Onan E125V, E140V Service Manual

ONAN E125 V, E140V ENGINE SERVICE MANUAL

Table of Contents – Page 1 of 3

SAFETY PRECAUT I O NS

GENERAL BATTERIES PROTECT AGAINST MOVING PARTS FUEL SYSTEM EXHAUST SYSTEM EXHAUST GAS IS DEADLY KEEP THE UNIT AND SURROUNDING AREA CLEAN

SUPPLEMENT 965-1053

PURPOSE SERVICE MANUAL 965-0764 REVISIONS CARBURETOR (BEGINNING SPEC E)

SECTION 1. GENERAL INFORMATION SECTION 2. SPECIFICATIONS SECTION 3. DIMENSIONS AND CLEARANCES SECTION 4. ASSEMBLY TORQUES SECTION 5. ENGINE TROUBLESHOOTING

SECTION 6. MAINTENANCE PERIODIC MAINTENANCE SCHEDULE ENGINE INSPEC TION AIR CLEANER AND ELEMENT WRAPPER OIL CHANGE OIL FILTER CHANGE COOLING VALVE CLEARANCE SPARK PLUG

SECTION 7. LUBRICATION OIL CHANGE OIL FILTER CHANGE OIL LEVEL CHECK OIL PRESSURE OIL PRESSURE RELIEF VALVE OIL PUMP DISASSEMBLY ROTOR LOBE CLEARANCE OUTER ROTOR AND PUMP BODY CLEARANCE ROTOR AND COVER CLEARANCE ASSEMBLY

SECTION 8. ELECTRICAL IGNITION SYSTEM SPARK PLUG IGNITION COIL IGNITION TIMING FLYWHEEL ALTERNATORS ALTERNATOR OUTPUT TESTS

ONAN E125 V, E140V ENGINE SERVICE MANUAL

Table of Contents – Page 2 of 3

SECTION 9. FUEL GASOLINE CARBURETOR DISASSEMBLY INSPECTION/SERVICE ASSEMBLY CO ADJUSTMENT IMPULSE FUEL PUMP INSPECTION/SERVICE FUEL PUMP REMOVAL FUEL PUMP INSTALLATION LPG FUEL SYSTEM GOVERNOR ADJUSTMENTS

1. GOVERNOR LEVER ADJUSTMENT

2. IDLE SPEED ADJUSTMENTS

3. CHOKE ADJUSTMENT

4. SPEED CONTROL CABLE ADJUSTMENT AIR CLEANER FOAM WRAPPER ELEMENT PAPER ELEMENT

SECTION 10. STARTING RECOIL STARTER 110 VAC STARTER SOLENOID SHIFT START ER SOLENOID ARMATURE COMMUTATOR AND MICA STARTER BODY BRUSHES OVERRUNNING CLUTCH

SECTION 11. ENGINE BLOCK ASSEMBLY

INTRODUCTION ENGINE DISASSEMBLY/ASSEMBLY

SUGGESTED DISASSEMBLY ORDER SUGGESTED ASSEMBLY PROCEDURE OPERATION COMPRESSION TEST FLYWHEEL DISASSEMBLY SERVICE/INSPECTION ASSEMBLY

VALVE COVER

ROCKER ARM DISASSEMBLY INSPECTION/SERVICE ASSEMBLY CYLINDER HEAD DISASSEMBLY ASSEMBLY

ONAN E125 V, E140V ENGINE SERVICE MANUAL

Table of Contents – Page 3 of 3

SECTION 11. ENGINE BLOCK ASSEMBLY –CON’T

VALVE SYSTEM

TAPPETS DISASSEMBLY INSPECTION/SERVICE VALVE STEM AND VALVE GUID E C LE AR ANC E: VALVE GUIDE REPLACEMENT: ASSEMBLY VALVE SPRING: VALVE FACE AND SEAT GRINDING INSPECTION/SERVICE VALVE SEAT WIDT H: VALVE SEAT CUTTING: VALVE CLEARANCE: OIL BASE DISASSEMBLY ASSEMBLY GOVERNOR BALANCING SHAFTS DISASSEMBLY OIL BASE BEARING TO SHAFT CLEARANCE: ASSEMBLY CRANKSHAFT AND CAMSHAFT DISASSEMBLY INSPECTION/SERVICE CRANKSHAFT JOURNAL: CAMSHAFT LOBE HEIGHT: OIL BASE BEARING TO CAMSHAFT CLEARANCE: ASSEMBLY

