.

Carburetor and Intake Manifold Assembly

The carburetor and intake manifold assembly con-

sists of the intake manifold, choke pull-off assembly, air preheaters, and carburetor (See Figure 6-13).

Disassembly:

remove and disassemble the carburetor and intake manifold assembly.

1. Removetheair filterassembly asdescribed in Air Filter Assembly in this section.

2. Disconnect the fuel line and governor control linkage from the carburetor.

3. Remove the intake manifold capscrews and lift off the carburetor air preheater. Lift off the carburetor and intake manifold as an assembly.

Reverse order of disassembly. Use a new

Use the following procedures to

CRANKCASE

Redistribution or publication of this document by any means, is strictly prohibited.

TUBE

BREATHER

AIR

BREATHER

HOSE

CARBURETOR

4.

Remove the two intake manifold gaskets and plug the intake ports with a rag to prevent loose parts

from accidentally entering ports.

5.

Remove the two capscrews that secure the carburetor and choke pull-off assembly to the intake manifold. Disengage the choke pull-off linkage

from the carburetor and carefully separate the

carburetor from the intake manifold.

I

FIGURE

6-12.

AIR

CLEANER

CHOKE COVER

FILTER

ASSEMBLY

adjustment screws. Significant variation from the correct settings may result in serious engine trouble.

An overly rich mixture not only wastes fuel, but can

increase engine wear by washing the lubricant from the cylinder walls and diluting the crankcase oil. An overly lean mixture results in a spots in acceleration and a greater tendency to burn valves and spark plugs.

loss

of power, flat

FS-1609

.

Assembly: Reverse order gaskets befween intake manifold and engine

between intake manifold and carburetor. any sealer screws

on

gaskets. Tighten intake manifold cap-

to

specified torque.

Carburetor Mixture Screw Adjustments

The most common cause satisfactory adjustment

of

disassembly. Use new

Do

not use

of

poor carburetion is un-

of

the idle or main mixture

and

Mixture screw adjustment should be checked with every engine tune-up and whenever a carburetion

problem is suspected. Before adjusting, be sure the

ignition system is working properlyand the governor

is correctly set. If the carburetor is totally out of adiustment, use the mixture settinas aiven in Table

6-2

as preliminary adjustments. fur: the mixture screws in until lightly seated, then turn out the specified number of turns.

6-1

3

CHOKE PULL-OFF

Redistribution or publication of this document by any means, is strictly prohibited.

n

AIR~PREHEATER

\\\

INTAKE MANIFOLD

FIGURE 6-13.

\

CARBURETOR

db-1

91

i

\,a

GOVERNOR CONTROL LINKAGE

AND

INTAKE

MANIFOLD

\\

‘1

ASSEMBLY

FUEL LINE

FS-1607

Forcing the mixture adjustment

@%&%I

and seat. Turn in only

Start the engine and allow it to run for about 10 minUtes. Refer to Figure 6-14 for location of the adjustment screws. Use the following procedure to adjust:

FIGURE

6-14.

screws fight

MIXTURE

wi//

damage the needle

until

light tension can be felt.

IDLE

ADJUSTMENT

SCREW

ADJUSTMENT

SCREWS

THROTTLE

STOP

SCREW

MAIN

ADJUSTMENT

SCREW

FS-1608

-

GASOLINE

1.

Stop the set and connect a voltmeter, frequency

meter, and load bank to the generator output leads.

2.

Start the generator set and applyafull load. Verify that the frequency adjust the governor speed adjustment nut if necessary to obtain required frequency.

3.

Turn the main adjustment screw inward until voltage or frequency drop again. Locate the point where the voltage and frequency are highest. From this setting turn the main adjustment screw out an additional 1/4 turn.

4. Remove the load and verify that frequency is within adjustment nut if necessary to obtain required frequency.

5.

Turn the idle adjustment screw inward until volt-

age and frequency dropand engine begins to run rough or starts hunting. Back out idle adjustment screw as required for smoothest operation without hunting.

6.

Pull the governor linkage toward the front of the set resting against the throttle stop screw. Adjust the

stop screw to obtain a setting

(k

7.

Release the governor linkage and observe the stability

62

k

so

that the throttle lever on the carburetor is

4.5) volts.

of

the set. Set the voltage and frequency

is

within

1

hertz. Adjust governor speed

59 k 2

of

55

hertz and 100

hertz and

6-1

4

TABLE

Redistribution or publication of this document by any means, is strictly prohibited.

6-2.

CARBURETOR ADJUSTMENT SPECIFICATIONS

MIXTURE

MODEL

NHE

and adjust the sensitivity

of

the governor as specified in the Governor section. Add and remove a full load several times to make certain the set does not bog down

Carburetor

Overhaul

or

hunt.

Carburetion problems not corrected by mixture

float adjustments are usually a result of gummed-up

or

fuel passages

worn internal parts. The most effec-

tive solution is a complete carburetor overhaul.

In general, overhauling acarburetor consists of complete disassembly, a thorough cleaning, and replacement of worn parts. Carburetor repair kits are available that supply new gaskets and replacements

for those parts most subject to wear.

General instructionsfor overhauling a carburetor are

given below. Carefully note the position of all parts while removing to assure correct placement when

reassembling. Read through all the instructions before beginning

for

a better understanding of the procedures involved. Carburetor components are shown in Figure

6-15.

CHOKESHAFT ADJUSTMENT

I

IDLE

SCREW

IDLE

1

f1/4

or

SETTINGS

MAIN

2 f 1/4

1.

Remove the air cleaner adapter and the automatic

choke assembly.

2.

Remove throttle and choke plate retaining screws, then plates. Pull out throttle and choke shafts, being careful not to damage the teflon coating applied to some throttle shafts.

3.

Remove main and idle mixturescrew assemblies.

4.

Separate the lower section of thecarburetor (fuel

bowl) from the upper section (fuel bowl cover) of the carburetor.

5.

Carefully note position of float assembly parts, then slide out retaining pin and remove the float assembly, any springs valve.

6.

Unscrew and remove needle valve seat.

Clean and Repair;

disassembled, clean and repair using the following procedure.

1.

Soak all metal components not replaced by repair

kit in carburetor cleaner. floats cleaner manufacturer’s recommendations.

-1’:

1

severe personal injury

the manufacturers recommendations when cleaning parts.

FLOAT*

LEVEL

1/16

t

1/32

in.

(1.6

f

0.8

mm)

or

clips, and the needle

When the carburetor is completely

Do

not soak non-metal

or

other non-metal parts. Follow the

Most parts cleaning solvents

I

are flammable and can cause

if

used improperly. Follow

FLOA1

MAIN ADJUSTMENT

SCREW

ASSEMBLY

FIGURE

6-15.

CARBURETOR

2.

Clean all carbon from the carburetor bore, especially where the throttle choke plates seat. Be careful not to plug the idle or main fuel parts.

3.

Blow out all passages with compressed air. Avoid

using wire

or

other objects

for

cleaning that might

increase the size of critical passages.

4.

Check the condition of any needle valve not

included in repair kit and replace if damaged

SPRING

(Figure damaged.

5.

Check the choke and throttle shafts for excessive

6-16).

Replace float if loaded with fuel

or

play in their bore and replace if necessary.

6.

@

\

XFS-1604

OVERHAUL - GASOLINE

Replace old components with new parts included

in repair kit.

Reassembly and Installation:

When the carburetor

parts are clean and dry, reassemble using thefollow-

ing procedure.

6-1 5

Slide in throttle shaft and install throttle plate

Redistribution or publication of this document by any means, is strictly prohibited.

1. using new screws, if furnished in repair kit. Before

tightening the screws, the plate must be centered

To

do

so,

in the bore.

back off the throttle stop screw as necessary and completely close the throttle lever. Seat the plate by gently tapping with a small screwdriver, then tighten screws.

Install the choke shaft and plate in the same manner.

specified in Table 6-2. If the setting is incorrect, remove float and bend tab to adjust. Bend the

float only at the point indicated.

Attempting adjustments with

k&%!!@l

the

floaf

assembly installed can damage the inlet need/e and seat. Remove float assembly before making adjustments.

BEND TAB

FIGURE 6-16.

MIXTURE

NEEDLE INSPECTION - GASOLINE

Install idle mixture screw assembly. Turn in screw until lightly seated and then out the number of turns specified in Table 6-2.

Forcing the mixture adjustmenf

screws tight will damage the needle and seat Turn in only untillight tension felt.

Install needle valveand seat, fuel bowl gasket and float assembly. Make sure that all clips and springs are properly placed and that the float

moves freely without binding. See Figure 6-17.

POSITION

HOOK

NDER TANG ON

POSITION OF SPRING

AFTER INSTALLATION

FIGURE 6-17. FLOAT INSTALLATION

,AL

Invert the float and needle valve assembly and

check float level by measuring between the float and gasket at the point shown in Figure 6-18.The full weight of the float should be resting on the

needle valve and spring. The correct distance is

FS-1483

is

FS-1610

*I+--

BOWL FLANGE

GASKET

FIGURE 6-18. FLOAT LEVEL

Install float bowl and main mixture screw assembly. Turn screw in until lightly seated and then turn out the number of turns specified in Table

6-2.

Forcing the mixture adjustmefit

screws tight will damage the needle and seat. Turn in only until light tension can be felt.

When carburetor is installed on set, make final

adjustments to mixture screws as described in Carburetor Mixture Screw Adjustments section.

Choke

The choke consists of a bi-metal, spiral strip, electric

heating element, and choke pull-off diaphragm. The bi-metal coil is connected to the choke shaft and holds the choke plate nearly closed when the engine is cold. When the engine starts, vacuum from the intake manifold causes the pulloff diaphragm to pull in and partially open the choke.

tinues to run, electric current is supplied to the heat-

ing element. Heat from the element causes the bi-

metal strip to coil. The coiling action of the bi-metal strip turns the choke shaft and gradually opens the choke plate. Heat from the element keeps the choke open while the engine is running.

The choke gets normal operation and can cause

severe burns if touched.

Do

while fhe set is operating.

\L

'

TAB CONTACTING

OF

HEAD

FULL WEIGHT OF FLOAT

COMPRESSING INLET

PIN, WITH

VALVE SPRING

As

the engine con-

very

hot during

FS-1611

nof remove choke cover

t

6-1

6

PLASTIC

Redistribution or publication of this document by any means, is strictly prohibited.

COVER

XFS-1605

FIGURE

6-19.

If the engine starts but runs roughly and blows out

or

black smoke after a minute choke is set too rich.

If

the engine starts but sputters

or stops before it warms up, the choke

Choke

Adjustment:

Table 6-3 lists the choke settings

two of operation, the

is

set too lean.

for various ambient temperatures. Stop the set and allow

it

to

cool down before making adjustments. Use

TABLE

CHOKE

Ambient Air

Temperature

6-3.

ADJUSTMENTS

Rotation From

Reference Mark*

(Fully Closed)

40" F

(4"

C)

45"

F

(7"

C)

50°F (10°C)

55°F

(13°C)

60°F (16°C)

650~

(18°C)

70°F (21°C)

75"

F (24" C)

80"

F (27" C) a50 F (290 c) 90" F (32°C)

950

F

(35" C)

F

(38°C)

100"

OD

4"

cw

8"

CW

12"

cw

16" CW

20"

cw

24" CW 27" CW 32" CW

35"

cw

39"

cw

43"

cw

47"

cw

CHOKE

ASSEMBLY

the following procedures to adjust.

1.

Remove the protective plastic choke cover (see Figure 6-19) and loosen the heating element

cover screws.

2. Rotate heating element until choke plate is about halfway open.

3.

Slowly rotate cover counterclockwise

(CCW)

while tapping thecarburetor choke lever and making the choke lever bounce. Continue rotation until tapping the choke lever no longer makes bounce. This

is

the fully-closed position and

becomes the reference position.

O~~TER

TAB

FS-1606

it

*Each mark on choke hou

angular rotation.

ng equals

5"

6-1

7

FIGURE

6-20.

BI-METAL SPIRAL

STRIP

Refer to Table 6-3 to determine the number of

Redistribution or publication of this document by any means, is strictly prohibited.

degrees element cover must be rotated (clockwise) from reference position. Marks on choke housing are spaced at

Rotate element cover asspecified and then tighten cover mounting screws.

Move choke lever back and forth to check for smooth operation. Lever should return automatically to the free position when released from the open position without sticking or binding.

Install plastic choke cover and tighten center

mounting nut.

ChokeReplacement:

the protective plastic cover and check to see heating element is working. The heating element cover should become hot after a few minutes of operation. If the element cover does not get hot, start the set and then use an AC voltmeter to check for voltage (approx-

imately 20 VAC) at the element cover terminals. voltage is not present, check for opens or shorts in the control wiring.

If

the voltage is present at the heating element cover terminals, stop the set and remove the heating element cover. Inspect the heating element and replace

burned out or broken.

strip and replace if damaged, deteriorated, or dragging

in the housing.

When installing a new bi-metal strip, maintain the original direction of spiral (see Figure 6-20). The outer tab must point in a clockwise direction. Make sure the coil sets squarely in the housing and the inner end of the coil engages the slot in the choke shaft. When installing the element cover, make sure the slotted tang on the cover engages the bi-metal strip.

5"

intervals.

If

the choke fails to open, remove

if

Also

inspect the bi-metal spiral

CHOKE LEVER

/-CHOKE

PLATE

CLOSED

the

If

if

.GM

Choke Pulloff Diaphragm Adjustments:

pull-off diaphragm partially opens the choke plate following engine startup. This helps prevent flooding and provides for smoother engine operation as the set is warming up. Use the following procedure to adjust.

1.

Remove the complete air filter assembly as specified in the air Filter Assembly in this section to provide access to the choke plate.

2.

Disconnect diaphragm hose from intake manifold

4

to

18

and apply vacuum to the diaphragm.

Apply light finger pressure against the choke

3.

lever to take up all freeplay in the pulloff linkage (see Figure 6-21).

4.

Check alignment (as viewed from the top) of

diaphragm stem, pulloff linkage, and slot in choke lever. Correct alignment as required.

5.

Measure distance between choke plate and bottom of carburetor at the point indicated in Figure 6-21. If necessary, bend diaphragm mounting

bracket to obtain 0.39 to 0.43 inches (9.9 to 10.9 mm) clearance.

6. Move choke lever back and forth to check for free movement. Verify that choke does not bind or

stick.

7.

Remove vacuum supply from diaphragm and

install filter assembly on carburetor.

Fuel

Pump

All

gasoline fueled generator sets are equipped with an

electric fuel pump.

off

valve that prevents fuel flow to the carburetor when

the set is not in operation.

insufficient fuel delivery is suspected, use the appropriate following procedure

Pump.

Do

[BWARNINGI

Onan supplied electric pumps. The output pressure is much higher and can cause carburetor flooding leakage, creating a fire hazard.

electric fuel pumps for standard

inches (102 to 457 mm) Hg

All

fuel pumps have an integral shut-

If

the pump malfunctions or

to

test, and repairheplace the

not substitute automotive type

The choke

or

fuel

L=J-

FIGURE

6-21.

CHOKE

PULL-OFF DIAPHRAGM

ENDHERE

FS-1603

1986

Pump Test (for units built June

the fuel pump by checking the pump outlet pressure.

Use the following procedure.

1. Remove the fuel line from the pump outlet and install a pressure gauge.

2.

Press the START switch and

seconds until pressure reading is constant.

3.

The pressure reading for a good pump should fall

5

psi

(27.5

within 4 to should stay constant or drop

A

low

pressure reading with little or no pressure drop indicates a weak or broken diaphragm or diaphragm spring, worn linkage or leakycheckvalves. above maximum, the pump diaphragm is too tight or the diaphragm (or plunger) return spring of the above conditions are cause for repair or replacement of the pump.

6-1

8

to 34.4 kPa). The pressure

and before):

hold it for several

off

very slowly.

If

is

too

strong.

Test

pressure is

Any

Fuel

Redistribution or publication of this document by any means, is strictly prohibited.

Pump

bef0re):Service

cover, plunger tube, and plunger assembly.

the

electric

atmosphere occurs, replace the pump.

JACAUTIONI

fhe side

surrounds

components are not serviceable.

Repair

system

and

of

fhe pump as if refains the dry gas which the elecfricai system. Electrical sysfem

(for

units

of

the fuel pump is limited

are

hermetically

are

not

serviceable.

Do

not

center

of

built

tamper

with

the

mounting bracket on

June

to

sealed

If

electrical

the

1986

and

the bottom

All

parts of

in

a

gas

failure

seal

at

the

PUMP

ASSEMBLY

PLUNGER

RETURN

SPRING

Use the following procedure for servicing the pump:

1. Using a gas pliers, loosen the pump cover, then remove by hand.

Remove the magnet and cover gasket (Figure 6-22).

PUMP

ASSEMBLY

I

6.

7.

Pump

fuel pump by checking the pump outlet pressure. Use the following procedure.

1.

FS-1487

FIGURE 6-22. FUEL PUMP ASSEMBLY

(June

1986

and

before)

Using a thin nose pliers, remove the retainer spring from the plunger tube. Remove the washer, and plunger from tube (Figure

Wash all parts (except gasket and seal) in parts cleaning solvent. Blow out solvent and dirt with

low pressure compressed air. Slosh the pump assembly in cleaning solvent, blow dry and swab the inside of the plunger tube with a cloth wrapped around a stick. If the plunger does not wash clean or has rough spots, gently clean the surface with crocus cloth.

-1

severe personal injury the manufaciurers recommendations when cleaning parts.

5.

Insert plunger in tube, buffer spring end first.

Check fit by slowly sliding the plunger back and forth in the tube. It should move fully without any tendency to stick. If a click cannot be heard as the

plunger internal pump assembly is not functioning prop-

.-

erly and the pump should be replaced.

“0”

ring seal, cup valve, plunger spring

6-23).

Most

parts

cleaning solvents

are flammable and can cause

if

used improperly. Follow

is

slid from one end to the other, the

-

a pressure gauge.

2.

Press the START switch and hold it for several seconds until pressure reading

3.

The pressure reading for a good pump should fall within shouid stay constant or drop

The fuel system must be in good condition and properly maintained for eff icient generator set operation. The main components of the fuel system are the air cleaner assembly, carburetor, intake manifold, fuel filter, solenoid valve, vaporizer, and two-stage regulator.

All

al system and are intended gas fuel supply tanks. The LP-gas fuel supply tank

must be designed with a dip tube to permit liquid fuel withdrawal. The following sections provide basic information about LP-gas fuel systems and specific service procedures for each fuel system component.

FIGURE

Install plunger spring, cup valve, and washer. Compress the spring and install the retainer with ends in the side holes

Check cover gasket and replace if deteriorated. Place cover gasket in the bottom cover and install cover assembly on pump. Twist cover on by hand and tighten securely with a 5/8-inch wrench,

Test

(for

Removethefuel line from the pump outlet and install

3-1

If

pressure reading is below

replace fuel pump. If

pressure reading is at zero, stop engine cranking and check electrical connections. Press the START switch and recheck pressure reading.

There are no serviceable components in the

fuel pump. Replace if defective.

FUEL SYSTEM

LP-gas generator sets utilize a liquid withdraw-

units

/2

to 5 psi

6-23.

PLUNGER ASSEMBLY

built June

(1

7986andaifer):Test the

7.2

to

34.4

-

to

share the vehicle LP-

“0”

of

is

constant.

kPa). The pressure

off

very slowly.

3-1

12

psi

LP-GAS

Fs-1486

ring seal

the tube.

(17.2

kPa),

‘6-1

9

LP-Gas Fuel Systems

Redistribution or publication of this document by any means, is strictly prohibited.

LP-gas liquid withdrawal fuel systems typically oper-

200

ate at pressures that range as high as kPa) when the ambient temperature is

psi (1379

110°F

(43.3"C). Because of the high pressures, special precautions must be taken to avoid releasing largequantities of highly flammable LP-gas when servicing the

fuel system. Use the following procedure to purge the fuel system of LP-gas before servicing any fuel system components.

LP-Gas Purging Procedure:

To

purge the LP-gas from the set fuel system, close the shut-off valve at the fuel tank and then start the generator set. Allow

to

the generator set

operate until

Crank the set a few times after

it

runs

out

of

it

stops to make sure

fuel.

the fuel system is completely purged of all LP-gas fuel.

If the generator set cannot be operated, move the

RV

coach to an outdoor location that is well ventilated and is away from fire or flame. Disconnect both the vehicle negative set negative

(-)

battery cable and the generator

(-)

battery cable from their respective

battery terminals. Close the fuel shutoff valves at the

fuel tank for both the generator set fuel supply system and the appliance (stove, heater, etc.) fuel supply system. In addition, close the fuel shutoff valves at each appliance.

Fuel presenfs fhe hazard of fire or

IBWARNING]

personalinjury nate all possible sources lights

or

sparking electrical equipment before purg-

explosion which can cause severe

or

deafh

if

accidentally ignited.

of

ignition such as pilot

Ellmi-

ing LP-gas from the fuel system. Provide adequafe venfilafion

fo

dissipafe LP-gas

as

if

is

released.

Slightlyopen the fuel line (flexiblesection) at thesolenoid valve just enough to allow the LP-gas to slowfy

escape. Don't open the fitting too much or a large

quantity of gas will be released. Disconnect the fuel supply hose from the carburetor

and hold

it

clear of the set. Press in and hold the primer

button on the regulator to release LP-gas from the set fuel system. When no more gas can be heard escaping from the open end of the fuel supply hose, reconnect the hose to the carburetor and proceed to the approp-

riate component service station.

Carburetor, Air Filter, and Intake Manifold Assembly

Thecarburetor, air filter, and intake manifold assembly

consists of the air cleaner housing, air filter, air cleaner

adapter,

manifold (see Figure

Disassembly:

K5

relay assembly, carburetor, and intake

6-24).

Use the following procedures

to

remove and disassemble the carburetor, air filter, and intake manifold assembly.

1.

Remove the crankcase breather hose from the air cleaner housing.

2.

Remove the air cleaner housing center capscrew

and lift off the housing and air filter.

CARBURETOR

INTAKE MANIFOLD

FIGURE

6-24.

CARBURETOR, AIR FILTER,

6-20

AND

INTAKE MANIFOLD ASSEMBLY

AIR CLEANER HOUSING

XFS-1612

3.

Redistribution or publication of this document by any means, is strictly prohibited.

Disconnect the lead wires from the

K5

relay

terminals.

4.

Remove the three capscrews that secure the air cleaner adapter to the carburetor and lift off the adapter.

5.

Remove the two capscrews that secure the relay bracket

to

the adapter and lift off the relay

K5

assembly.

6.

Disconnect the fuel hose and governor control

linkage from the carburetor.

7.

Remove the two capscrews that secure the carburetor to the intake manifold and lift off the carburetor.

8.

Use the following procedures if

it

is necessary to

remove the intake manifold.

A. Disconnect the flexible fuel supply line from

the fuel vaporizer.

B.

Remove the exhaust manifold as described in EXHAUST SYSTEM in this section to provide

off

clearance for lifting

the intake manifold.

Bending the fuel vaporizer fubing will weaken fhe mefa/

which might cause cracks

bend fhe vaporizer tubing

fo

form.

to

remove the

Do

not

infake manifold.

C.

Remove the intake manifold capscrewsand lift

off

the intake manifold.

D.

Remove the two intake manifold gaskets from the block and plug the intake ports with rags to prevent loose parts from accidentally entering

the ports.

Assembly:

Reverse order of disassembly. Use new gaskets between the exhaust manifold and engine, the intake manifold and engine, and carburetor and intake manifold. Tighten exhaust and intake manifold cap-

screws to specified torque. Tighten fuel vaporizer fittings and check for leaks.

Carburetor Mixture Screw Adjustments

LP-gas carburetors have three adjustment screws that must be properly set for satisfactory operation. The

throttle stop screw controls how much the throttle

plate remains open when the throttle is pulled back to

the closed position. The idle adjustment screw controls the fuel mixture when the set is operating at no

load. The main adjustment screw controls the fuel

mixture when the set is operating at full load.

No

other adjustments are required with an LP-gas carburetor since there are no float or choke adjustments.

Mixture screws should not be adjusted until the ignition system, governor, and other fuel system components have been checked for correct operation.

If

the carburetor is totally out of adjustment, turn the mixture screws in until lightly seated. For a preliminary adjustment turn the main adjustment screw out 2-1/2 turns and the idle adjustment screw out

1

(f1/4)

(k1/4)

turn.

ADJUSTMENT

SCREW

-

LP

4601

GAS

MAIN ADJUSTMENT

FIGURE

6-25.

MIXTURE

SC

ADJUSTMENT

SCREWS

Forcing the mixture adjustment

screws fight wlll damage fhe needle

and seaf.

Starttheengineand allow itto run forabout

Turn

in

on/y until right fension can be fe/f.

10

minutes at light load. Refer to Figure 6-25 for location of the adjustment screws. Use the following procedure to adjust:

1.

Stop the set and connect a voltmeter, frequency meter, and load bank to the generator output leads.

2.

Start the generator set and apply a full load. Verify thatthefrequencyis within59+2 hertzandadjust the governor speed adjustment nut if necessary to obtain required frequency.

3.

Turn the main adjustment screw inward until voltageor frequency drop and then outward until voltage or frequency drop again. Set the main adjustment screw at the point where the voltage and frequency are highest.

4.

Remove the load and verify that frequency is within 62

1

hertz. Adjust governor speed adjustment

if

necessary to obtain required frequency.

nut

5.

Turn the idle adjustment screw inward until volt-

age and frequency drop and engine begins to run rough or starts hunting. Back out idle adjustment screw until engine runs smoothly without hunting.

6. Pull the governor linkage toward the front of the set

so

that the throttle lever on the carburetor is

resting against the throttle stop screw. Adjust the

stop screw to obtain a setting of

(k4.5)

volts.

7.

Release the governor linkage and observe the sta-

55

hertz and 100

bility of the set. Set the voltage and frequency and adjust the sensitivity of the governor as specified under Governor in this section. Add and remove a half load several times to make certain the set does not bog down or hunt.

6-21

Carburetor Overhaul

Redistribution or publication of this document by any means, is strictly prohibited.

Carburetor problems not corrected by mixture adjustments may be caused by dirt in fuel passages or worn

internal parts. Under normal conditions, the carburetor should seldom require cleaning since porizes complete before reaching thecarburetor and

leaves no residue. However, a bad fuel supply or inoperativefuel filter may allow dirt or oil tocollect in the carburetor. This may require that the carburetor be cleaned to restore satisfactory operation.

LP

gas va-

Remove the throttle stop collar and throttle stop

1.

lever from the end Remove the throttle plate retaining screws and

2.

throttle plate. Remove dust seals from throttle

shaft and carefully pull out throttle shaft.

Remove main and idle mixture screw assembly.

3.

Separate lower section (bowl) of carburetor from

4.

the upper section (bowl cover).

of

the throttle shaft.

Overhauling the carburetor includes complete disassembly, thorough cleaning, and replacement of worn parts. Carburetor repair kits are available that supply new gaskets and replacement parts for the components subject to wear.

Note the position to insure correct placement when reassembling.

Refer to Figure

Removal and Disassembly:

from the intake manifold as specified in Carburetor Air Filter, and Intake Manifold Assembly in this section. Use the following procedure to disassemble the carburetor.

k@!@!!l

personal injury facturers recomrnenda fions when cleaning parts.

THROTTLE

STOP

ADJUSTMENT

of

all components while removing

6-26

for component designations.

Remove the carburetor

.

Mosf

parts cleaning solvents are

flammable and can cause severe

if

used improperly. Follow the manu-

SCREW

\

IDLE

ADJUSTMENT

SCREW

Clean and Repair:

disassembled, clean and repair using the following procedures.

1.

Soak all metal components not replaced by repair

kit in carburetor cleaner. metal parts or they may bedamaged by the cleaning solution. Follow the cleaner manufacturer’s recommendations.

2.

Clean all carbon from throttle bore, especially

where the throttle plate seats. Be careful not to

plug the idle or main fuel parts.

3.

Blow out all passages with low pressure

241

kPa) compressed air. other objects for cleaning that might increase the size of critical passages.

4.

Check the condition of the mixture screws (see Figure

5.

Replace all with new parts included in the kit.

Reassembly and Installation:

parts are clean and dry, reassemble using the following procedure.

6-27)

When the carburetor is completely

Do

not soak any non-

(35

Do

not use wire

and replace if worn or damaged.

old

components, seals,

When the carburetor

and

gaskets

psi/

or

THROTTLE

FIGURE

Q

6-26.

CARBURETOR OVERHAUL

THROTTLE

FS-1602

6-22

1.

Slide in throttle shaft and install throttle plate

using new screws (if furnished in repair kit). Before tightening the screws, the plate must be

centered in the throttle bore.

throttle lever to the completely closed position.

Seat the plate by gently tapping screwdriver and then tighten the screws. Install seal, throttle stop lever, and collar on the throttle shaft end.

FIGURE

6-27.

MIXTURE NEEDLE INSPECTION - LP GAS

To

on

OCCUR

do

so,

it

with a small

HERE

move the

FS-1483

2.

Redistribution or publication of this document by any means, is strictly prohibited.

Install the idle and main adjustment screws and

turn

in

until lightly seated. For preliminary set-

tings, turn the idle screw out

main screw out

2-1/2

1

(&

(f1/4)

turns.

1/4)

turn and the

-1

Forcing the mixture adlustment screws tight will damage the

needle and seaf. Turn in only until tension

3.

Join the upper and lower sections of the carbure-

is

felt.

tor and install bowl plug and washer. When thecarburetor is installed on set, make final

4.

adjustments

to

mixture screws as specified in Carburetor Mixture Screw Adjustments in this section.

Regulator

A two stage regulator (see Figure

LP

deliver vaporized

gas fuel to the carburetor. The

primary stage of the regulator receives

container pressure and reduces itto the low pressure

required for set operation. The secondary stage of

the regulator restricts fuel flow through the regulator

until vacuum from the engine creates a demand for fuel. Fuel flows through the regulator only when the engine is cranking or operating and stops flowing when the engine is stopped.

6-28)

is used to

LP

gas at

SECONDARY

DIAPHRAGM

PRIMARY

VALVE

--*

,@

o

e

9--

SECONDARY

VALVE

-2

e

0

-

FS-1598

FIGURE

6-28.

LP

GAS REGULATOR

The regulator will normally require very little atten-

tion if the set is used on a regular basis and operated on clean high quality fuel. Most regular malfunctions can be traced to the following two sources:

Hardened diaphragms and seats due to extended periods of non-operation.

.

Dirt or foreign matter embedded on valves and

valve seats.

FIGURE

&-

6-29.

REGULATOR ASSEMBLY

DIAPHRAGM

PRIMARY

XFS-1600

A regulator that has been operated and then stored for any length

of

time may require rebuilding or

replacement. Diaphragms and gaskets tend to dry,

as

shrink, and harden

the lighter petroleum ends evaporate. Use the test procedure specified in the Regulator Test section to check regulator operation and then rebuild or replace as required. Repair kits include detailed and illustrated installation instruct-

ions.

A

regulator that has granules of foreign matter embedded on the secondary seat may cause inconsistent starting or idling. These granules are seldom the result

of

insufficient filtration. The foreign matter

6-23

is dissolved in the liquid propane and forms into gra-

Redistribution or publication of this document by any means, is strictly prohibited.

nules as the fuel is vaporized. Remove regulator front

cover and diaphragm assembly (see Figure 6-29) to check for dirt or oil deposits.

If

granules are embedded in the Vitton rubber of the secondary valve, wash the valve and seat clean.

FILTER ELEMENT

Regulafor

Test:

The regulator may be bend tested

using compressed air and a simple automobile fuel

pressure gauge. Use the following procedure to test.

FIGURE 6-30. REGULATOR TEST

1. Attach the pressure gauge to the test port on the back of the regulator as shown in Figure

6-30.

2. Attach a pressure hose to the inlet opening and open the air pressure valve.

3.

If the primary seal is sound, the gauge should

(10.3

read approximately 1-1/2 psi

pressure should remain constant.

kPa) and the

A

fluctuating

pressure reading indicates a bad primary seat.

4. Close the air pressure valve and observe the pressure gauge. The pressure should remain constant. If the pressure reading drops, the secondary

seat

is

leaking.

If the regulator does not pass either test, re bui

It

or replaced.

Fuel

Filter

it

must be

The fuel filter (see Figure6-31) removes solid impuritiessuch as rust orscale from the LP-gas before they

can clog the regulator orcarburetor.

the filter housing traps iron

or

A

magnet within

rust particles while a filter element traps non-magnetic particles. The fuel filter operates at container pressure and must be carefully assembled to prevent leakage. Use the fol-

lowing procedures to disassemble and clean:

GASKETS

FS-1614

FIGURE 6-31. FUEL FILTER

4. If filter element is clogged, wash element in kerosene and blow dry with low pressure

(35

psi/241 kPa) compressed air. Replace filter element if damaged.

5.

Wipe the center stud magnet clean

of

any rust

or

scale particles that have collected.

6.

Install clean filter element using two new gaskets and securely tighten center stud nut.

7. Place a new O-ring in the filter bowl sealing groove.

8.

Align reference mark on filter bowl with reference

mark on filter body and install four capscrewsand

four lock washers. Tighten capscrews to 56 to 74

in-lbs (6.5 to

8.3

Nom) torque. When fuel system

is pressurized, check filter for leaks.

Remove the four capscrews and lock washers

that secure the filter bowl to the filter body. Separate filter bowl from filter body and discard

the O-ring seal.

Remove nut and washer from center stud and pull out the filter element.

6-24

P

Redistribution or publication of this document by any means, is strictly prohibited.

-

FIGURE

Solenoid

The solenoid valve (see Figure tive fuel shutoff whenever the generator set is stopped. The solenoid must be energized before fuel will flow to the regulator. Service is limited to replacing the complete valve assembly if properly. The valve may be bench tested by connecting battery positive tery negative

plunger assembly should withdraw and open the valve when the solenoid is energized. Replace the solenoid valve if it does not operate properly.

Valve

6-32.

SOLENOID

(B+)

to the top terminal and bat-

(B-)

to the grounded terminal. The

VALVE

6-32)

provides a posi-

it

does not operate

ES-1553

6-25

Redistribution or publication of this document by any means, is strictly prohibited.

.

6-26

.

Redistribution or publication of this document by any means, is strictly prohibited.