COMPRESSION RELEASE SYSTEM

PISTON, PISTON PIN, RINGS, CONNECTING ROD DISASSEMBLY PISTON INSPECTION PISTON INSPECTION: PISTON PIN HOLE INSIDE DIAMETER: PISTON PIN OUTSIDE DIAMETER: PISTON RING AND RING GROOVE CLEARANCE: CONNECTING ROD SMALL END INSIDE DIAMETER: CONNECTING ROD TO CRANKSHAFT JOURNAL OIL CLEARANCE: CONNECTING ROD SIDE CLEARANCE: ASSEMBLY CYLINDER BLOCK CLEANING INSPECTION REBORING THE CYLINDER HONING CYLINDER (USING PRECISION HONES) DEGLAZING CYLINDER BORE BALL BEARINGS OIL SEAL

El25V,

El40V

Elite

Series

Printed

in

U.S.A.

965-0764

Spec

A-C

6-94

Safety

Precautions

Before

operating the engine,

read the Operator's Manual and

become familiar with it and the equipment.

Safe and efficient

operatlon can be achieved only

If

the equipment

Is

properly operated and maintained.

The following symbols, found throughout this manual, alert you to potentially dangerous conditions to the operator, service personnel, or

the

equipment.

Thls

symbol

warns of immediate hazards

whlch will result in severe personal Injury or death.

WARNING

This symbol refers to a hazard or unsafe practice whlch can result in severe personal Injury or death.

CAUTION)

This symbol refers to a hazard

or

unsafe practlce whlch can result In personal Injury or product or property damage.

Fuels, electrical equipment, batteries, exhaust gases and moving parts present potential hazards that can result in severe personal injury. Take care in following these recommended procedures.

All

local, state and federal codes should be

consulted and complied with.

WARNING

Thls engine is not designed or Intended for

use

In any type of aircraft.

Use

of this engine In aircraft can result In engine failure and cause severe personal injury or death.

GENERAL

Provide appropriate fire extinguishers and install them in convenient locations. Use an extinguisher rated ABC by NFPA.

Make sure that all fasteners on the engine are secure and accurately torqued. Keep guards in position over fans,

driving belts, etc.

If it is necessary to make adjustments while the engine is running, use extreme caution when close to hot exhausts, moving parts, etc.

Used engine oils have been identified by some state and federal agencies as causing cancer or reproductive toxicity. When checking or changing engine oil, take care not

to

ingest, breathe the fumes, or contact used oil.

Do not work on this equipment when mentally or physically fatigued, or after consuming any alcohol or drug that makes the operation of equipment unsafe.

BATTERIES

Before starting work on the engine, disconnect batteries to prevent inadvertent starting of the engine. Disconnect

negative cable first.

DO NOT SMOKE while servicing batteries. Lead acid batteries give

off

a highly explosive hydrogen gas which can

be ignited by flame, electrical arcing or by smoking. Verify battery polarity before connecting battery cables.

Connect negative cable last.

PROTECT AGAINST MOVING PARTS

Do

not wear

loose

clothing in

the

vicinity

of

moving parts, such as PTO shafts, flywheels, blowers, couplings, fans, belts, etc.

Keep your hands away from moving parts.

FUEL SYSTEM

DO NOT

fill

fuel tanks while engine is running.

DO NOT smoke or use an open flame in the vicinity of the engine or

fuel

tank. Internal combustion engine fuels are

highly flammable. Fuel line must be of steel piping, adequately secured, and

free from leaks. Piping at the engine should be approved flexible line. Do not use copper piping for flexible lines

as

copper

will

work harden and become brittle enough to

break.

Be

sure all fuel supplies have a positive shutoff valve.

Benzene and lead, found in some gasoline, have been identified by some state and federal agencies as causing cancer or reproductive toxicity. When checking, draining or adding gasoline, take care not to ingest, breathe the fumes, or contact gasoline.

EXHAUST SYSTEM

Exhaust products of any internal combustion engine are

toxic and can cause injury, or death

if

inhaled. When operating the engine in a confined area, make sure the ventilation system is operating properly.

DO NOT use exhaust gases to heat a compartment.

Make sure that your exhaust system is free of leaks. Make sure that exhaust manifolds are secure and are not warped by bolts unevenly torqued.

EXHAUST GAS

IS

DEADLY!

Exhaust gases contain carbon monoxide, a poisonous gas that can cause unconsciousness and death. It is an odorless and colorless gas formed during combustion of hydrocarbon

fuels.