Section

INTROD

The control svstem includes all functions that relate to starting, monitoring for fault conditions, instrumentation, battery charging, and stopping. This section covers how the control operates, where the components are located, and basic troubleshooting procedures. Separate control systems are used for the NHE and NHEL series generator sets. Each system is covered separately in this section.

7

-

UCTlO

Control

N

NHE CONTROL DESCRIPTION

The generator set control (see Figures consists of the following components:

Printed Circuit Board Assembly Panel Mounted Start/Run/Stop Switch

Start Solenoid

Battery Charge Resistor (R6) Optional Remote Start Control

(Kl)

7-1

(Sl)

and

7-2)

A

general description of each component and how it

functions follows:

Printed Circuit Board Assembly

The printed circuit board assembly (see Figure7-3) is the center

PC

board circuitry controls the start, starter disconnecthun, stop, and battery charging functions. The primary components of the relays, one power rectifier, two diodes, one capacitor,

five resistors, and a five ampere fuse. The viceable component is the fuse which is removable from the front of the control panel. Connections to

PC

the

(Pl)

tor lead wiring harness. The on the back of the control panel.

The

be damaged by reversed battery polarity or by a short

of

the generator set control system. The

PC

board include three

only

board are made through an eight pin connec-

mounted on the board and through the four

PC

board assembly mounts

PC

board assembly is designed

so

that it will not

ser-

FIGURE 7-1.

NHE

7-1

sc-1522

CONTROL

S1-Start/Run/Stop switch

Redistribution or publication of this document by any means, is strictly prohibited.

SZ-Low

oil

S3-Breaker points CR1-Power rectifier CR6Field rectifier F1-Fuse

B1-Starter

G1-Generator

pressure cut-out switch

El-Spark plug EZ-Spark plug E3-Fuel pump R6-Battery charge resistor H1-Choke heater element K1-Start solenoid KZ-Generator relay (AC) K3-Run relay K4-Start relay

FIGURE

7-2.

TYPICAL CONTROL SCHEMATIC - GASOLINE

in the lead wires from the board or remote start control.The relays are sealed and filled with dry nitrogen for maximum contact life.

Start/Run/Stop Switch

The Start/Run/Stop switch

(Sl)

is a single pole, double throw (SPDT) rocker type switch that is used for starting or stopping the generator set. Placing the switch in either the Start

or

Stop position will initiate the appropriate control function. The switch will automatically return to the center (Run) position when released. The switch is mounted on the control

panel and is removable for service department.

Start Solenoid

The

K1

start solenoid is used for opening or closing the circuit between the starter motor and the battery. Because of the high current loads imposed during starting, the start solenoid duty contacts rated to withstand

is

designed with heavy

300

amperes. A sin-

gle small terminal providesaconnection pointforthe

12

volt DC solenoid coil. Two large studs provide connection points for the battery cables. The solenoid is mounted inside the control.

Battery Charge Resistor

The battery charge resistor is a fixed value

50

watts) resistorthat limits the batterycharge rate to

no more than

1

ampere. The charge rate may not be

(2.5

ohm,

altered. The resistor mounts between the left cylinder

(as viewed from flywheel end) and the engine to

generator adapter.

Optional Remote Start Control

The remote start control is an optional accessory that

allows the generator set to be started, monitored, and stopped from a remote location. The deluxe control includes a running time meter and battery condition

meter. Remote control panels are usually mounted

on the vehicle dashboard.

NHE CONTROL OPERATION

This operation description applies to

generator sets. The schematic diagram shown in Figure

7-2

is intended as an example to help follow the circuit description. Always refer to the specific wiring diagram that corresponds to the model and spec

number

of

the generator set when troubleshooting

problems.

NHE

series

-

7-2

CONTROL PANEL

Redistribution or publication of this document by any means, is strictly prohibited.

PC

BOARD

ASSEMBLY

\

REAR VIEW

fi

REMOTE CONNECTOR SOCKET. NOTE TAB IS

AT

BOTTOM

FIGURE

OF

SOCKET

7-3.

NHE CONTROL PANEL ASSEMBLY

STOP

GND STRT

COMPONENT SIDE

SC-1521

Starting

Placing the Start/Run/Stop switch in the Start posi-

tion connects battery ground (B-) to the K4 start

relay. This energizes the K4 relay which closes two

sets of contacts (K4-2,8 and K4-9,15) that connects battery positive (CR4+), T1 ignition coil, E3 fuel pump, and K1 start solenoid. Connecting B+ as described produces the

following control responses:

0

Flashes the field to ensure that there is adequate residual magnetism to induce voltage build-up.

0

Energizes the ignition coil (T1 ignition spark when the breaker points open and close.

Energizes the fuel pump (E3) which begins pump-

ing fuel to the carburetor.

Energizes the K1 start solenoid to close the K1

contacts.

Closing the K1 start solenoid contacts connects

the starter motor. This energizes the starter motor

which begins to crank the engine to initiate starting.

(B+)

to

the generator field windings

)

so

it

can produce an

B+

to

Starter Lock-Out-Run

When the engine starts, the low oil pressure switch

(52) closes to connect battery ground (B-) to the K3 run relay. put voltage from the generator is supplied to the

choke heater element (Hl) and to the K2 generator

relay. This activates the heating element (which

opens the choke) and also energizes the K2 relay. Energizing the K2 relay closes one set of contacts

(K2-23) that connect B+ to the K3 run relay. This energizes the K3 relay which opens two sets of contacts to produce the following control responses:

Closing the K3-9,15 contacts (which parallel the

K4-2,8 contacts) provides an alternate pathway for

supplying Pump.

0

Opening the K3-1,8 contacts disconnects B+ (CR4 positive terminal) from the generator field windings.

o

Closing the K3-2,8 contacts connects B+ to run light, time meter, and battery condition meter.

0

Opening the K3-9,16 contacts disconnects B+from

the K4 start relay causing

As

the engine comes

B+

to the T1 ignition coil and

it

up

to speed, AC out-

to de-energize.

E3

fuel

7-3

De-energizing the K4 relay opens the K4-2,8 and K4-

Redistribution or publication of this document by any means, is strictly prohibited.

9,15 relay contacts. Opening the K4-2,8 contacts has no effect since they are in parallel with the closed

K3-9,15 contacts which connect coil and thefuel pump. Opening the K4-9,15 contacts disconnects energizing the K1 start solenoid disconnects B+from the starter motor which stops cranking.

When the S1 switch is placed in the engine continues to run. Relays K2 (generator relay) and K3 (run relay) areenergized while relays K1 (start solenoid) and K4 (start relay) are de-energized. Generator voltage is rectified to DC by the CR1 power rectifier and supplied charge resistor constant rate operation.

B+

from the K1 start solenoid. De-

to

the battery through the

(R6).

This charges the battery at a

(1

ampere maximum) during set

B+

to the ignition

RUN

position, the

Stopping

Placing the Start/Stop/Run switch (Sl) in the Stop

position grounds the K3 run relay. This de-energizes the K3 relay which opens the K3-2,8 and K3-9,15 relay

contacts to disconnect B+ from the ignition coil, fuel

solenoid, run light, meters, and K5 solenoid. De-

K5

energizing the tacts which holds the K3 relay grounded. This prevents the set from restarting

released from the Stop position. Without ignition or fuel, the engine stops. As the

generator output voltage drops, the K2 generator

relay also de-energizes. All components return to their de-energized position following set shut-down.

CR1 prevents the battery from discharging through the generator windings while the set is stopped.

NHE

CONTROL TROUBLESHOOTING

Use the troubleshooting guide to help locate prob-

lems related to the NHE control. Figures 7-1 and

show the location

Refer to the wiring diagram in Figure

of all terminal connections.

The troubleshooting guide is divided into six sec-

tions. After identifying the problem, refer to the guide for the possible cause and the recommended corrective action.

-

relay closes the K5-30, 87A con-

if

the S1 switch is

of

most of the control components.

7-2

for location

7-3

,

Trouble

Engine Does Not

Crank

TROUBLESHOOTING

Possible Cause

1.

If

engine cranks at set but

not at remote control panel,

fault is due to:

a. open circuit in remote control b. remote start switch faulty

2. If engine cranks at remote control panel but not at set,

fault is due to: a. open circuit in wiring between

S1 switch and PC board, or

b. faulty S1 switch

3. Insufficient voltage for

cranking due to: a. Battery not charged, or

b. Terminal connections loose

or dirty

THE

NHE CONTROL

Corrective

1

a.

Check for continuity and and correct if circuit is open

Replace remote start

lb.

control switch

2a.

Check for continuity and correct if circuit is open

2b.

Replace

3a.

Check condition of battery and recharge or replace

3b.

Clean and tighten all connections at battery,

K1

starter motor

can cause severe personal injury or death. Disconnect

the negative battery at the battery ferminal before servicing.

S1

start solenoid, and

Action

switch

(-)

.

cable

4. Control fuse

F1)

is

open

7-4

4.

Replace fuse

(5

ampere)

TROUBLESHOOTING THE NHE CONTROL

Redistribution or publication of this document by any means, is strictly prohibited.

Trouble

Engine

Does

Not Crank

(cont.)

Engine Cranks But Does Not Start

Possible Cause

5.

Connect a voltmeter bitween terminal S on the start solenoid and ground. Check for battery

voltage when position. fault is due

a.

K1

b.

defective K1 relay, or

S1

is placed in Start

If

voltage is present,

to:

relay not grounded,

c. defective starter

6.

If

voltage is not present as described

5

in step

test, fault is due to:

a. open circuit between K1 relay

and control PC board, or

b. defective control PC board.

1. Faulty ignition due to worn

or

fouled spark plugs, worn ignition points, incorrect ignition timing, or faulty plug wires.

2. Faulty fuel system due to sticking choke, faulty fuel pump, or carburetor mixture screws incorrectly adjusted.

Corrective Action

5a.

Tighten solenoid bracket mounting screw

K1

5b. Replace

start solenoid.

5c. Refer to Electric Starter section for

test and service procedures.

6a.

Check for continuity and correct if circuit is open.

6b. Replace control PC board.

1. Refer to Ignition System section section for test and service procedures.

2.

Refer to Fuel System section for test and service procedures.

Engine Starts But Stops When Start Switch is Released

3. Connect a voltmeter between positive (+)terminal on coil and ground. Check for battery voltage when S1 is placed in the

Start

position.

If the voltage is not present,

fault is due to:

a.

open circuit between coil and control

b. defective control PC board.

~~ ~

1.

Low dlpressure switch not closing

due to:

a. low oil level b. open circuit between switch and

control c. defective low oil pressure switch d. low oil pressure.

2.

Output voltage from generator not being supplied to control due to:

a. defective charge resistor b. open circuit in wiring between

generator and control.

c. defective bridge rectifier

d. no output voltage from generator.

3a. Check for continuity and correct

if

correct

circuit is open.

3b. Replace control PC board.

laycheck oil level and add oil if low.

1 b. Check for continuity and correct if

circuit is open. 1 c. Replace low oil pressure switch. Id. Refer to Lubrication system section

for test and service procedures.

2a. Test

R6

charge resistor

and replace

if

defective.

(2.5

ohm)

2b. Check for continuity and correct

if circuit is open.

to

2c. Refer

Generator section

for test and service procedures. 2d. Refer

to

Generator section

for test and service procedures.

7-5

TROUBLESHOOTING THE NHE CONTROL

Redistribution or publication of this document by any means, is strictly prohibited.

Trouble

Engine Starts But Stops When Start Switch is Released (cont.)

Engine Starts And Runs; Then Stops. Set Restarts Immediately Set Restarts After Cooling Down

or

Possible Cause

3.

Defective control PC board.

1.

Fuel level is below generator set fuel pickup tube or oil level is low.

2.

Faulty choke operation due

to

sticking choke linkage,

incorrect choke adjustment,

open circit in wiring

between choke heater and

generator, or defective choke

heater.

3. Vapor lock due to: a. high ambient air temperature b. faulty fuel pump.

4.

Breaker points sticking.

Corrective Action

3.

Replace control PC board.

1.

Check fuel and oil levels

and refill as necessary.

2.

Refer

to

Fuel System section for testing and service procedures.

3a. Remove any objects or debris

that may restrict airflow to and from the set

3b. Refer to Fuel System section

for test and service procedures

4.

Replace breaker points.

.

Low Battery

5.

Contaminated fuel.

1. Weak or discharged battery. generator set charger will not recharge a battery that

is in a very

2.

Load connected while set is turned

3. Disconnect the negative battery cable at the battery and remove control lead P1-6 from the battery positive terminal on the solenoid. Connect a and between the P1-6 lead wire and the stud terminal on the

running, the ammeter should read between

If

meter shows battery is discharging,

fault is due to:

a. defective generator charge

winding

b.

CRI power rectifier open.

low

state

of

charge.

to

battery

off.

K1

start

DC

5

ampere fuse in series

K1

solenoid. With set

0

and 1 ampere.

(-)

(+)

ammeter

5.

Refill tank with fresh fuel.

1. Connect a separate battery charger to bring battery up to full charge.

2.

Turn

off

load.

3a. Refer to Generator section

for testing and service

procedures.

3b. Replace control

PC

board.

7-6

TROUBLESHOOTING THE NHE CONTROL

Redistribution or publication of this document by any means, is strictly prohibited.

Trouble

Run Lamp, Time Meter,

or

Battery Condition Meter Does Not Operate

Possible Cause

Open circuit between

6

or

terminal

plug and terminal

remote connector

6

on

Start/Run/Stop switch. Open circuit between ground

terminals on lamp and terminal

or

1

on remote

meters

Start/Run/Stop switch.

If

battery condition meter works but time meter does not operate, time meter is defective.

If

time meter works but battery condition meter does not operate, verify that jumper wire is connected between terminals 5

and

6

on

remote start/stop switch.

If

jumper is in place, connect

a

voltmeter between the positive

on

terminal

battery charge meter

and ground. Use the following

to determine fault:

a. If reading equals battery

voltage minus

battery meter

If

reading does not equal

b.

battery voltage minus

10

volts,

is

defective.

10

volts,

zener diode is defective.

Corrective Action

1.

Check for continuity and

correct if circuit is open

Check for continuity and

2.

correct if circuit is open

Replace time meter

3.

Replace battery condition

4a.

meter Replace zener diode

4b.

-

7-7

NHEL CONTROL DESCRIPTION

Redistribution or publication of this document by any means, is strictly prohibited.

The NHEL generator set control (see Figures7-4and 7-5) consists of the following components:

Printed Circuit Board Assembly Panel Mounted Start/Run/Stop Switch Start Solenoid (Kl) Battery Charger Resistor (R6) Optional Remote Start Control

(Sl)

Stop switch, start solenoid, battery charge resistor, and remote start control. The following sections pro-

vide a description

of

the stop relay and blocking

diode.

Stop

Relay

(K5)

The K5 stop relay is used to latch off the generatorset

(Sl)

when the Start/Run/Stop switch

is placed in the Stop position. This prevents the set from restarting when the switch is momentarily placed in the Stop

position and then released. The K5 relay mounts on

the air cleaner adapter.

Stop Relay (K5)

Blocking Diode (CR5)

The first five components listed for the

NHEL

control are either the same or similar to the components in the NHEcontrol. Referto and Figure7-6forageneral description

NHE

Control in thissection

of

the printed

circuit board assembly, panel mounted Start/Run/

TO IGNITION

COIL

B+

(From

K5-85)

Blocking Diode

(CR5)

The CR5 blocking diode is used to protect the control

circuitry from reverse-flow transient currents. When the set is shut down, various magnetic fields within the generator collapse. This causes transient cur-

rents that can damage the control

if

not blocked. The CR5 diode is spliced into the control wiring harness between the circuit board assembly and Start/Run/ Stop switch.

FIGURE

7-4.

NHEL

7-8

SC-1520

CONTROL

Sl-Start/Run/Stop switch

Redistribution or publication of this document by any means, is strictly prohibited.

S2-Low oil pressure cut-out switch S3-Breaker points CR1-Power rectifier CRCField rectifier F1-Fuse B1-Starter motor G1-Generator

El-Spark plug E2-Spark plug E3-Fuel solenoid RG-Battery charge K1-Start solenoid KBGenerator relay K3-Run relay K4-Start relay K5-Stop relay

resistor

(AC)

FIGURE

7-5

TYPICAL CONTROL SCHEMATIC - LP GAS

NHEL CONTROL OPERATION

This operation description applies to generator sets. The schematic diagram shown in Fig-

ure

7-5

is intended as an example to help follow the circuit description. Always referto thespecific wiring diagram that corresponds to the model and spec

number

of

the generator set when troubleshooting

problems.

NHEL

series

Starting

Placing the Start/Run/Stop switch in the Start posi-

(B-)

tion connects battery ground relay. This energizes the K4 relay which closes two sets of contacts (K4 2,8 and K4-9, 15) that connect battery positive

(CR4+),

T1 Ignition coil, E3 fuel solenoid valve, K5

(B+)

to the generator field windings

stop relay, and K1 start solenoid. Connecting described produces the following control responses:

Flashes the field to ensure that there is adequate residual magnetism to induce voltage build up.

Energizes the ignition coil producing an ignition spark when the breaker points open and close.

to the K4 start

(Tl)

so

it can begin

B+

as

Energizes the fuel solenoid valve (E3) which

opens to allow fuel to flow to the carburetor.

Energizes the K5 stop relay to open the K5

contacts.

0

Energizes the K1 start solenoid to close the K1 contacts.

Opening the K5 stop relay contacts opens the circuit

that holds the K3 run relay grounded. This allows the

K3 relay to energize when connected to Closing the K1 start solenoid contacts connects

B+.

B+

to the starter motor. This energizes the starter motor which begins to crank the engine to initiate starting.

Starter

Lock-Out - Run

When the engine starts, the low oil pressure switch

(S2)

closes to connect battery ground

run relay. As the engine comes up to speed,

(B-)

to the K3

AC

out-

put voltage from the generator is supplied to the K2

generator relay. This energizes the K2 relay which closes one set

of

contacts (K2-2,5) that connects

B+

to the K3 run relay. This energizes the K3 relay which opens two sets of contacts and closes two sets of

7-9

CR5 DIODE

Redistribution or publication of this document by any means, is strictly prohibited.

t

0

STOP

COMPONENT

GND

SIDE

STRT

SC-1523

FIGURE

contacts to produce the following control responses:

0

Closing the K3-9,15 contacts (which parallel the K4-2,8 contacts) provides an alternate path way for supplying

noid valve.

Opening the K3-1,8 contacts disconnects (CR4 positive terminal) from the generator field windings.

Closing the K3-2,8 connects time meter, and battery condition meter.

Opening the K3-9,16 contacts disconnects from the K4 start relay causing energize.

De-energizing the K4 relay opens the K4-2,8 and K49,15 relay contacts. Opening no effect since they are in parallel with the closed K3-9,15 contacts which connect

coil and the fuel solenoid. Opening the K4-9,15 con-

tacts disconnects

energizing the K1 start solenoid disconnects

the starter motor which stops cranking.

B+

to the

T1

ignition coil and fuel sole-

B+

the

K4-2,8 contacts has

B+

from the K1 start solenoid. De-

7-6

NHEL CONTROL PANEL ASSEMBLY

B+

to the run light,

B+

it

to de-

to the ignition

B+

from

When theSl switch is placed in theRUN position, the engine continues to run. Relays K2 (generator relay),

K3 (run relay), and

while relays K1 (start solenoid) and K4 (start relay)

are de-energized. Generator voltage by the CR1 power rectifier and supplied to the battery

through the charge resistor (R6). This charges the

battery at a constant rate ing set operation.

K5

(stop relay) are energized

is

rectified to

(1

ampere maximum) dur-

DC

Stopping

Placing the Start/Stop/Run switch

position grounds the K3 run relay. This de-energizes the K3 relay which opens the K3-2,8 and K3-9,15 relay contacts to disconnect

solenoid, run light, meters, and

energizing the K5 relay closes the

tacts which holds the K3 rela9 grounded. This pre-

vents the set from restartin-g if the

released from the Stop position.

Without ignition or fuel, the engine stops. As the

generator output voltage drops, the K2 generator relay also de-energizes. All components return to

their de-energized position following set shut-down.

CRl prevents the battery from discharging through the generator windings while the set is stopped.

B+

from

(Sl)

in the Stop

the

ignition coil, fuel

K5

solenoid.

K5-30,

87A con-

S1

switch is

De-

b

7-1

0

NHEL

Redistribution or publication of this document by any means, is strictly prohibited.

Use the troubleshooting guide to help locate problems related to the

show

Refer to the wiring diagram in Figure 7-5 for location of all terminal connections.

CONTROL TROUBLESHOOTING

NHEL

control. Figures7-4 and7-6

the

location

of

most

of

the

control components.

TROUBLESHOOTING THE NHEL CONTROL

six

The troubleshooting guide is divided into tions. After identifying the problem, referto theguide

for

the

possible

tive action.

cause

and

the

recommended

sec-

correc-

Trouble

Engine

Does

Not

Crank

Possible

1.

If

engine cranks at set but

not at remote control panel,

fault is due to:

a. open circuit in remote control

wiring

b. remote start switch faulty

2. If engine cranks at remote control panel but not at set, fault is due

a. open circuit in wiring between

S1 switch and PC board

b. faultyS1 switch

3. Insufficient voltage for

cranking due to:

a. battery not charged

b. terminal connections loose

or dirty

to:

Cause

Corrective Action

Check for continuity and

1

a.

and correct if circuit open Replace remote start

lb.

control switch

Check for continuity and

2a.

if

correct Replace S1 switch

2b.

Check condition of battery

3a.

and recharge or replace

Clean and tighten all

3b.

connections at battery,

K1 start solenoid, and

starter motor

circuit is open

aWARN"G

can cause severe personal injury or death. Disconnect

the

negative battery

at the battery terminal before

servicing.

.

'

Short circuiting

!

thebafferycables

is

(-1

cable

.

*

4. Control fuse (Fl) is open

5.

Connect a voltmeter between terminal noid and ground. Check for battery voltage when placed in Start position. If voltage due

a.

b.

c. defective starter

6.

If voltage is not present as described in step

fault is due to:

a. open circuit between

b.

S

on the start Sole-

S1

is

present, fault

to:

Kl

relay not grounded,

defective

and control PC board defective control PC board

K1

relay

5

is

test,

7-1

is

K1

relay

1

Replace fuse

4. Tighten solenoid bracket

5a.

mounting screws Replace

5b.

Refer to Electric Starter

5c.

section for test and service procedures

Check for continuity and

6a.

correct if circuit is open Replace control

6b)

(5

K1

start solenoid

ampere)

PC

board

TROUBLESHOOTING THE NHEL CONTROL

Redistribution or publication of this document by any means, is strictly prohibited.

Trouble

Engine

Cranks But

Does Not Start

Engine Starts But Stops When Start Switch

Is

Released

Possible

1.

Faulty ignition due to worn or fouled spark plugs, worn ignition points, incorrect ignition timing, or faulty plug wires.

2.

Faulty fuel system due to carburetor mixture screws incorrectly adjusted, plugged fuel filter, faulty regulator, or faulty fuel solenoid.

3.

Connect a voltmeter between positive coil and ground. Check for battery voltage when placed in the Start position. If voltage is not present, fault is due to: a. open circuit between coil and

b. defective control

1.

Low oil pressure switch not closing a. low oil pressure

b.

c. defective low oil pressure

d.

(+)

terminal on

control or

due

to:

open circuit between switch and control,

switch,

low oil pressure.

Cause

SI

PC

board.

is

Corrective Action

1.

Refer to Ignition System section for test and service procedures

2.

3a.

3b.

1 1

1

Refer to Fuel System section for test and service procedures

Check for continuity and correct if circuit is open.

Replace control PC board.

a.

Check oil level and add

oil

if

low

b.

Check for continuity and

if

correct

c.

Replace low oil pressure

switch

Refer to Lubrication system

d.

section for test and service procedures

circuit is open

2.

K5

relay contacts not opening due to: a.

K5

relay circuit open or

b. defective

3. Output voltage from generator not being suppled

to control due to: a. defective charge resistor.

b.

open circuit in wiring between generator and control,

c. defective bridge rectifier, or

d.

no output voltage from generator

4.

Defective control PC board

K5

relay.

Check for continuity and

2a.

correct if circuit is open

2b.

Replace

3a.

Test R6 charge resistor

(2.5

defective.

Check for continuity and

3b.

correct

Refer to Generator section

3c,d.

for test and service

procedures. Replace control PC board

4.

K5

ohm)

and replace if

if

circuit is open

relay

7-1

2

TROUBLESHOOTING THE NHEL

Redistribution or publication of this document by any means, is strictly prohibited.

CONTROL

Trouble

Engine Starts And Runs; Then Stops. Set

Restarts Immediately Set Restarts After Waiting Several Minutes

Low Battery

or

Possible Cause

1.

Oil

level is low

2.

Ditty

fuel restricting fuel filter causing filter to freeze up.

3. Breaker points sticking

4.

Contaminated fuel.

1.

Weak

or

discharged battery Generator set charger will not recharge a battery that

is

in a very low state

2.

Load connected to battery while set is turned

3. Disconnect the negative battery cable at the battery

and remove control lead from the battery positive terminal on the K1 start solenoid. Connect a ammeter and 5 ampere fuse in series between the P1-6 lead wire and the stud terminal on the

K1

solenoid. With set running, the ammeter should read between If meter shows battery is

discharging, fault is due to: a. defective generator charge

winding or

b.

CRl power rectifier open.

or

charge.

off.

DC

0

and 1 ampere.

(-)

P1-6

(+)

Corrective

1.

Check fuel and oil levels

and refill as necessary

2.

Clean fuel filter. Refer to Fuel System section for service procedures

3 Replace breaker points

4.

Refill tank with fresh fuel

1.

Connect a separate battery charger to bring battery

full

up to

2.

3a.

3b.

off

Turn

Refer to Generator section

for testing and service

procedures. Replace control PC board

load.

Action

charge.

7-1

3

TROUBLESHOOTING THE

Redistribution or publication of this document by any means, is strictly prohibited.

NHEL

CONTROL

Trouble

Run Lamp, Time Meter, or Battery Condition Meter Does

Not

Operate

Possible Cause

-

Open circuit between

1.

6

or

terminal plug and terminal Start/Run/Stop switch

Open circuit between ground

2.

terminals on lamp or meters and terminal Start/Run/Stop switch

If battery condition meter

3.

works but time meter does not operate, time meter is defective.

If time meter works but

4. battery condition meter does not operate, verify that jumper

wire is connected between terminals start/stop switch. If jumper is in place, connect a voltmeter between the positive terminal on battery charge meter and ground. Use the following to determine fault:

a.

If

reading equals battery voltage minus battery meter is defective.

b. If reading does not equal

battery voltage minus

zener diode

remote connector

6

on

1

on remote

5

and 6 on remote

10

volts,

is

defective.

10

volts,

Corrective Action

1)

Check for continuity and correct if circuit is open

2)

Check for continuity and

is

correct if circuit

3)

Replace time meter

4a. Replace battery condition

meter

4b. Replace zener diode

open

-

7-1

4

Section

Redistribution or publication of this document by any means, is strictly prohibited.

8

=

Generator

.

INTRODUCTION

The NHE and NHEL generator sets have a 4-pole, revolving field generator with transformer voltage regulation. All AC load connections are made

through long generator lead wires that connect

directly to a customer supplied junction breaker provides overcurrent protection for the generator and also functions as an on/off switch in

the load circuit.

box.

A

circuit

GENERATOR DESCRIPTION

The generator (see Figure 8-1) consists of thefollowing major components:

Stator and Housing Rotor Voltage Regulating Transformer Field Current Rectifier Brushes

Wiring Harness

Stator and Housing

During generator set operation, AC current is produced in the windings of the stator. All stators have two AC output windings (T1-T2 and T3-T4) for powering the load and a separate winding (81-82) for battery charging. All stators also have two lead wires (Si and S2) that are used with the voltage regulating

transformer.

The stator mounts inside the generator housing and

is held in position with four clamps and four capscrews. A series of air-intake openings in the end of

the housing allow

housing for generator cooling. The housing also provides a mounting point for the starter, rear bearing, brushes, control, fuel pump, and voltage regulating

transformer. The complete stator and housing

assembly bolts to the engine-to-generator adapter.

Rotor

The 4-pole rotor provides the rotating magnetic field that is required for generating an AC voltage potential in the stator windings. The DC current required

for field excitation is supplied through two slip rings that mount on the rotor shaft.

The inner end of the rotor is connected directly to the engine crankshaft using a tapered seat shaft coupling and through-bolt. The slip ring end of the rotor is supported bya single bearing. The bearing fits inside the generator housing bearing.

Cooling airflow for the generator is provided by a centifugal fan that mounts on the inner end of the rotor shaft. The fan also serves as a mount for the stator ring gear.

cool

air to be drawn inside the

Voltage Regulating Transformer

The voltage regulating transformer (see Figure

helps

to

provide stable generator output voltage

under varying load conditions. Voltage transformers are constructed with two primary windings and a single secondary winding. Each primary winding

(Hl-H2 and H3-H4) is connected in series with one of the generator AC output windings. The transformer secondary winding is connected in series with the

field current circuit. Taps on the secondary allow for field current adjustments.

The voltage regulating transformer mounts on the

outside of thegenerator housing and is enclosed with a special cover. The cover must be in place during operation for transformer cooling.

Field Current Rectifier

TheCR4 rectifier isafull wave bridge rectifierthat is used to rectify a portion of the generator AC output voltage to

DC

for field excitation. The positive and negative terminals of the rectifier are connected to the generator brushes. The rectifier mounts inside the generator set control and may be accessed by removing the control panel.

(CR4)

8-2)

Brushes

The brush block assembly consists of a single brush block with the generator housing and can the small plate at the rear of the housing.

Wiring Harness

A

separate wiring harness is provided for connecting the generator set to the RV electrical system. All lead wires are stranded copper wire to withstand vibration. The lead wires must be protected with flexible conduit which must be provided by the RV manufacturer. A 3/4 inch conduit elbow is provided to facilitate installation. The load wire conductors are black, the neutral conductors are white, and the ground conductor is green. The exit point for the wiring harness is nearthevoltage regulating transformer.

two

brushes. The brush block mounts inside

be

accessed by removing

GENERATOR OPERATION

Generator operation involves the control, stator, rotor,

voltage regulating transformer, brushes, and full wave

bridge rectifier. The schematic shown in Figure 8-3 is intended as an example to help follow the generator

operating description. Always refer to the specific sche-

matic that correspondsto the model and spec number

the generator set when troubleshooting problems. When the Start/Run/Stop button is placed in the Start

position, the rotating field (rotor) is connected to battery

of

,

Redistribution or publication of this document by any means, is strictly prohibited.

FIGURE

8-1.

GENERATOR

8-2

G-1171

positive

Redistribution or publication of this document by any means, is strictly prohibited.

(B+)

to ensure adequate residual magnetism to

voltage build-up. As the engine starts and speed

increases, the rotating field induces avoltage build-up in

the

stator windings. A portion of

ated in the stator windings bridge rectifier. The

DC

current is supplied to the rotating

is

rectified

the

AC

current gener-

to

DC

by

the

CR4

field windings to create the strong magnetic field required for generating the rated current.The ACvoltage build-up stabilizes at approximately

128

volts when the

engine reaches governed speed.

To

prevent an excessive voltage drop when a load is applied to the generator, a method for regulating the AC output voltage is required. The voltage regulating trans-

former allows the generator to provide a stable AC out-

put voltage under varying load conditions. Each trans-

former primary winding

(Hl-H2

and

H3-H4)

is connected in series with one of the stator AC output windings. The full AC output current produced by the generator flows through these two primary windings. Increasing or decreasing the current output from the transformer winding produces a corresponding increase or decrease in the primary current produced in the secondary winding. The secondary winding is connected in series with the circuit that supplies AC current for rectification to DC field current.

transformer secondary winding. This

boosts

the

DC

field current to a higher level to offset the voltage

drop that would normally occur when a load is applied. reduces the

In

the

same

manner, decreasing the

DC

field current to offset the voltage rise

load

that would normally occur when a load is removed. Continuously adjusting the field current as the load changes is how voltage regulaton is achieved.

GENERATOR TROUBLESHOOTING

Use the following troubleshooting guide to help locate problems related to the generator. Figures show the location of most of the generator components. Refer to the wiring diagram in Figure of all terminal connections. The troubleshooting guide

divided into four sections. After identifying the problem,

refer to the guide for the possible cause and the recommended corrective action.

8-1

and

8-4

for the location

8-2

is

During operation, adding load increases the current flow through the transformer primary windings which causes a corresponding increase in the current output from the

STATOR

HOUSING

LOAD(8LACKl.

NEUlRlLl

WHITE1.m

GNOIGREENI. TO

10

CB

lRAHSFM1YER GND

TRANSFORMER GND

FIGURE

8-2.

VOLTAGE REGULATING TRANSFORMER

8-3

ES-1557

I-

Redistribution or publication of this document by any means, is strictly prohibited.

I

.I

I

1

I

IB

I

-----

IMP0

R

TA

N

@%@%I

Due

to

sibility of unit lead end identification being

out-ofdate

wire diagrarn/schematic

do

not

supplement,

rely

lead markings by transformer

when troubleshooting. Instead,

check

point

each

lead

to

confirm that unit

from

TT TI

s3

52

s1

R6

K5 K1 H1 G1

F1

T!

the

pos-

with

the

of

this

solely

on

point-fo-

is

wired

TRANSFORMER IGN COIL

IGN

POINTS SWITCH SWITCH -START STOP

RESISTOR RELAY

-

START SOLENOID CHOKE

-

GENERATOR FUSE

1--

1CB2 LOAD

--4-ELACK

-

LOW

011

I’RESSIIRE

-

BATTERY CHARGE

USED WITH

USED WITH GASOLINE ONLY

LPG

ONLY

NOMNALNOLOADVAC

127.5%.5VAC

TODOCREASE

NOMINAL

LOA0

NORMAL4

TO

NOMINALNO

LOAD VAC

E3

E12 CB1.3 CR4 CRS

f.1

BT

u:

A3 A2 A1

FUEL PUMP/OR FUEL SOLENOID SPARK CIRCUIT BREAKERS (AC OUTPUT) BRIDGE RECTIFIER RECTIFIER -USED WITH LPG ONLY CAPACITOR

1

BATTERY STARTER STANDARD REMOTE CONTROL

DELUXE REMOTE CONTROL CONTROL ASSY

r““

NO

VAC

INCREASE

L

PLUG

12V

f

LEADS

6

I

I - I I

74

FIGURE

8-3.