Symptoms of carbon monoxide poisoning are:

Dizziness

Vomiting

Headache

0

Muscular Twitching

Weakness and Sleepiness

Throbbing in Temples

If

you experience any of these symptoms, get out into fresh air

immediately, shut down the unit and do not

use

it until it has

been inspected.

The best protection against carbon monoxide inhalation is proper installation and regular, frequent inspections of the complete exhaust system. If you notice a change

in

the sound or appearance of exhaust system, shut the unit down immediately and have it inspected and repaired at once by a competent mechanic.

KEEP THE UNIT AND SURROUNDING

AREA

CLEAN

Make sure that oily rags are not

left

on or near

the

engine.

Remove all unnecessary grease and

oil

from the unit. Accumulated grease and oil can cause overheating and subsequent engine damage and present a potential fire hazard.

E-8

Supplement

Date:1-95

lnsert

Title: Number

PURPOSE

965-1053

with-

El

25V/E140V

(Date):965-0764(6-94)

Service

Manual

This Supplement transmits the revisions to the Service Manual necessary for covering that the nameplate on a Spec emissions regulations for

E

engine will have the statement:

ULGEengines.”

“This

engine meets

Spec

€engines. Note

1995-1998

California

To satisfy California emissions regulations Spec E engines have internal engine modifications and precisionmanufactured carburetors with tamper-resistant fuel mixture jets. installing the optional high-altitude jet (Figure 9-3a), fuel mixture adjustments should not should the carburetor be overhauled. Instead, a malfunctioning carburetor (see

It

should therefore be noted that, other than

be

attempted. Nor

Engine Troubleshooting)

should be replaced.

California users should note that unauthorized modifications or replacement of fuel, exhaust, air intake, or speed control system components that affectengineemissions are prohibited by California regulations and that the optional high-altitude main jet is not intended for use in California. Modification, removal or replacement of the generator set label Is also prohibited.

SERVICE

1.

Insert this cover sheet behind the front cover of the manual.

2.On

3. On

Page

1-1

of the manual add the following note at the bottom

for

fuel and engine oil recommendations and the Periodic Maintenance Schedule.”

Page

9-1

of the manual add “(Does not

MANUAL

Apply

965-0764

to

Spec E and Later)”

REVISIONS

of

the page: “See the Operator’s Manual

to

the subheadings “Disassembly”

and “Inspection/Service”.

4.

On

Page

42

of

the manual add “(Does Not Apply

to

the heading

5.

insert the attached page

Attachment: Page

“CO

9-2-1.

Adjustment”.

(9-2-1)

between

Page

to

Spec E and Later)” to the subheading “Assembly” and

9-2

and Page

9-3

of the manual.

Page 1 of

1

SECTION

TITLE

Safety Precautions inside cover

PAGE

1

2

3

4

5

6

7

8

9

10

General Information 1-1 Specifications 2-1 Dimensions and Clearances 3-1 Assembly Torques 4-1 Engine Troubleshooting 5-1 Maintenance Lubrication Electrical Fuel Starting 10-1

Block

Engine

Assembly 11 -1

INCORRECT SERVICE OR REPLACEMENT OF PARTS CAN RESULT IN SEVERE PERSONAL INJURY AND/OR EQUIPMENT DAMAGE. SERVICE PERSONNEL MUST BE QUALIFIED PERFORM ELECTRICAL AND/OR MECHANICAL SERVICE.

WARNING

TO

Section

1

General Information

INTRODUCTION

This manual provides specific mechanical and electrical information needed by engine mechanics for troubleshooting, servicing, or overhauling the engine.

Use the separate parts manual for parts identification and for establishing their proper location on assemblies. The parts manual contains detailed exploded views of each assembly and the individual piece part numbers and their proper names for ordering replacement parts.

The illustrations and procedures presented in each

section apply to the engines listed on the cover. The air cleaner side of the engine is the front end. Right and left sides are determined by viewing the engine from the front.

If

a major repair

trained and experienced mechanic perform the re-

pair and torque values are within the specified tolerances.

Use the table of contents for a quick reference to the

separate engine system sections.

The troubleshooting guide is provided as a quick

reference for locating and correcting engine

problems.

The wiring diagram shows how the electrical com-

ponents are interconnected.

The

overhaul procedures for step by step removal,

see

Engine

or

an overhaul is necessary, have a

that all dimensions, clearances and

BIock Assembly

section contains major

disassembly, inspection, repair, and assembly of the engine components.

Use only Genuine Onan replacement parts to pro-

vide quality and the best repair and overhaul

results. When ordering parts, always use the complete model and spec number as well serial number shown on the nameplate.

TABLE

1. Model letter designation.

2.

3.

4. Engine fuel. (Example N

5.

6.

1-1.

ENGINE MODEL IDENTIFICATION

BHP

rating. Add a decimal one digit in from the

=

right end. (Example 140 Designation

shaft).

=

Dual fuel)

D Factory code for designated optional equip-

ment, Specification (spec letter) which advances with

factory production modifications.

if

(V = vertical shaft,

any.

14.0)

=

gasoline,

H = horizontal

as

L = LP,

the

INCORRECT SERVICE

JURY AND

ELECTRICAL AND/OR MECHANICAL SERVICE.

OR

EQUIPMENT DAMAGE. SERVICE PERSONNEL MUST BE QUALIFIED

OR

REPLACEMENT

OF

PARTS CAN RESULT IN SEVERE PERSONAL IN-

TO

PERFORM

\

Section

2.

Specifications

These specifications are in customary parentheses.

SPECIFICATION MEASURE Number Bore mm 84.2 84.2

Stroke mm 70.0 70.0

Displacement

Compression Ratio Power at

Oil Capacity Litres 1.7

of

Rated

With

Cylinders 1

Speed

Fitter (Quarts) (1.75) (1.75)

(3600 rpm)

U.S.

units of measure with approximate metric equivalents following in

2-1.

TABLE

SPECIFICATIONS

OF

UNIT

(in) (3.31)

(in) (2.76) (2.76)

Cm3

(in3)

kW 9.3 10.4

(BW (1 2.5)

El

25V

389 389

(23-7)

8.5 to 1 8.5 to

SERIES

El

4OV

1

(3.31)

(23-7)

(1

4.0)

1

-7

1

Cylinder Compression kPa

(Psi)

483

(70

or

more

more)

2-1

Section

All

measurements given at room temperature of approximate inch measurements in parentheses. Measurements are for standard size parts. Refer to the headings for notes

3.

about

Dimensions and Clearances

70°F

(21

"C).

All

measurements are given in millimeters with

which specs are covered,

if

the spec is not listed the dimensions cover all specs.

CYLINDER BLOCK

Cylinder Bore Taper

TABLE

3-1.

DIMENSIONS AND CLEARANCES

DESCRIPTION

____-

ALLOWABLE

I

LIMIT

CAMSHAFT SPEC

Lobe- Height, Diameter Over Nose

El25 Intake

El25 Exhaust

E140 Intake

El40 Exhaust

End Clearance

Oil Base Bearing Clearance

A

AND B

CAMSHAFT BEGIN SPEC C

Lobe Height, Diameter Over Nose

El25 Intake

El25 Exhaust

34.31 34.46

(1.351) (1.357)

34.62 34.77

(1.363) (1.369)

35.18 35.33

(1.385) (1.391)

35.18 35.33

(1.385) (1.391)

0.10

(0.004)

.0.01

(0004) (-0020)

34.23

(1-348)

34.53

(1-359)

0.20

(0.008)

0.05

34.55

(130)

34.85

(1.372)

33.81

(1.331)

34.12

(1.343)

34.68

(1.365)

34.68

(1-365)

0.25

0)

(0.01

.0.08

(.0031)

33.73

(1-328)

34.03

(1-340)

El40 Intake

El40 Exhaust

End Clearance

Journal Bearing O.D. Oil Base Bearing Clearance

-_---

35.09

(1-381)

35.09

(1.381)

0.10

(0.004)

17.975

(.7077)

0.01

(.OOO4)

3-2

35.41

(1.394)

35.41

(1.394)

0.20

(0.008)

17.990

(.7083)

0.05

(.0020)

34.59

(1.362)

34.59

(1.362)

0.25

0)

(0.01

17.93

(.

7059)

0.08

(.0031)

TABLE

3-3.

DIMENSIONS AND CLEARANCES

DESCRlPTlON

FACTORY SPECIFICATION

MIN MAX

PISTON SPEC

A

AND

B

Piston Skirt

O.D.

90

deg

to Pin,

26.5

from

Top

of Piston

84.09

84.1

2

(3.31

1)

(3.31 2)

.25

Oversize

84.34 84.37

(3.320) (3.322)

50

Oversize

84.59 84.62

(3.330) (3.331)

Pin Bore

I.D.