TYPICAL SCHEMATIC

8-4

DELUXE

Redistribution or publication of this document by any means, is strictly prohibited.

REMOTE PANELS

STANDARD

I

REMOTE

I

I I I

I

1

I

I I I I

I

I I

-1

A3

IMPORTANT!

Due to thepos-

sibility

of

unit lead end identification being out-ofdate wire diagnm/schematic of supplemnb do nof dy solely on

lead

markings by transformer

when troubleshoofing. Instead,

check

each lead

point to confinn that

from

unit

pint-io-

is

PrOperY.

with

wired

the

this

p

E3

61

I-

NOTES:

1

JUMPER IS NEEDED FOR BATTERY CONDITION METER

T2

TRANSFORMER

Tl

IGN COIL E3 FUEL PUMP/OR FUEL SOLENOID

s3

IGN POINTS El

s2

SWITCH -LOW OIL PRESSURE

s1

R6

K5

K1 H1 G1 F1

-

SWITCH RESISTOR -BATTERY CHARGE C1 CAPACITOR RELAY

START SOLENOID CHOKE - USED WITH GASOLINE ONLY A3 STANDARD REMOTE CONTROL GENERATOR FUSE

START/STOP CR4 BRIDGE RECTIFIER

-

USED WITH LPG ONLY BT1 BATTERY 12V

FIGURE

8-4.

TYPICAL

2

SPARK PLUG

CB1.2 CIRCUIT BREAKERS (AC OUTPUT)

BT STARTER A2 DELUXE REMOTE CONTROL

A1 CONTROL ASSY

WIRING

DIAGRAM

8-5

I

174

-

TROUBLESHOOTING THE GENERATOR

Redistribution or publication of this document by any means, is strictly prohibited.

Trouble

AC

No

Output

Voltage

Note: This condition may cause the generator set to

stop when the

Start switch is released.

AC Output Voltage Too Low

Too

Or

High

Possible Cause

1.

Open circuit breaker

2.

Open circuit between brush

block and CR4 rectifier.

3.

Brushes stuck in holder or not making good contact with

slip rings

4.

Defective CR4 bridge rectifier

5.

Open, grounded, or

short

circuit in rotor, stator, or

transformer

1.

Engine governor incorrectly adjusted

*2.

Open diode in CR4 bridge

-'

rectifier

Corrective Action

Locate cause of overload

1

)

and correct as required. Reset breaker

2)

Check for continuity and correct if circuit is open

3) Release brushes if jammed in holder. Clean slip rings if dirty.

4) Test rectifier and replace if defective

5)

Test each component for

open, grounded, or shorted windings and replace if defective.

Refer to Governor section

Test CR4 rectifier and

replace if defective

Noisy Generator

*3.

Brushes worn or not making good contact with slip rings

4.

If

generator frequency is

within specified limits but

voltage is incorrect,

transformer is incorrectly connected or defective.

"5.

Open, grounded, or

short

circuit in rotor, stator, or transformer

*causes low AC output voltage

1.

Loose

brush holder

2.

Worn generator end bearing

3.

Rotor and stator rubbing

together due to: a) varnish

lumps, orb) rotor misaligned with crankshaft

Check length of brushes and replace if worn excessively. Clean or replace slip rings.

Adjust tap connections on

transformer secondary windings to obtain correct

voltage. Replace

transformer if voltage cannot

be corrected with adjustments.

Test each component for

open, grounded,

or

shorted

windings and replace if

defective.

1)

Tighten brush holder

2)

Replace end bearing

3a) Check for varnish lumps

between rotor and stator and remove

as

required

3b) Follow specified assembly

procedures to correct rotor

to crankshaft alignment.

.

-.

8-6

TROUBLESHOOTING THE GENERATOR

Redistribution or publication of this document by any means, is strictly prohibited.

Trouble

~~

Generator Overheats

Possible

1.

Generator overloaded due to

Cause

defective circuit breaker

2.

Airflow restricted due

dirt

or debris covering vent

openings in stator housing

3.

Stator windings covered with oil

or

dirt

4.

Open, grounded, or circuit in rotor, stator, transformer

to

short

or

Corrective Action

Remove part

1)

replace circuit breaker. Clear away all dirt

2)

debris as required

3)

Clean stator windings

4)

Test each component open, grounded, windings and replace if defective.

of

load

or

and

for

shorted

GENERATOR

Redistribution or publication of this document by any means, is strictly prohibited.

SERVICE

This section covers generator disassembly and assem-

bly procedures. Referto Figures8-1 and8-2 tolocateand identify the various generator components described in each su b-section.

BRUSH

BLOCK

Generator

Disassembly

Use the following procedures to disassemble the generator:

1. Drain the engine oil while the generator set is still mounted in the vehicle.

2. Remove the generator set from the vehicle and place

it

on

a sturdy work bench. Refer to Set Removal in

Section

5

for the recommended set removal

procedures.

3.

Remove the flywheel guard (from scroll opening) and the noise shield.

4.

The carburetor and intake manifold must be

removed to provide clearance for lifting the generator stator assembly. Disconect the choke heater lead wires, throttle linkage, fuel line, crankcase breather

hose, and preheater tube. Remove the intake manifold as an assembly. Refer to Fuel System in Section 6 for detailed removal procedures.

5.

Disconnect the lead wires from the charge resistor

(quick-disconnect type connections), the low oil

B+

pressure cutoff switch, and the

terminal on the

ignition coil.

6.

Remove the brush block cover and disconnect the

Bt

(outboard) and

B-

(inboard) lead wires from the

brush block terminals.

7.

Pull each brush outward from the holder and at the same time insert a piece of stiff wire into the small hole in the end

of

the stator housing (see Figure 8-5). Carefully guide the wire through the brush block and then release each brush. Verify

thateach brush is held

off

theslip rings by thewire.

HOLE

G-1178

FIGURE

8-5.

BRUSH

BLOCK

-

the drip pan.

13.

Remove the four capscrews, lock washers, and nuts that secure the stator housing to the engine-togenerator adapter.

14. Install a puller on the end of the stator housing as

slip

rings.

Make

removing

8.

Remove the transformer coverand

sfafor

fueled, disconnect the fuel line at the vaporizer

coupling.

9.

Attach the special lifting plate (see Figure 8-6) end of the stator housing using four 5/16-18 capscrews.

Place a pad in front

10. protect the scroll. Attach a hoist or other suitable

lifting device

to

the lifting plate. in Figure84 until it is completelyvertical and resting on the scroll. Remove lifting plate when complete.

Remove the capscrew and

11. secure the ground strap to the drip pan.

Remove the three vibration isolator center screws

12. from the underside of thedrip pan and liftawayfrom

The brushes will

be

damageddur-

incrdisassemblvif notheld offfhe

c&dn wire

is

in place before

assembly.

if

theset is

of

the engine to cushion and

Lift

the set as shown

two

EIT

lock washers that

LP

to

gas

the

x

1

8-8

CAPSCREW,

Redistribution or publication of this document by any means, is strictly prohibited.

FLYWHEEL

PULLER

20.

Use the following procedure to remove transformer from housing:

A.

Remove the braided insulating material from the

transformer primary lead wire (T2-H2 and

H4)

connections.

6.

Cut off the crimped barrel connectors and separate the transformer primary leads from the stator leads.

C. Disconnect the lead wires from the transformer

secondary taps.

D.

Remove the four screws that secure the trans-

former to the stator housing and lift

off

former assembly.

The transformer airgap can be

@@!@I

is

removed from the itansformer.

alferedif fhe mounfing bracket

Do

or remove any screws that pass fhrough the

transformer larninafions.

21.

Use the following procedure to remove the stator from the stator housing.

A.

Remove stator lead wires from the transformer primary leads and secondary taps as described in steps

20A

through

20C.

T4-

the trans-

not

loosen

.

FIGURE

shown in Figure 8-7.

8-7.

STATOR ASSEMBLY

Use

two

5/16-18

REMOVAL

x

1

capscrews to secure the puller to the housing. Tighten puller center screw against rotor through-bolt until housing lifts free

of

rotor and end bearing. Remove puller

when complete.

15.

Carefully

lift

the stator assembly straight up

clears the rotor.

Careless handling

of

the stator

can damage the insulation

Do

not

staior windings, against fhe

16.

Place a 3/8 inch allen wrench in the head of the rotor

mfor

as it

brush the stafor windings

is

lifted clear.

through-bolt. Using a rubber mallet, sharply strike the allen wrench

so

the through-bolt is driven in a counterclockwise (viewed from generator end) direction. Several sharp taps should break loose the through-bolt.

17. Remove the rotorthrough-bolt and in

its

place install the tool shown in Figure 8-8. Use a screwdriver to turn the rotor tool

bottoms. Install a

in

a clockwise direction until it

9/16-12

x

2

capscrew in the end of

the rotor shaft and tighten until rotor breaks loose

from crankshaft. Remove capscrew from end of rotor

when complete.

18. Carefully lift the rotor assembly engine crankshaft and remove rotor

19.

Remove the brush block mounting screws and carefully

lift

out the brush block assembly.

off

the end of the

tool.

until

on

it

the

FIGURE

8-8.

ROTOR

0-1175

TOOL

B.

Redistribution or publication of this document by any means, is strictly prohibited.

Cut

off

the wire ties that secure the stator lead

wires to the inside of the housing.

Cut

only

wire

ties,

not

the tie

supports.

Remove the four stator clamps and capscrews.

C.

D.

Carefully lift the stator straight up until it clears the stator housing.

D.

If transformer was not removed during diassembly, follow step 2c through 2e to connect stator output leads to transformer.

2.

If

the transformer was removed from the stator housing during disassembly, use the following procedures to install the transformer on the stator housing.

-1

on

the stator windings.

windings against the housing as it

clear.

Use the following procedures to assemble the generator:

1.

If

the stator was removed from the housing during disassembly, use the following procedures to install the stator in the housing:

A.

Position the stator

oriented as shown in Figure 8-1; then carefully

lower the stator into the stator housing.

the stator windings. windings against the housing

into position.

B.

Install the four clamps and capscrews that secure the stator to the housing. Tighten capscrews to specified torque.

C.

Route stator lead wires through holes in stator housing as specified in Figure 8-1. Fasten wiring harness to inside of housing using wire ties.

Careless handling tor can damage the insulation

Do

so

the output leads are

Careless handling

for can result

Do

not brush fhe stator

of

the sta-

not brush the

is

of

the

in

damage

as

if is lowered

liffed

sfa-

to

A.

Hold transformer in position for mounting on the stator housing. Install the two mounting screws and tighten securely.

B.

Connect the CR4-AC lead wire to the tranformer

X2

tap and the

tap. Note: This is a preliminary connection that

may require adjustment to obtain the correct generator output voltage. See Transformer Voltage Adjustment section.

C. Strip

D.

off

ends of transformer primary leads

and from stator leads Twist each stator lead around the end of the

corresponding transformer primary lead

H2

and T4 to H4). Place a

connector over the lead ends and crimp tightly

using a

lZGB@l

during set operation. Use only the specified connector and crimping tool when connecting stator leads to transformer primary tools.

E.

Slide a 2-1 insulation over each connection as shown in Figure

8-9.

Si

lead wire to the transformer

1

/2

inch (1 3 mm) of insulation from the

H2

T2

and

T4.

#6

uninsulated barrel

#6

staking tool.

Wire nuts or other non-crimp

type connectors can loosen

/2

inch

(64

mm) long piece of braided

Use a wire tie

to

hold

and H4

(T2

X5

to

'\.

FIGURE

8-9.

BRAIDED

8-1

f

INSULATION

0

w

BARREL

INSULATION

CONNECTOR

ES-1552

insulation securely

Redistribution or publication of this document by any means, is strictly prohibited.

3.

Pull each brush outward from the brush holder and at the same time insert a stiff piece through the small holes in the base of the holder.

The wire holds the brushes off the slip rings dur-

ing assembly. Install brush block in housing and

tighten mounting screws.

4.

Place the rotor in position for mounting on the end of the crankshaft and install rotor throughbolt. Tighten through-bolt just enough to hold rotor in place.

71

ACAUT'oN

the stator assembly is installed can cause rotor

shaft misalignment. Follow recommended ins tallation procedures misalignment.

5.

Carefully lowerthestator assembly overthe rotor

and into position for assembly to the engine. The

rotor end-bearing should fit snuggly into the bearing bore hole.

tor

windings.

against the rotor as it is lowered info position.

6.

Install the four nuts, locking washers, and cap-

screws that secure the stator housing engine-to-generator adapter. Tighten capscrews

to specified torque. Note that each locking

washer is installed under capscrew head.

7.

Tighten the rotor through-bolt to the specified

torque.

8. Hold the drip pan underside of theset and install the threevibration isolator center screws. Tighten the rear (genera-

tor end) center screws to the specified torque.

9.

Secure ground strap to drip tray using acapscrew and two EIT locking washers. Note that ground strap is installed between locking washers to

insure a good electrical connection.

10. Attach the special lifting plate (see Figure the end of the stator housing using four 5/16-18

1

capscrews.

11. Attach a hoist or other suitable lifting device to the lifting plate. Carefully tilt the set back until it is

resting on the drip tray. Remove lifting plate when complete.

12. Remove the piece of wire that is holding the brushes off the slip rings. Check the brushes to

verify that they are centered on the slip rings. If

brushes are not centered, loosen the brush block mounting screws and adjust. Retighten mounting

screws when complete.

13.

Connect the terminal and the

B+

in

place.

of

Tightening the rotor through-

bolt

to

specified torque before

to

avoidany possibility ofshaft

Careless handling

can result in damage

Do

not brush the stator windings

in

position for mounting to the

lead wire to the outboard brush

B-

lead wireto the inboard brush

of

the stator

to

the sta-

to

8-6)

wire

the

to

x

terminal. Install brush block cover and tighten cover mounting screws.

14.

Connect the appropriate lead wires to the charge

resistor, low oil pressure cut-off switch, and

tion coil

15.

Place new intake manifold gaskets on the engine block and install the carburetor and intake manifold assembly. Tighten the intake manifold screws to the specified torque. Connect the pre-

heater tube, crankcase breather hose, fuel lines,

throttle linkage, and choke heaterwires. Refer to

Fuel System Section 6 for detailed assembly procedures.

16. Install the noiseshield,flywheel guard, and transformer cover.

17. Install the generator set in the vehicle and

securely fasten all mounting screws and hard-

ware. Connect the fuel, exhaust, and electrical

systems in reverse order of disassembly. Refer to Set Removal Section

18. Fill crankcase with oil of the recommended clas-

sification and viscosity.

This section covers brush replacement and slip ring service.

Brush

Remove the brush block cover and inspect the

brushes and brush holder for burn marks or other damage. If the brushes appear to be in good condition, usea pieceof wire(modifiedasshown in Figure 8-10) to check for excessive brush wear. Insert the wire into the hole above each brush. Make sure the wire is resting on the brush and not on part spring.

B+

terminal.

5.

BRUSHES

AND

SLIP

Replacement

If

the painted part of the wire is

RINGS

not,

igni-

of

the

brush is

\a

n

I

FIGURE

8-10.

CHECKING

BRUSH

G4V4

WEAR

8-1

1

excessively worn and must be replaced. Always

Redistribution or publication of this document by any means, is strictly prohibited.

replace the brush springs when installing new brushes to insure that proper tension is maintained. Use the following procedure to replace the brushes.

1.

Disconnect the negative battery terminal.

2.

Remove theair cleanercoverand air cleanerfilter element.

3.

Disconnect the Bt (outboard) and lead wires from the brush block terminals.

4.

Remove the brush block mounting screws and lift out the brush block.

5.

Remove brushes and brush springs from holder

and replace with new parts.

6.

Pull

each brush outward from the brush holder and at the same stiff wire through thesmall holes in the base of the

time

SPRING

(-)

battery cable at the

B-

(inboard)

insert (see Figure

BRUSH

8-11)

a

holder. The wire holds the brushes off the slip rings during disassembly.

Install brush block in housing but do not tighten

7.

mounting screws. Remove the wire that is holding the brushes off

8.

the slip rings by pushing the end of the stator housing. Adjust brush block

so

that brushes are centered on the slip rings and

then tighten mounting screws.

Connect the B+ lead wire to the outboard brush

9.

terminal and the B- lead wire to the inboard brush terminal.

Install brush block cover and tighten mounting

10.

screws. Install air filter element and air cleaner cover.

11.

Connect negative

12.

terminal.

Slip

Ring Service

Remove the brush block cover and inspect the slip rings for grooves, pits, or other damage. rings are not in good condition, they may be refinished using a commutator stone. Use the following procedure to service:

it

out through the hole in

(-)

battery cable' to battery

If

the slip

Remove the air cleaner cover and air cleaner

1.

filter. Disconnect the lead wires from the brush block

2.

terminals and then insulate the lead wire ends. Tie the lead wires

to the slip rings. Remove the brush block mounting screws and lift

3.

out the brush block. Remove

4.

K1

switch (normally open) in series between the

S

solenoid. Place a jumper wire between remote connector

5.

plug terminals Press the pushbutton switch to crank the engine

6.

and then release switch as soon as the engine

starts.