PISTON BEGIN SPEC C

Piston

Skirt

O.D.

deg

to

Pin, from

Top

of

Piston

26.5 90

20.000

20.01

0

(0.7874) (0.7878)

84.09 84.1

2

(3.31

1

)

(3.31 2)

.25

Oversize

84.34 84.37

(3.320) (3.322)

50

Oversize

84.59 84.62

(3.330) (3.331)

Pin Bore

I.D.

20.004 20.01 2

(0.7876) (0.7879)

PISTON PIN SPEC A AND

B

Piston Pin

O.D.

20.000

20.005

(0.7874) (0.7876)

Clearance in Piston

.005

.010

(.0002) (0.0004)

Clearance in Connecting

Rod

.010 .025

(0.004)

(0.001

0)

PISTON PIN BEGIN SPEC C

Piston Pin

O.D.

20.000

20.005

(0.7874)

(0.7876)

Clearance in Piston

.....................-.001 .012

(.OooO)

(0.0005)

Clearance in Connecting

Rod

.010

.025

ALLOWABLE

LIMIT

20.020

(0.7882)

20.022

(0.7883)

19.990

(0.7870)

0.30

(0.001 2)

(0.001

4)

.035

19.990

(0.7870)

0.03

(0.001 2)

.035

3-3

TABLE

3-4.

DIMENSIONS AND CLEARANCES

DESCRIPTION

PISTON

RINGS

Top Compression Ring Thickness

Second Compression Ring Thickness Top Compression Ring to Ring Groove

Clearance Second Compression Ring to Ring Groove

Clearance

Top Compression Ring End Gap

Second Compression Ring End Gap

Oil Ring Side Rail Gap

INTAKE VALVE

Valve Stem

O.D.

Valve Guide

I.D.

Valve Stem to Guide Clearance

El

25V

Valve Lash

El40V

Valve

Lash

Face Angle

INTAKE VALVE SEAT

Seat Width Seat Angle

EXHAUST VALVE

Valve Stem

O.D.

Valve Guide

I.D.

Valve Stem to Guide Clearance

FACTORY SPECIFICATION

1.47

(.058)

1.47

(.058)

0.03

(0.001)

0.03

1.49

(.059)

1.49

(.059)

0.08

(0.003)

0.08

(0.003)

0.25

0.51

(0.010) (0.020)

(0.01

0)

(0.020)

(0.01

5)

(0.055)

0.25

0.51

0.38 1.40

6.960

6.975

(0.2740)

(0.2746)

7.000

7.015

(0.2756)

(0.2762)

0.03

0.06

0.075

0.15

45"

(0.001) (0.002)

(-003) (-006)

7.940

7.960

(0.31 26)

(0.31 34)

8.000

8.015

(0.3150)

(0.31 56)

0.04

0.08

(.003)

ALLOWABLE

LIMIT

1.42

t.056)

1.42

(-056)

0.13

(0.005)

0.13

(0.005)

1.oo

(0.039)

1.oo

(0.039)

1.80

(0.071)

(0.004)

0.25

(0.01

0)

(0.01

0)

1.7

(.067)

DESCRIPTION

TABLE

3-5.

DIMENSIONS AND CLEARANCES

EXHAUST VALVE

E125V Valve Lash E140V Valve Lash

Face

Angle

(cont)

EXHAUST VALVE SEAT

Seat Width

SeatAngle

VALVE SPRINGS INTAKE AND EXHAUST

A

SPEC

Valve Spring Free Length (Approx.) Valve Spring Length

Valve

Valve Open

Spring Load (Valve

AND B

Closed

Length)

0.075 (-003)

0.1 5

(-006)

45"

43.5

(1.71)

32.6

(1.28)

23.2

(0.91

)

5.67 kg 6.62 kg

(1 2.5

Ib)

(1 4.6

Ib)

0.25

(0.01

0.25

(0.01

1.7

(0.067)

0)

Spring Load (Valve Open Length)

VALVE SPRINGS INTAKE AND EXHAUST

BEGIN SPEC C

Valve Spring Free Length Approx Valve Spring Length

Valve

Valve Open

Spring Load (Valve Closed Length)

Spring Load (Valve Open Length)

Closed

11

-52 kg 13.43 kg

(25.4

Ib)

43.5

(1.71)

32.6

(1.28)

23.2

(0.91)

12.6 kg 14.6 kg

(27.7

Ib)

26.4 kg

Ib)

(58.2

(29.6

(32.1

28.4 kg

(62.7

3-5

Ib)

10.21 kg (22.5

Ib)

24.9 kg

(55

Ib)

-"--

DESCRIPTION ROCKER ARM

Rocker Arm Inside Diameter

Rocker Arm Shaft O.D.