Hold commutator stone (Onan

7.

against rotating slip rings until carbon is removed and all grooves or roughness is smoothed out.

K1-S

start solenoid. Connect a pushbutton type

lead wire and the S terminal on the

IliEEEl

injury. Keep vicing slip rings.

to

one side to allow clear access

lead wirefrom theS terminal on the

K1

1

and

3.

tool

#420-0259)

Contact

ery can cause severe personal

hands

wifh

rotating machin-

and fingers clear while ser-

K1-

start

FIGURE

8-11.

4-J

BRUSH

REPLACEMENT

G-1179

8-1

Remove jumper wire from remote connector

8.

Plug. Remove insulating material from ends of brush

9.

lead wires and then install brush block. Follow steps

5

through

section.

10

in Brush Replacement in this

2

TRANSFORMER VOLTAGE

Redistribution or publication of this document by any means, is strictly prohibited.

ADJUSTMENTS

The

generator output voltage may

changing the connections to the transformer secondary taps. This is necessary if the set voltage falls outside the

recommended voltage range when operating at the specified frequency. Use the following procedures to adjust the generator output voltage:

,

1.

Adjust the governor as specified section before making adjustments to the transformer.

2.

Check the generator voltage with the warmed-upset operating at no load and nominal voltage should be

3.

Stop the set and adjust the transformer tap connections as shown in Table the voltage as required.

4.

Repeat the voltage check and continue to make adjustments until voltage is within range specified.

5.

Check the no load and full load voltage and frequency as specified under Governor in Section Voltage and frequency should stay within the limits shown in Table

8-1.

127.5

8-1

to increase or decrease

be

adjusted

in

the Governor

62

hertzfrequency. The

f

4.5

volts

by

AC.

6.

Start the generator set and allow the field voltage with no load applied and then with full load applied. Both readings should fall within a range of

18

to

60

volts

DC. Remove

block cover when test is complete.

Rotor

Test

The rotor can be tested for grounded, open, or shorted windings using an ohmmeter. Figures show the rotor removed from the generator for testing. However, it is possible to test the rotor without removing

it

from the generator. remove the brush block cover. Use astiff wire to hold the brushes Brushes and Slip Rings in this section for the procedures to use for inserting the wire.

Ground

the highest resistance scale. Touch one test prod to the rotor shaft and hold one of the slip rings. indicates the rotor is grounded. Replace a grounded rotor with a new rotor.

off

the slip rings during testing. Refer to

Test: To test for grounds, set the ohmmeter for

To

obtain access to the slip rings,

it

there. Touch the other test prod to

A

reading less than one megohm

test

it

to stabilize. Measure

leads

and

replace

8-12

and

brush

8-13

.

GENERATOR

This section covers the test procedures for the stator, rotor, transformer, and CR4 bridge rectifier.

Field

Voltage

To check the field voltage, remove the brush block

cover and connect a terminals. Connect the positive lead to the terminal and the negative lead to the terminal.

TRANSFORMER TAP CONNECTIONS

VOLTAGE

ADJUSTMENT

To Increase

Standard Setting

To Decrease

Test

DC

TABLE

Voltage

TESTING

voltmeter to the brush block

B+

(outboard)

B-

(inboard)

8-1.

CR4-AC

TO TO

x3

x2

xi

x3

I

X2 x1

I

x3

I

E

1

s1

x4

x5 X5 x5

X6

X6 X6

ES-1558

FIGURE

Open

or

ings, set the ohmmeter for the highest resistance scale. Place test prods on the slip rings as shown in Figure

8-1

2.

Ohmmeter should indicate continuity between slip

A

rings. nection or an open winding. Check the connection between the slip rings and rotor lead wires. Replace rotor if rotor winding is open.

8-12.

TESTING

Shorted Windings

high resistance reading indicates a poor con-

ROTOR

FOR GROUNDS

TeskTo test for open wind-

8-1

3

KW

Redistribution or publication of this document by any means, is strictly prohibited.

6.5

*At 77"

TABLE

8-2

RESISTANCE VALUES FOR ROTORS

STACK LENGTH RESISTANCE*

4.72 in. (120 mm) 10.6 ohm (+lo%)

F

(25"

C)

0

Stator lead B1 from R6-1/H1-1 lead

0

Stator lead

0

Transformer lead

0

Transformer lead H3 from ground

0

CR4-AC2

B2

from ground tab

H1

from ground

lead wire from tap

X5

wire

To test for shorted windings, set the ohmmeter for the

lowest scale. Place the test prods on the slip rings as

shown in Figure 8-12.

A

reading less than the value shown in Table 8-2 indicates shorted windings. Replace a rotor with shorted windings with a new rotor.

n

Insulate or position the lead wire ends

so

they are not touching the generator set housing. Set the ohmmeter for the highest resistance scale and then connect

one test prod to the generator housing. Touch the other test prod (see Figure 8-14) to the leads specified in Table

8-3.

A reading less than one megohm

indicates a ground.

?

H4

@!!!:

ES-1559

FIGURE

8-13

TESTING

ROTOR

FOR

OPENS

OR

SHORTS

Stator/Transformer Test

The stator and transformer can be tested for

grounded or open windings using an ohmmeter.

Testing for shorted windings requires a digital-type

ohmmeter than can read to within

0.01

ohms.

Figures 8-14 and 8-15 show the stator and transformer removed from the generator for testing. However, it is possible to test both components without removing them from the generator. Remove the control panel and transformer cover to obtain access to the specified lead wires during testing.

Ground

Tesf:

To test for grounds, disconnect the

following transformer and stator leads.

Stator lead

S1

from tap

X2

Stator lead TI from CB1 Stator lead T3 from CB2 Stator lead

S2

from CR4-AC1

:

FIGURE

8-14.

TESTING STATOR AND

TRANSFORMER

TABLE

GROUND TEST

FOR

8-3

GROUNDS

FOR

STATORS AND TRANSFORMERS

LEADS LOCATION

Stator Stator Stator

Transformer

I

8-1

4

If

Redistribution or publication of this document by any means, is strictly prohibited.

theTI-T3 lead

is

grounded, the sourceofthe ground

could be either the stator windings or the transformer

primary windings. To isolate, disconnect the transformer primary leads from the stator leads andT4from H4).Touchthe test prod toTl-T3,

(T2

from

H2,

and

H2

H4 to identify the grounded component. Replace a grounded stator or transformer with a new part.

Open orshorted

Windings:

To

test for opens, disconnect the transformer and stator leads as specified in the Ground Test section. Set the ohmmeter for the lowest resistance scale and then connect the test prods (see Figure 8-15) to the leads specified in Table 8-4. The ohmmetershould indicate continuity between

A

lead ends.

high resistance reading indicatesan open

winding.

If the open circuit is between T1

T3 and one

of

the

Or

transformer primary lead wires (H1 or H3), the source of the open could be either the stator windings or the transformer primary windings. To isolate, disconnect the transformer primary leads from the stator leads (T2 from H2 or T4 from H4). Test each winding separately as specified in Table

8

to

locate the source of the open.

Replace the stator or transformer if test indicates an

open winding. To test for shorted windings, use a digital-type ohm-

meter that reads to within 0.01 ohms. Disconnect the transformer and stator leads as specified in Ground Test in thissection. Connect the test prods (see Figure 8-15) to the stator/trans leads as specified in Table8-4.

A

reading less than the value shown in Table 8-4 indi-

cates shorted windings. If the low reading is between Tl-HI or T3-H3, the

of

source

the short could be either the stator windings or the transformer windings. To isolate, disconnect the transformer primary leads from the stator (T2 from H2

T4

and

from H4). Test each winding separately as

TABLE

8-4

RESISTANCE VALUES

FOR STATORS AND TRANSFORMERS

kW STACK TEST RESISTANCE*

LENGTH WINDING

(*

10%)

-

STATOR TRANS

6.5

4.61

IN

(117 mm)

T1 to H1 T3 to H3

62

61 to X1 toX6

0.240 ohm

0.240

ohm

0.049

ohm

0.578 ohm

6-1172-1

FIGURE

TRANSFORMER FOR

8-15.

TESTING STATOR AND

OPENS

OR

SHORTS

specified in Table 8-4 to locate the short. Replace the stator or transformer if test indicates a shorted winding.

Due

to

the low resistance

(or

milliohmmeter

ments.

CR4

Bridge Rectifier Test

equivalent) must be used for accurate measure-

of

the

transformer primary windings, a

The CR4 bridge rectifier can be tested using an ohm-

meter. Remove the two and negative

(-)

Connect one of the test prods to one of the nals and theother test prod

AC

leads and the positive

(+)

leads from the rectifier terminals.

AC

termi-

to

the positive (+)terminal. Observe the reading on the ohmmeter and then reverse the test prod connections. Observe the second reading and compare with the first reading.

A

good rectifier will have a higher reading in one direction. If both readings are the same, the rectifier is defective

and must.be replaced. Repeat test procedure with test prod connected to other prod connected to negative

AC

terminal and with test

(-)

terminal. Replace lead

wires when test is complete.

,

STATOR ONLY

TRANS ONLY

-

*At 77°F (25°C)

T1 toT2 T3 to T4

H4 to

H3

H2 to H1

0.240 ohm

0.009

ohm

0.009

ohm

8-1

5

,

Redistribution or publication of this document by any means, is strictly prohibited.

8-1

,

6

Section

Redistribution or publication of this document by any means, is strictly prohibited.

9

-

Engine

Block

Assembly

GENERAL

The engine block assembly includes the pistons and

connecting rods, crankshaft, camshaft, valves and ters, cylinder heads, lubrication system, timing gears, governor mechanism, bearings, and cylinder block.

Performing any major service on the block assembly will require that thegeneratorset be removed from the coach (see Set Removal in Section gain complete access to the block assembly, the control, generator, and all primary engine systems must also be removed. Refer to the previous sectionsforthe disassembly and removal procedures.

OIL

FILTER

Open the oil drain valve and drain the crankcase oil. Remove the filter (see Figure clockwise with a filter wrench. The low oil pressure cut-off switch is installed in athreaded hole in the filter adapter and may be removed if. required. Loosen the two capscrews that secure the adapter to the engine

block and remove the adapter and gasket. Assembly is the reverse of disassembly. Use a new

adapter gasket and install aligned with the oil holes in the block. Gasket should be installed dry. Coat the threads of each capscrew

with non-hardening sealer and tighten to recommended torque.

AND

so

the two small oil holes are

h

5).

In addition, to

ADAPTER

9-1)

by turning counter-

LOW

OIL

lif-

CYLINDER HEADS

Remove the cylinder heads for cleaning when poor

engine performance is noticed. Use the following

procedures

1. Use a cylinder head bolts or stud nuts and lift off the head.

ACAUTION

engine has cooled before removing heads.

2.

After removing heads, clean out all carbon deposits. Be careful not edges where gaskets fit. The heads are made of aluminum and can bedarnaged by careless handling.

3.

Use new head gaskets and clean both the heads

and the cylinder block thoroughly where the head gaskets rest.

4.

Place a head gasket on the cylinder head and align

the stud holes in the gasket with the stud holes in the cylinder head. While holding the gasket against the cylinder head, carefully install the cylinder head on the engine. slide the gasket over the studs without the cylinder

head behind

5.

Place heads in position and follow head torque

tightening sequenceshown in Figure

tightening all nuts to5ft-lbs

all nuts to 10 ft-lbs (14 Nom), etc., until all nuts are tightened to the torque listed under TorqueSpecifications in Section 4.

to

service.

1/2

inch socket wrench to remove the

Warpage can occur if are removed while hot. Waif until

to

damage the outer sealing

Do

it

or the gasket may tear.

(7

N*m).Then, tighten

the

not attempt to

9-2.

heads

Begin by

FIGURE

9-1.

OIL

FILTER AND ADAPTER

-

LS-1111

'9-1

LEFTCYLINDER

FIGURE

9-2.

RIGHT

CYLINDER

M-1479

CYLINDER HEAD TIGHTENING SEQUENCE

-

-1

Redistribution or publication of this document by any means, is strictly prohibited.

Asbestos gaskets contain fibers

that when airborne harm your

health. Use a respirator when handling and &fa//-

ing gaskets.

6.

After the head nuts have been tightened once,

necessary to tighteneach head nut to thespecified torque a second time. Follow the same sequence shown in Figure

9-2.

Failure to re-torque could

result in a blown head gasket.

7.

Recheck torque before engine has run a total of

hours.

NOTE:

SEE

VALVE

SEE

VALVE

CLEARANCES

'

VALVE

A

NOTE:

.I

it

is

50

TAPPET

RETAINER

VALVE

A

properly functioning valve system is essential for

SYSTEM

good engine performance. All generator sets utilize an L-head type valve design as shown in Figure

Access to the valve system can be obtained by remov-

ing the cylinder heads and the valve covers on top of

the engine.

remove valves (see Figure

A

valvespring compressor must be used to

9-4)

from the cylinder block. Use the following procedures to inspect and service the valve system.

IN

TEXT.

IN

TEXT.

7

.

/

VALVE

ADJUSTING

SCREW

VT-1019 VT-1019

9-3.

FIGURE

9-3.

VALVE SYSTEM

Inspection

Valve Face:

ing, warpage, out-of-round, and carbon deposits (Fig-

ure

Burning and pitting are caused seat tightly. This condition is often caused by hard carbon particles on the seat. It may also be due to weak valve springs, insufficient tappet clearance, warpage, and misalignment.

9-5).

Check the valve face for evidence of burn-

VT-1017

FIGURE

9-5.

VALVE FACE

by

the valve failing to

FIGURE

9-4.

VALVE

SPRING

COMPRESSOR

VT-1018

Warpage occurs chiefly in the upper stem due to its exposure

to

intense heat. Out-of-round wear follows when the seat is pounded by a valve whose head is not in line with the stem and guide.

If

avalve face is burned

or warped, or the stem worn, install a new one.

Too

much clearancein the intakeguideadmitsairand oil into the combustion chamber, upsetting carburetion, increasing oil consumption, and making heavy

9-2

carbon deposits. Carbon prevents heat dissipation.

Redistribution or publication of this document by any means, is strictly prohibited.

Clean metal is a good heat conductor but carbon insu-

lates and retains heat. This increases combustion

chamber temperatures which causes warping and

burning.

Unburned carbon residue gums valve stems and causes them to stick in the guide. Deposits of hard carbon with sharp points projecting become white hot and cause pre-ignition and “pinging”.

ValveSfemSeakAvalvestem seal is used on theintake valve guides. This seal must be replaced each time the

valve is removed.

Stems

and Guides: Always check valve stems and guides for wear as shown in Figure 9-6. Use a hole gauge to measure the valve guide. When clearance

with stem exceeds original clearance by

(0.05

mm), replaceeithervalveorguideorboth, asmay

0.002

inch

be necessary. Always regrind seat to make concentric with the newly installed guide.

+Ad

FIGURE 9-7. VALVE INTERFERENCE ANGLE

VALVE

in a sharp seating surface between the valve and the

top

of

the valve seat (see Figure

9-7).

The valves should not be hand lapped because the sharp contact will be destroyed. This is especially

important where chrome cobalt faced valves and seats are used. Valve faces must be finished in a machine to 44 degrees.

Every valve must have a minimum

of

1/16 inch (1.6

mm) margin, Figure 9-8. If the valve has less margin

than this, it will heat up excessively.

It

will retain that heat during the compression stroke and preignite the mixture, causing loss of power and economy. This

valve is also susceptible to warping and breakage.

.

VT-1020

FIGURE

Spring:

9-6.

VALVE

STEM

AND VALVE GUIDE INSPECTION

Check valve springs for cracks, worn ends, distortion and tension. If spring ends are worn, check valve spring retainer for wear. Check for spring distortion by placing spring on aflat surface next to asquare. Measure height of spring and rotate

to

edge

measure distortion. Check spring tension at

it

against square

the installed height for both the valve open and closed

position using an accurate valve spring tester. Replace any valve spring that is weak, cracked, worn or distorted.

Reconditioning Valves and Valve Seats

The interference angle method of valveseating is used on all generator set engines. With this method, different seat and face angles are used and line contact between the valve face and seat occurs.

Thevalve faceangle is44

is

45 degrees. This l-degree interference angle results

degrees.Theva1veseafangle

7

1/16 INCH

(1.6

FIGURE

mm)

MINIMUM

REFER

TO

FOR

CORRECT

9-8.

VALVE MARGIN

SPECIFICATIONS

DIAMETER

VT-1022

Not all valves can be reconditioned. A badly warped

valve must be replaced because theexcessive grinding

required to make it seat correctly removes the margin.

To

make a valve gas-tight, every trace of pitting must be removed from the valve face and seat. Deeply pitted or cut valves must be replaced because the grinding removes the margin.

Valve seats should be ground with a 45-degree stone and the width 3/64-inch

of

the seat band should be 1/32-inch

(0.79

to

1.2

mm) wide. Grind onlyenough

to

assure proper seating.

it

Place each valve in,

proper location. Check each valve

fora tight seat. Makeseveral rnarksat regular intervals

across the valve face using machinists bluing. Observe

if

the marks rub

off

uniformly when the valve is rotated

part of a turn against the seat. The valve seat should

9-3

contact the valve face evenly at all points. The line

Redistribution or publication of this document by any means, is strictly prohibited.

contact should be at the center

Valve

Guide

Replacement

of

the valve face.

of

Worn valve stem guides can be replaced from inside the valve chamber (aseal is provided behind the intake valve guides only). The smaller diameter of the tapered valve guides must face toward the valve head. Tappets are also replaceable from the valve chamber after first

removing the valve assemblies.

Removal:

Before removing valve guides, use an elect-

ric drill with a wire brush to remove carbon and other

foreign material from top surface

of

guides. Failure to perform this operation may result in damage to the guide bores. Drive the guides out with a hammer and

valve guide driver.

liiBB4I

strike bores Insfallation:

wlfh

Run a small polishing rod with crocus

Driving

the tapped bores. Be careful not to

driver.

out

old guides can damage

cloth through valve guide holes to clean out carbon

ROD

.

and other foreign materials. Place a new gasket on the intake valve guide and coat the outer edge of each

new guide with oil. Place guide, notch up, in cylinder

block and press in until shoulder of guide rests against the cylinder block. installation is shown in Figure

A

suggested method of

9-9.

Valve Seats

Inspect valve seat inserts.

If

seats are loose, cracked, or severely pitted, new inserts must be installed. Remove valve seat inserts using a valve seat removal tool.

Removal;

Remove carbon and combustion deposits

from valve seat. Select the proper size puller

(determined by the inside diameter of the valve seat).

The puller jaws must expand into the cylinder block

at the point where the bottom of the valve seat insert rests on the cylinder block (see Figure

9-10).

Using

the new seat insert asa guide, adjust the pullerdepth.

Position the puller on the valve seat and tighten hex

nut. Clamp cylinder block to a solid bench. Attach slide hammer to puller. Between blows with the slide hammer, tighten the hex nut.

USE

NEW

VALVE

SEAT

ADJUST

PULER

TO

DEPTH

1-It4

IN.

(32

mm)

.-

FIGURE 9-9. VALVE GUIDE INSTALLATION

5

16-18

HEX.

(2

5

16-18THREADED

NUT

REQUIRED)

-

\

5

16

FLAT

(2

REQUIRED)

ROD

WASHER

UT-1023

9-4

WUERLWS

FIGURE

9-10

REMOVING VALVE SEAT

GllU

Replacement:

Redistribution or publication of this document by any means, is strictly prohibited.

After the

old

seat has been removed,

clean carbon or metal burrs from the seat insert

recess. Use a valve seat insert driver and a hammer to install the inserts.

Tappet Adjustment

The engine is equipped with adjustable valve tappets. Adjust the valve clearance only when engine is at

ambient temperature. Proceed as follows:

Insert the pilot of the tool into the valve guide hole in

the cylinder block. Quickly drive in the valve seat

so

insert

that the insert goes evenly to the bottom

of

the recess in the cylinder block. Make certain that the valve seat insert rests solidly on the bottom of the recess around its complete circumference (see Figure

9-1

1).

Thevalveseat must bestaked toassureatightfitand eliminate the danger of its loosening in the bore. Refinish valve seat inserts before installing valves.

Insert valve seat staker in the cylinder block valve guide hole. Rotate thestaking tool until original stake marks. Rotate staking tool another degrees

(1/6

turn). Using a lead hammer, strike the

it

dropsto the

60

staking tool asharp blow to wedge the new valve seat securely in place.

1.

Remove all parts necessary to gain access to

valve tappets.

2.

Remove spark

plugs

to make turning the engine

easier.

3.

Place a socket wrench

on

the flywheel capscrew

and rotate the crankshaft in aclockwise direction

until the left intake valve (viewed from flywheel

end) opens and closes. Continue turning the

crankshaft until the

TC

mark on the flywheel is

lined up with theTC mark on thegear cover. This

should place the left piston

(#1)

at the top of its compression stroke. Verify that the left intake and exhaust valves are closed and there is no pressure on the valve lifters.

4.

Clearances are listed under Specifications in

Section

2.

For each valve, the gauge should just

pass between the valve stem and valve tappet (see

9-12).

Figure

FIGURE

9-11.

CHECK

THIS

FOR

INSERTING

INSERTING NEW VALVE SEAT

SURFACE

BURRS BEFORE

SEAT

VT-1025

9-5

FIGURE

5.

To correct the valve clearance, turn the adjusting

9-12.

VALVE CLEARANCE ADJUSTMENT

screw as needed to obtain the right clearance.

The screw is self-locking.

6.

To adjust valves on the right cylinder, turn engine one complete revolution and again line up mark on the flywheel and the

TC

mark on the gear cover. Then follow adjustment procedure given for left cylinder.

7.

Replace all parts removed. Tighten all screws securely. Torque manifold bolts.

VT-1026

314

Redistribution or publication of this document by any means, is strictly prohibited.

GOVERNOR

IN.1

ROLL

ROTATE

GOVERNOR

SO

THAT

FITS

METAL

HOLE

BUSHING

ROLL

INTO

LINED

OR

PLASTIC

IN

FIGURE

CUP

THE

CUP

,’

9-13.

GEAR COVER ASSEMBLY

GEAR COVER

Remove the flywheel key and gear cover mounting screws. Gently tap the gear cover with a plastic-faced hammer to loosen

When installing thegear cover, makesure that the pin in the gear cover engages the nylon lined (smooth) hole in the governor cup. Turn the governor cup that the nylon lined hole is at the three o’clock position. Use a small amount governor cup in position. The rounded side of the governor yoke must ride against the governor cup. Turn the governor arm and shaft clockwise as far as possible and hold in this position until the gear cover is installed flush against the crankcase. Be careful not

to damage the gear cover oil seal.

it

(see Figure 9-13).

of

grease to assist in holding

so

GOVERNOR

engine. If necessary, the engine may be tilted up

ARM

SHAFT

IF

FEELER

ENTER HOLE

BALL

HAS

WILL

1/2 IN.

(13

FALLENOUT,

mm)

VT-1027

to

install the cup and flyballs. Put the flyballs between

the spacer arms and install the cup on the center pin,

Lock the cup in place with the snap ring.

The camshaft center pin extends out 3/4-inch (19

mm) from the end of the camshaft. This distance provides an in and out travel distance of 7/32-inch

(5.6

mrn) forthegovernorcup, as illustrated. Hold the

cup against the flyballs when measuring. If the dis-

tance is less, the engine may race, especially at no

load. Remove the center pin and press in a new pin

3/4

IN.

Wmm)

,

.

Refer

to

Oil Seals in this section if replacing the gear

cover oil seal.

GOVERNOR CUP

With the gear cover removed, the governor cup can

be taken off after removing the snap ring from the camshaft center pin, Figure while sliding the cup off.

Replaceanyflyball thatisgrooved orhasaflatspot. If

the arms

damaged, remove the spacer by splitting with a chisel. Use a press to install a new spacer on the camshaft gear. The governor cup must spin freely on

the camshaft center pin without excessive looseness

or wobble. If the racesurface of the cup is grooved or rough, replace it with a’new one.

The governor cup and flyballs are easily installed when the camshaft assembly is removed from the

of

the ball spacer are worn or otherwise

9-14.

Catch the flyballs

9-6

FIGURE

9-14.

U

GOVERNOR

VT-1028

CUP

the specified amount.

Redistribution or publication of this document by any means, is strictly prohibited.

Do

not hammer

the

new

into place or it will be damaged. The camshaft center pin cannot be pulled outward nor removed without

damage.

will

If

the

center

not hold the flyballs.

TIMING

GEARS

extends

out

too far,

AND CAMSHAFT

the

cup

If replacement of either the crankshaft gear or the camshaft gear becomes necessary, it is recommended that both gears be replaced.

To remove the crankshaft gear, first remove the snap ring and retainer washer; then attach the gear pulling ring using two

screws (Figure

9-15).

No.

10-32

Tighten the screws alternately until both are tight.

Attach a gear puller to the puller ring and remove the gear.

The camshaft and gear are removed

as

an assembly. Before removing the camshaft and gear assembly, remove the cylinder head and valve assemblies. Then remove the operating plunger for the breaker points

and tappets.

LUBRICATION SYSTEM

All generator set engines use an oil pump to provide a constant flow of oil to theengine parts.Theoil supply collects pump pick-up cup.

oil pressure. Drain the

base and always usea new gasket when replacing the

oil base.

Oil

Theoil pump (Figure9-16) ismounted on the frontof

the crankcase behind the gear cover and is driven by

the crankshaft gear. The inlet pipe and screen

assembly is attached directly to the pump body. A discharge passage in the cover of the pump registers with a drilled passage in the crankcase. Parallel passages distribute oil to the front main bearing, rear

main bearing and pressure control bypass valve.

in

Pump

the

oil

base where

A

it

is

picked up by the oil

by-pass valve is used to control

oil

before removing the oil

OIL

PUMP

PICK-UP

CUP

.

CRANKSHAFT

THESE

MARKS

WHEN

MUST

INSTALL-

GEARS.

VT-1029

FIGURE 9-15.

TIMING

GEAR

REMOVAL

Each timing gear is stamped with

so

The gearteeth must mesh

that these marks exactly

ALIGN

ING

TIMING

AND

INSTALLATION

“0”

near the edge.

coincide when the gears are installed in the engine.

When installing the camshaft gear and shaft assem-

bly, be sure that the thrust washer

is

properly

in

place behind thecamshaft gear.Then install thecrankshaft retaining washer and lock ring.

FIGURE

CRANKCASE

ON

9-16.

OIL

LEFT

PUMP

TURNED

SIDE

ASSEMBLY

LS-1109

Circumferential grooves in the main bearings supply oil to the connecting rod bearings through drilled

passages from each main journal. A drilled passage connects the front main bearing oil supply to the front camshaft bearing. The oil overflow from the bypass valve furnishes lubrication to the camshaft drive gears.

Normal oil pressure should be

30

psi

(207

kPa) or

higher when the engine is at normal operating temper-

ature. If pressure drops below this value at governed speed, inspect the oil system for faulty components.

Check theoil pump thoroughlyforworn parts.

Oil

the

pump to prime it before reinstalling. Except for

gaskets and pick-up cup, the component parts of the

pump are not available individually. Install a new pump assembly if any parts are worn.

Oil

By-Pass

Valve

The by-pass valve (located to the right and behind gear cover, Figure

9-17)

controls

oil

pressure by

allowing excess oil to flow directly back to the crank-

9-7

HEX

Redistribution or publication of this document by any means, is strictly prohibited.

CAPSCREW

FLAT

WASHER

PISTON

The piston assembly consists of the piston, piston

rings, piston pin, connecting rod assembly, and bearing. After removal from the engine, all parts must be carefully inspected for damage and wear before

replacing.

ASSEMBLY

Removal and Disassembly

Remove carbon from top of cylinder bore and check

9-18)

for a ridge. Remove ridge (see Figure ridge reamer before attempting piston removal.

with a

FIGURE

case. Normally the valve begins to open about 30 psi

(207

kPa).

The valve is non-adjustable and normally needs maintenance.To determine if abnormal (high or low) oil pressure is caused by improper valve operation inspect as follows:

1.

Remove gear cover and under governor arm.

Remove spring and plunger with a magnet or

2.

magnetic tool. Determine proper valve operation

3.

thespring and plungeraccording to the following

measurements. Plunger Diameter..

Spring

3/8-24

Free Length., Load

.

when compressed to

,

.

. , .

9-17.

OIL BY-PASS VALVE

x

1

in. capscrew located behind

by

,

.

. . .

.

0.3105 to 0.3125 in. (7.89 to

. .

.

. . .

.

1.00

inch (25.4 mm)

.. .

.. . . .

.2.6-+0.2 Ibs

0.500

(11.6f0.9

inch (12.7 mm)

no

checking

7.94

mm)

N)

Improper damage

1-1

ton land or rings. Remove wear ridge before remov-

ing the piston.

FIGURE

To

remove the piston and connecting rod assemblies,

turn the crankshaft until a piston is at the bottom of the

stroke. Remove the nuts from theconnecting rod bolts. Lift the rod bearing cap from the rod and push the rod

and piston assembly out the top of the cylinder with the

handle end of a hammer. Be careful not to scratch the crankpin or the cylinder wall when removing these parts.

Mark each piston and rod assembly respective cylinders after overhaul. Keep connecting rod bearing caps with their respective rods.

Forcing the piston from before reaming can damage fhe pis-

9-18.

use

of a ridge reamer can

fhe

cylinder bore.

fhe

REMOVING WEAR RIDGE

so

they can be returned to their

cylinder

CT-1058

4.

Check the valveseat and clean away anyaccumulation of metal particles which could causeerratic valve action. Verify that the valve seat is concentric with the larger diameter valve bore.

Clean plunger and spring in parts cleaning sol-

5.

vent and install.

The pistons are fitted with two compression rings and

one oil control ring. Remove these rings from the pis-

ton using a piston ring spreader as shown in Figure

9-1

9.

Mark each piston

assembled on the piston from which it was removed.

to

make sure the rod will be

9-8

.

Remove

Redistribution or publication of this document by any means, is strictly prohibited.

the

piston pin retainer from each side and

push the pin out.

.

FIGURE 9-19. REMOVING PISTON RINGS

Cl-1059

Remove dirt and deposits

from

the piston pin surfaces

with an approved cleaning solvent. Clean the piston ring grooves with a groove cleaner or the end of a piston ring filed to a sharp point (Figure

9-20).

Care

must be taken not to remove metal from the groove

sides.

I

lZE%Eil

Using a caustic cleaning solvent wire

brush

for

cleaning pistons wii/

or

cause piston damage. Use only parts cleaning solvent.

When cleaning the connecting rods in solvent, include the rod bore. Blow out all passages with low pressure compressed air.

Inspection

The following covers inspection procedures for pistons and connecting rods.

Piston Inspection:

the ring lands, skirtsand pin bosses. Check forwearat the ring lands using a new ring and feeler gauge as shown in Figure9-21. Replace the piston when the side clearance of the top compression ring reaches inch

(0.20

mm).

Inspect the pistons for fractures at

0.008

FIGURE 9-20. CLEANING RING GROOVES

CT-1060

9-9

FIGURE 9-21. CHECKING RING

CT-1061

LAND

CYLINDER

Redistribution or publication of this document by any means, is strictly prohibited.

WALL

FIGURE

vv

9-22.

NEW RING IN WORN RING GROOVE

CT-1062

Improper width rings or excessive ring side clearance can result in ring breakage. New rings in worn ring grooves don't have good cylinder wall contact (Figure

9-22).

Replace pistons showing signs of scuffing, scoring, worn ring lands, fractures or damage from pregnition.

Connecting

Rod

Inspection:

Replace connecting rod bolts and nuts with damaged threads. Replace connecting rods with deep nicks, signs of fractures, scored bores or bores out inch

(0.05

mm)

of

round more than

0.002

Use a new piston pin to check connecting rod for

wear.

A

push

fit

clearance is required and varies from engine to engine. dry rod pin bore as a result

If

a new piston pin falls through a

of

its own weight, replace

the rod or bushing as required.

Pisfon

cracked, scored, or out

Pin Inspection:

(0.05

mm).

Replace piston pins that are

of

round more than

0.002

inch

CT-1063

FIGURE

9-23.

PISTON CLEARANCE MEASUREMENT

ring gap by placing each ring squarely in its cylinder, at a position corresponding to the bottom

of

its travel

(Figure9-24).Thegap between theendsofthe ring is

given in Dimensions and Clearances in Section 3. The practice of filing ring ends to increase the end

gap is not recommended. If the ring end gap does not

meet specifications, check for the correctness of ring

and bore sizes.

mm)

undersize will reduce the end gap 0.003 inch

(0.08

mm).

Standard size rings may be used on mm) oversize pistons. Rings that are

0.030 and

A

cylinder bore that is

0.040

inch

(0.25,

0.51,

0.76

0.001

0.005

0.010,

and

inch

(0.03

inch (0.13

0.020,

1.02

mm)

oversize are to be used on corresponding oversize

of

pistons. Rings

TOP

on one side, or identified in some other manner.

the tapered type are usually marked

Install these rings with the identification mark toward

the closed end of the piston.

Bearing Inspection:

breaks, pitting and wear. Replace bearing inserts that are scored, have the overlay wiped out, show fatigue failure, or are badly scratched. If bearings appear to be serviceable, check them for proper clearance.

Piston Clearance

Proper piston tolerances must be maintained for satisfactory operation. Use a micrometer to measure the piston diameter at the point shown in Figure9-23. When the cylinder bore

Block in this section), subtract the piston diameter from the cylinder bore diameter to obtain the piston to cylinder wall clearance. Refer to Dimensions and Clearances in Section clearance.

Fitting Piston Rings

Before installing new rings on the piston, check the

Inspect bearings for burrs,

is

measured (see Cylinder

3

for the recommended piston

9-1

0

FIGURE

9-24.

CHECKING RING

PISTON

CYLINDER

FEELER

RING

GAGE

GAP

IN

BORE

CT-1064

\

Redistribution or publication of this document by any means, is strictly prohibited.

-

THIN

FIGURE

SIDEOFCAP

9-25.

ROD

MARKS-ROD#2

CAP ALIGNMENT

-

1

-

cT-1065

1.

Turn

crankshaft to position

bottom of its stroke.

2.

Lubricate piston assembly and inside of cylinder. Compress rings with in

Figure

3.

Position the piston and rod assembly in the cylinder block with the connecting rod oil hole toward the camshaft.

4.

Tap piston down into bore with handle end of hammer until connecting rod isseated on journal. Check bearing clearance before proceeding to step section).