Rocker Arm to Shaft Clearance

-__.__I-

LUBRICATING SYSTEM

Engine Oil Pressure

At Idling

At

3300

rpm

Rotor Lobe Clearance

Outer Rotor to Pump

Body

Clearance

Rotor and Cover Clearance

IGNITION

SYSTEM

Spark

Plug Gap

Ignition Timing (BTDC) Not Adjustable Ignition Unit Core to Rotor Magnet

Clearance (Air Gap)

ELECTRICAL SYSTEM

Commutator

O.D.

Difference

of

Commutator

O.D.'s

_--

Armature's Shaft to Bushing Clearance

Mica Undercut

BALANCE

SHAFT

End Clearance (Both Shafts).

AND

CLEARANCES

FACTORY SPECIFICATION

MIN MAX

-_I___-__

12.000

12.018

(0.4724) (0.471 8)

11.973 11.984

(0.4714

(0.471 8)

0.016

0.045

(0.0006)

(0.001 8)

-I_----*

3.0 psi

or

more

14.0 psi or more

0.15 or

less

(

0.006

or less)

0.12 0.19

(0.005)

(0.007)

0.02

0.09

(0.001) (0.004)

0.89 0.89 1.02

(0.035)

(0.040)

23"

0.50

(0.020)

28.0)

Less than' 0.05

(Less than 0.002)

0.02 0.07

(0.001) (0.003)

(1.102)

0.45

0.75

(0.01

8)

(0.030)

0.10

0.20

(0.004) (0.008)

3-6

ALLOWABLE

0.15

(0.0059)

4.0

psi

0.20

(0.008)

0.25

(0.010)

27.00

(1.063)

0.016 (0.41)

0.20

(.008)

0.20

(0.008)

0.25

(0.01

0)

Section

4.

Assembly

Torques

The torque values listed in Table

4-1

have been Tighten all studs,

nuts

and capscrews as specified determined for specific applications. The engine to keep them from working loose. Refer to the Parts assembly torques given here

will

provide proper Manual for the location of washers and capscrews.

tightness without danger of stripping threads.

All

threads must be clean,

rust

free

and lightly

lubricated.

TABLE

4-1.

ASSEMBLY TORQUES

DESCRIPTION

Conn

Rod

Bolts

Oil

Base

Bolts Oil Pump Cover Screws Oil Pump Screen Cover Oil Drain Plugs

Oil

Base

Pressure Line Plugs LOPCO or Pipe Plug Adapter Filter Head Oil Filter

Oil Indicator Cap Cy1 Head

Bolts

NO. 1-5 Bolts No.

6

Flange

Bolt

Valve Lash Adj

Nut

Valve Cover Bolts

Spark Plug Air Deflector Bolts

Pulse Pump to Deflector Pulse Pump Spud

Int Elbow to Cy1

Hd

Screws

Air Cleaner Pan to Air

Deflector

Carb. to Int Elbow Knob-Inner Air CLnr Knob-Outer Air Clnr Cy1 Air Hsg

Bolt

Exhaust Elbow Bolts Muffler Bolts Starter Bolts Alternator Stator Screws Stator Wire Clamp

Screw

Flywheel Nut Ignition Coil

Bolt

Blower

Hsg

Bolts

Voltage

Reg

Screws

Chaff Screen Bolt Stationary Guard Bolt

Recoil Starter Cup Screw Recoil Starter Bolts Control Plate

Stud

Control Plate Pivot Bolt Nut-Control Plate Stud Governor

Arm

Nut

Throttle Cable Clamp Screw

Nuts

M8x44 24-27 M8x

50

16-22 M6x 14 M6x 14

3/8”

NPT

114" NPT 7-11 1/8” NPT

3/416"

24-30

1.5-2

7-11 7-11 7-11

7-11

M10 42-50

M8x50 16-22

M7 7-11

M6 x 25 7-11

M8x

11-20

10-24 M8x 16

M6x 10 7-11

#10 2.3-2.8

18-20 OIL BASE TORQUE 12-16-

58 5-8 Torque

'A"

twice.

Toque bolts in

clockwise

direction

starting

with "A"

SEQUENCE

118" NPT

M8x

50

114" x .50"

M6x

85

M6x 10

M8

M8x

45

M8X95 M8x

40

M6x

25

M6x 14

M18 M6 x 27 M6x20

114"

x

.50”

M6x 10 M6x

20

M8x 16 M6x 12

M8 M8 M6 M6

1032"

7-11

11-16

6.7-8.1 10-15

Not

Specified

7-11

11-20 16-22

10-15 10-15

122-138

10-15

7-11

6.7-8.1

7-11

1.4-2

24-30

7-11 11-16 11-16

7-11

8.1-10.9

1.4-2

5-8 58

58

18-22

3/41 Turn after gskt

1.1-1.5(13-18LB*IN) contacts

base

Toque

in

sequence shown.

after

others

are

done.