5.

Lubricate the rod bearing journal and install the connecting rod cap. Tighten connecting bolts to specified torque.

9-26.

install bearing insert in rod.

#5

(see Rod Bearing Clearance in this

rod

bearing journal

a

ring compressor

as

at

shown

rod

Piston

Lubricate all parts with clean engine oil. Position the piston on the connecting rod. Install the piston pin.

The piston pin isa full-floating type, and must be kept

in place in the piston with two lock rings (one at each side). Install the two lock rings and ensure the lock rings are properly in place before installing the piston

and connecting rod in the engine.

Install the rings on the piston beginning with the oil control ring. Use a piston ring spreader to prevent twisting or excessive expansion of the ring. Com-

pression rings are marked with a dot or the word “top” on oneside of the ring to indicate which side faces the top of the piston. Unmarked piston rings can be installed either way. The oil control ring has an expander: install the expander first and then close

until the expander ends butt together. Locate the expander gap

Assembly

180

Installation

degrees from the ring gap.

The bearing cap must be tapped several times to

properly align ance varies on the journal if this is not done. Install the remaining pistonsand rods in thesame manner. Crank the engine by hand to see that all bearings are free.

Rod

Bearing Clearance

1.

Mark all parts original positions; and wipe all parts clean of any oil or grease.

2. Place a piece of the correct size Plasti-Gage across the full width of the bearing cap about 1/4-inch

3.

Install the bearing cap and tighten to the specified torque. cap is in place.

4.

Remove the bearing cap and leave the flattened Plasti-Gage on the partto which it adheres. pare the widest point of the flattened Plasti-Gage with the graduations on the envelope (see Figure 9-27) to determine the bearing clearance.

3’

it

with the connecting rod. Clear-

so

they can be installed in their

(6

mm) off center.

Do

not rotate the crankshaft after the

0

Com-

‘X-

@

FIGURE

lnsfalling

ton assembly, the raised lines (witness marks

Figure 9-25) on the rods and caps must be aligned.

Also,

side of the cap. When assembled on the crankshaft,

the thin side of the cap should be next to the cylinder block. The rod and cap stamped #2 should be installed next to the bearing plate.

Piston

in

note that the connecting rod bolt is offset to one

9-26.

INSTALLING

Cy/indec

PISTON

When installing the pis-

-

see

9-1

1

FIGURE

9-27.

MEASURING BEARING CLEARANCE

CRANKSHAFT

Redistribution or publication of this document by any means, is strictly prohibited.

To remove the crankshaft, loosen the rear bearing

plate screws and remove the bearing plate, gasket,

thrust washer, and shims. Turn the crankshaft

so

the

crankthrow is aligned with the notch in the rear open-

ing of the crankcase. Carefully slide the crankshaft

out of the crankcase.

Inspection

Inspect the rod and main bearing journals. If they are

worn or scored and cannot be smoothed out by pol-

ishing, either the journals should be reground to use one of the standard undersize bearings or the crankshaft should be replaced. Remove only as much metal as is required to restore the journal surface while maintaining the recommended bearing clearance.

Whenever making major repairs on the engine, always inspect the drilled passages of the crankshaft.

to

Clean them

assure proper lubrication

remove any foreign material and to

of

the connecting rods.

Installation

Lubricate the front and rear main bearings with

engine oil. Use oil or gear lubricant to hold the front thrust washer in place against the engine block. The flat side of the thrust washer goes against the block.

Checking

Endplay

After tightening two rear bearing plate nuts (or capscrews) to the specified torque, check the crankshaft endplay at the point shown in Figure

9-28

using a feeler gauge. Lightly tap the front of the crankshaft with a plastic-faced hammer to take up the freeplay. Refer to Dimensions and Clearances Section 3for the recommended crankshaft endplay. If necessary, remove the rear bearing and plate and add or remove shimsas required. Install theend plateand tighten all nuts (or capscrews) to the specified torque. Make sure the shim and thrust washer are in place, and recheck crankshaft endplay. Verify that the crankshaft turns freely without binding.

Position the crankshaft

so

the crank throw is aligned with the notch at the rear of the crankcase and install the crankshaft. Make sure the front thrust washer did

not slip out

Place the oil seal loader

of

place during installation.

on

the oil seal guide and

driver and insert into the rear bearing plate. Remove

the seal guide and driver leaving the loader

in

the bearing plate. The loader prevents the seal from being cut on the crankshaft keyway during installa-

tion of the rear bearing plate.

Use oil or gear lubricant to hold the shim(s) and rear thrust washer in position on the rear bearing plate

(see Figure

9-32).

The shim goes against the bearing plate and the flat surface of the thrust washer goes against the shim.

in

Place the bearing plate gasket

position on the block, making sure the oil hole on the back of the block is exposed. Install the rear bearing plate and fasten with two nuts (or capscrews) tightened to the specified torque. Make sure the rear thrust washer and shim(s) did not slip out of place during installation. The crankshaft should turn freely by hand.

MEASURE

(REFER

FIGURE

ENDPLAY

TO

DIMENSIONS

AND

CLEARANCES)

9-28.

CYLINDER

HERE

CHECKING

BLOCK

CT-1068

ENDPLAY

The cylinder block is the main support for all other

basic engine parts. Crankshaft and camshaft are supported

by

the block, assuring alignment of the

crankshaft and cylinder bores.

9-1

2

Cleaning

Redistribution or publication of this document by any means, is strictly prohibited.

After removing pistons, crankshaft, cylinder heads, etc., inspect block for cracks and extreme wear. If

block

is

still

serviceable,

f

0

Ilows:

1.

Scrape all old gasket material from block.

prepare

it

for

cleaning

as

Remove oil by-pass to allow cleaning solution to contact inside of oil passages.

2.

c

Remove grease and scale from cylinder block by agitating in a bath of commercial cleaning solution or hot soapy washing solution.

3.

Rinse block in clean hot waterto remove cleaning

solution.

Inspection

When rebuilding the engine, thoroughly inspect block for any condition that would make it unfit for further use. This inspection must be made after all parts have been removed and block has been tho-

roughly cleaned and dried.

1.

Make a thorough check for cracks. Minute cracks may be detected by coating the suspected area

with a mixture of

25

percent kerosene and

75 percent light motor oil. Wipe the part dry and immediately apply a coating of zinc oxide (white lead) dissolved in wood alcohol. If cracks are present, the white coating will become discolored

at the defective area. Always replace a cracked cylinder block.

2. Inspect all machined surfaces and threaded holes. Carefully remove any nicks or burrs from machined surfaces. Clean out tapped holes and

clean up any damaged threads.

3.

Check top of block for flatness with a straight edge and a feeler gauge.

Cy/inder

Bore

Inspection:

Inspect cylinder bores for

scuffing, scratches, wear, and scoring. If cylinder

bores are scuffed, scratched, scored, or worn, they must be rebored and honed for the next oversize piston.

When the appearance of cylinder bores is good and there are noscuff marks, check cylinder bore for wear or out of roundess as follows:

1.

Check cylinder bore for taper, out-of-round, and wear with acylinder bore gauge, telescope gauge or inside micrometer. These measurements should be taken at four places, top and bottom of

piston ring travel, parallel and perpendicular to axis of crankshaft.

2. Record measurements taken at top and bottom of piston travel as follows (see Figure 9-29).

-

A. Measure and record as

B.

C.

D.

E.

TOP

END

OF

CYLINDER

RING

‘WEAR

AREA

BOTTOM

FIGURE

OF

9-29.

CYLINDER

RING

TRAVEL

METHODS

BORE DIAMETER

OF

MEASURE

“A”

the cylinder bore

CT-1090

diameter (parallel to crankshaft) near the top

of cylinder bore where greatest amount of

wear occurs. Also measure and record as

“B”

cylinder bore

diameter (parallel to crankshaft) at the bot-

tom

of

piston travel.

Measure and record as

“C”

cylinder bore

diameter (perpendicular to crankshaft) near the top of cylinder bore where greatest amount of wear occurs.

Also measureand record as “D”cylinder bore diameter (perpendicular to crankshaft) at the

bottom of piston travel. Reading “K’subtracted from reading“6”and

reading

“C”

subtracted from reading

“D”

indicates cylinder taper.

9-1

3

If cylinder taper exceeds

0.003

inch

(0.08

mm), rebore and hone cylinder to the next oversize.

F. Reading

Redistribution or publication of this document by any means, is strictly prohibited.

reading “B” compared to reading “D” indicates whether or not cylinder is out-of-round.

If out-of-round exceeds0.003 inch the cylinders must be rebored and honed to the next oversize. A reboring machine is used when going to oversize pistons. The following

repair data covers honing to oversize by use of a hone.

Reboring

Rebore and hone engine whenever cylinder bore is worn, damaged, out-of-round, or if cylinder taper exceeds specifications. be resized to the smallest standard oversize diameter at which diameters should then be obtained by honing.

it

/BCAUTIONI

face that may should be done only by qualified service personnel who are careful in fheir

After boring to the correct oversize cylinder bore

dimension, piston and ring clearance should be appropriate. There is no need to adjust or“fit” pistons and rings.

When reboring cylinders, take the following precautions:

1.

Make sure cutting tool is properly ground before using it.

2.

Be sure top of engine block is smooth and deposit free.

Clean base of boring bar before bar is set up.

3. Deposits under boring bar will cause

the cylinder will be distorted after boring.

4.

Make

an

Then hone cylinder bore to the specified oversize.

“A”

compared to reading “C” and

(0.08

mm),

the

Cylinder

A

worn cylinder bore should

will clean up. The final finish and bore

If boring bar

it will produce a rough cylinder sur-

not

clean up even when honed. Boring

is

operated incorrecfly,

work.

it

to

tilt,

and

initial rough cut, followed bya finish cut.

Honing Cylinders [Using Precision Hones)

Refer

to

hone manufacturer’s recommended grit size

20

to

40

or

RMS.

heavy-

250

to

to produce specified surface finish of

Too

rough of a finish will wear out the rings and too

smooth of a finish can retard piston ring seating.

1, Position block solidly for either vertical or horiz-

ontal honing. duty drill which operates at approximately

450

r/min.

2.

Follow hone manufacturer’s instructions for the use of oil or lubricant on stones. cants with a dry hone.

3.

Insert hone in bore and adjust stones to fit snugly to the narrowest section. When adjusted correctly, the hone should not shake or chatter in

Use

either a drill press

Do

not use lubri-

cylinder bore but will drag freely up and down

when hone is not running.

4.

Connect drill to hone and start drill. Feel out bore for high spots, which cause an increased drag on

in

stones. Move hone up and down short overlapping strokes about

minute. Usually bottom of cylinder must be worked out first because takes a uniform diameter, move hone up and

down all the way through cylinder bore.

5.

Check diameter of the cylinder regularly during

honing. A dial bore gauge is the easiest method,

but a telescoping gauge can be used. Check size at six places in bore; measure twice at top, middle and bottom at 90-degree angles.

6.

Crosshatch formed by the stones should form an

included angle of achieved by moving the rotating hone (250 to450

r/min) up and down in cylinder bore about times per minute.

7.

Clean cylinder bores thoroughly with soap, water, and clean rags. A clean white rag should

not become soiled on wall after cleaning is com-

plete. Do not use a solvent or gasoline, since they wash

oil

from the walls but leave metal particles.

8.

Dry crankcase and coat

Deglazing Cylinder

Deglaze the cylinder bores if thereare no scuff marks

and no wear or out of round beyond specifications

before installing new rings. Deglazing gives a fine finish but does not enlarge cylinder diameter, original pistons with new rings may still be used.

The reason for deglazing a cylinder is to provide cavities to hold oil during piston ring break-in.

1.

Wipe cylinder bores with a clean cloth which has been dipped in clean, light engine oil.

2.

Use a brush type deglazing tool with coated bristle tips to produce a crosshatch pattern in the cylinder bore.

3. The deglazing tool should be driven by a slow speed drill. Move deglazing tool up and down cylinder enough to obtain a crosshatch pattern as shown in Figure 9-30.

(10

-1

bores

after deglazing will not remove abrasives from fhe walls. Abrasives

not

removed from engine will rapidly wear rings, cylinder walls, and bearing surfaces lubricated parts.

4.

Clean cylinder bore thoroughly with soap, water, and clean rags. Continue cleaning until a clean white rag shows no discoloring when wiped through cylinder bore.

Bores

to

12

Never use gasoline cial cleaners

it

is smaller.

23

degrees. This can be

it

with oil.

complete strokes) rapidly

to

or

honing. These solvents

bore with

40

times per

As

cylinder

40

so

the

in

or

commer-

clean cylinder

of

all

?

b

9-1

4

hole(s)

Redistribution or publication of this document by any means, is strictly prohibited.

at least

in

the bearing bore. The

1/2

open.

oil

passage

must

be

PRODUCE CROSS HATCH SCRATCHES

FOR FAST RING SEATING

FIGURE

9-30.

CROSSHATCHING

AVOIDTHIS FINISH

CT-1091

BEARINGS

Removal of the camshaft or crankshaft bearings

of

requires complete disassembly

combination main and cam bearing removal tool and

a press to drive out the bearings. Support the casting

to avoid distorting or damaging the bearing bores.

Camshaft Bearings

Replacement camshaft bearings are precision type

and do not require line reaming or line boring after

installation. Coat the bearing with lubricating oil.

Position the front bearing

so ing isaligned with the oil hole (see Figure9-31) in the block. Position the rear bearing is aligned with the breaker point plunger hole in the

top of the block.

the engine. Use a

the oil hole in the bear-

so

the elongated slot

Rear Bearing:

bearing driver and a press

Use the combination main and cam

to

install the rear main

bearing. Push the bearing into the bearing plate from

9-32)

to

the

the inner side (see Figure

depth allowed

by the flange on the driver.

REAR BEARING END PLATE

LOCK

IOLES

BEAR

DO

PRECISION TYPE-

-

Front

Bearing:

FIGURE 9-32. REAR BEARING

Locktite Bearing Mount is used when

NOT LINE REAM OR BORE

M-1475

installing the front bearing (see Figure 9-33). Use the

towelette furnished with the bearing kit

of

outside

the bearing and the bearing bore in the

to

clean the

IN-

BEAiNG

FIGURE 9-31. CAMSHAFT BEARINGS

BORE

M-I474

Use the combination main and cam bearing driver and a press to install the front and rear cam bearings. Push in the bearings to the depth allowed by the flange on the driver.

Crankshaft Bearings

New crankshaft main bearings are precision type

or

which do not require line reaming

line boring after

installation. They are available in standard size,

0.002,0.010,0.020 or

For

putting

in

always align the oil hole(s) in the bearing with the

0.030

inch undersize.

either the front

or

rear main bearing,

oil

NOTE:

Do

not

add additional

thrust washer when replac-

ing front

bearing.

e

9

DO

FIGURE

PRECISION TYPE-

NOT

LINE

9-33 FRONT

BORE

FRONT MAIN

BEARING BORE

/

FRONT

MA

IN

OR

REAM

OR

BORE

BEARING

-

BE

A

R

IN

c

8-1476

9-1

5

block. Apply the Locktite Bearing Mount

Redistribution or publication of this document by any means, is strictly prohibited.

to

the mat-

ing surfaces of the bearing and bearing bore. Allow

three to four minutes for drying.

'

Breathing vapor from fowelette and

prolonged contact with skin can

cause severe personal injury. Be sure area

is

well- ven fila fed.

Use the combination main and cam bearing driver and a press to install the front bearing. Push in the

bearing to the depth allowed by the flange on the

driver. Wipe

off

any

excess Locktite and allow one

hour for hardening at room temperature.

Engines shipped from the factory have separate thrust washers

and main bearings for both front and rear

replacement is one piece bearing (with attached thrust washer) as

shown in Figure this front bearing.

9-33.

Do

not add an additional thrust washer to

OIL

SEALS

of

engine. Front bearing

Remove the rear bearing plate to replace the rear oil seal. Remove the gear cover to replace the front oil seal. Use an oil seal remover to pry

out

the front or

rear oil seal.

Lubricate the lips

of

the replacement seal with a light coating of grease before installing the rear bearing plate or gear cover. This provides initial lubrication until engine oil reaches the seal. Refer to Crankshaft in this section for the rear bearing plate installation procedures. Refer to Gear Cover in this section for

the gear cover installation procedures.

--

Use an oil seal guide and driver to press or drive the rear seal into the rear bearing plate until it bottoms against the shoulder of the plate (see Figure 9-34). Press or drive the front oil seal into the gear cover until it is mounting face

0.97

f

0.02 inch (24.6

of

the cover.

GEAR

COVER

f

USE

0.5

mm)

GREASE

THIS

CLEANED

SEALING

FORE

I

from the

IN

MOUNTING

OF

GEAR

COVER

0.97

?

0.0'2

(24.6

?:

0.5

SURFACE

OF

COMPOUND

INSTALLING

FACE

INCH)

mm)

SHOULDBE

ALL

OLD

SEAL.

.

IE-

E

THIS

SURFACE

CLEANED

SEALING

FORE

INSTALLING

SHOULD

OF

ALL

OLD

COMPOUND

SEAL

BE

BE-

rfi

GEAR

COVER

OIL

SEAL

FIGURE

9-34.

9-16

REAR

BEARING

OIL

OIL SEALS

'

SEAL

PLATE

M-1477