Tighten

every

other bolt

until

all

bolts

are tightened.

Retorque

the

first bolt

twice.

31-37 Two

bolts

outside

valve

cover

12-16

(#2

&

#4)

To

be

retorqued

5-8

58 7-18 8-15

58

1.7-2.1 (20-25 LB-IN

C-1138

5-8 8-12

5-6 (60-72 L

7-11

Not

Specified

58 8-15 8-15

12-16 12-16

7-11

90-102

7-11 7-11

5-8

5-6 (60-72

LB_IN

58

1-1.5 (12-18 LB*IN)

18-22

5-8 8-12

5-8

68

a12

1-1.5 (12-18 LB-IN

Tighten

twice

(1-2-1)

contacts element

1-1/2-2 turns after

cover

CYLINDER HEAD

TORQUE SEQUENCE

4-1

5-1

Section

6.

Maintenance

PERIODIC MAINTENANCE SCHEDULE

Keep an accurate logbook of maintenance, service,

and operating time: Follow a regular schedule of inspection and service, based on operating hours.

Use the factory recommended Periodic Maintenance Schedule (based on favorable operating

conditions) to serve as a guide to get long and efficient engine life.

Regular service periods are recommended for nor-

mal service and operating conditions. is in an application with extreme temperatures, severe duty cycles, etc., service at more frequent intervals.

TABLE

If

the engine

6-1.

PERIODIC MAINTENANCE SCHEDULE

Neglecting routine maintenance

performance and reduced engine life.

WARNING

parts

can

equipment damage. Service personnel must qualified to

cal service.

WARNING Accidental

can result in severe personal Injury or death. DIsconnect the negative battery cable and

spark

controls, or associated equipment.

Incorrect service or replacement of

result in severe personal Injury and/or

plug

perform

wire

electrical and/or mechani-

starting

before servicing the engine,

will

result in poor

of the engine

be

Air

Cleaner Element and

1

Check for fuel leaks.

2-

Perform more often when running under severe operating conditions.

3-

Required for initial break-in

4-

Required for initial

With

100

engine running, visually and audibly check exhaust system for leaks.

only.

hours,

200

hour interval thereafter.

X

X2

X

ENGINE INSPECTION AIR CLEANER AND ELEMENT WRAPPER

Do

Check the fuel lines and fittings for leaks. start engine until leaks are repaired.

WARNING

in severe personal injury

Breathing exhaust gases can result

or

death. Inspect the

not the and

exhaust system audibly and visualiy for leaks

Refer to

service procedures.

daiiy and repair leaks immediateiy.

Inspect the exhaust system for cracks and run the engine to check for leaks. Repair problems before

be

allowing the engine to Examine the air cleaner components for damage, Refer to

proper fit, etc. Repair or replace components as service procedures. necessary.

Check-the oil level with the engine ment on a level surface.

the full mark on the dipstick, add oil of the proper

(see

viscosity reaches the

with the oil level

mark.

Oil Change

full

mark.

below

used.

off

and the equip-

If

the oil level is at or below

section) until the level

Do

not operate the engine

the add or above the

full

Refer to service procedures.

Refer

to

and

service

Refer to

service

Air

Cleaner,

in section

assembly

OIL CHANGE

Oil Change,

in section

OIL FILTER CHANGE

Oil Filter Change,

COOLING

Flywheel,

in section

VALVE CLEARANCE

valve

system,

in

section

procedures.

SPARK PLUG

Spark

procedures.

Plug,

in section

9,

for disassembly,

procedures.

7,

for inspection and

in

7,

for inspection and

11,

for inspection and

for

8,

for inspection and

inspection

Section

A

pump driven by one vides pressure lubrication of the connecting rod journal through drilled passages in the crankcase and crankshaft. An oil hole in the crank arm provides spray lubrication of the piston, cylinder walls, and other crankcase components. The lubrication

system includes an oil pressure relief valve and full-

flow oil filter (Specs

sible by removing a cover in the oil base.

WARNING

parts can result in severe personal injury and/or

equipment damage. Service personnel must be qualified to perform electrical and/or mechanical service.

Improper service or replacement of

7.

B

and C). The oil pump is acces-

Lubrication

of

the balancer shafts pro-

the drain plug and remove the plug (open the drain cock). Replace the drain plug (close the cock) when the oil has stopped draining. Refill with oil meeting the API classification

having the proper viscosity for the ambient temper-

ature. See Table

mended for severe duty use and minimum oil consumption at temperatures above

TABLE

7-1.

OIL

SG,

SG/CD,

7-1.

Straight weight oil is recom-

VISCOSITY

RECOMMENDATIONS

or

32" F (0"

SG/CE

C).

and

WARNING

can result in severe personal injury or death. Disconnect the negative battery cable and spark controls, or associated equipment.

WARNING

hot oil, which can cause severe personal injury.

Do

not check oil while the engine Is running.

WARNING

if

it

comes in contact with skin. Wearprotective

clothing and keep fingers and hands clear when

draining oil.

WARNING

have determined that used engine oil is carcino-

genic and causes reproductive toxicity. Take

care not to breathe, ingest or come Into contact with used engine oil.

CAUTION

sumption, high operating temperatures, and oil foaming. Do not overfill crankcase.

Run the engine until it is thoroughly warm before draining the oil. Stop the engine, place

Accidental starting

plug

wires while servicing engine,

OIL

CHANGE

Crankcase pressure can blow out

Hot crankcase oil can cause burns

Some States or federal agencies

Excess oil can cause high oil con-

of

the engine

a

pan under

OIL

FILTER

WARNING

if

it comes In contact with skin. Wearprotective clothing and keep fingers and hands clear when draining oil.

CAUTION

sumption, high operating temperatures, and oil foaming. Do not overfill crankcase.

Spin the oil filter element

the filter mounting surface and make sure a gasket

is

inserted in the new element. Apply a thin film new oil to the gasket. Spin the element down by hand until the gasket just touches the mounting sur- face. Then add another tighten. Fill with oil to the run the engine until it is warm. Check for oil leaks. Check oil level.

Hot crankcase oil can cause burns

Excess oil can cause high oil con-

CHANGE

off

and discard it. Clean

1/2-3/4

FULL

turn.

Do

mark and start and

of

not over-

7-1

OIL LEVEL

CHECK

WARNING

Crankcase pressure can blow

out

hot oil, which can cause severe personal injury

Do

not check oil while the engine

is

running.

Correct

oil

level in the crankcase is required to insure proper lubrication and prevent saturating the air cleaner paper element with oil.

Always check the oil with the engine stopped and on a level surface. When checking the oil level, always screw the oil

fill

cap into the dipstick tube until it

lightly seats on the oil

fill

tube.

The

oil

fill

cap has a rubber seal that seats on the oil

fill

tube. Inspect this rubber seal and replace

if

dam-

aged, stretched or missing.

OIL PRESSURE

Refer to Figure

7-1.

Install an engine

oil

pressure

tester in the oil

base

as shown. The engine

will

have

an oil pressure switch

or

a

1/8”

pipe plug the tapped hole. Start the engine. After warming up, measure the idle and maximum speed oil pressure.

If

oil pressure is not as specified in Dimensions and

Clearances, the following may

be

the cause:

engine

oil

level

low

clogged

oil

strainer

defective

oil

pump clogged oil gallery excessive clearance between crankshaft

jour-

defective relief valve or spring

nal and connecting rod

Determine cause of

low

oil pressure and

correct

as

necessary.

7-2

FIGURE

7-1.

CHECKING

OIL

PRESSURE

OIL

PRESSURE RELIEF VALVE

Refer to Figure

valve is accessible only after the oil base has been

removed. The check ball and spring are retained by a retainer ring. On valve is removable form the outside by removing

the retaining bolt.

Wash all components in solvent and allow them to dry. Inspect the components for damage and wear.

Replace parts

7-2.

On Specs B and C the oil relief

Spec

A

the oil pressure relief

as

necessary.

SPECS B AND C

I

?

WARNING

Most parts cleaning solvents are

flammable and can cause severe personal In-

jury

or death

If

used

Improperly. Follow the

manufacturer's recommendations when clean-

ing parts.

Lubricate the oil relief valve with oil before assembling. On Specs and drive it right down to the shoulder of the counter

B

and C use a new retaining ring

FIGURE

7-2.

SPEC

A

OIL

RELIEF VALVE COMPONENTS

7-3

OIL

PUMP

Disassembly

Refer to Figure

7-3.

Remove the capscrews holding

the oil pump cover to the

oil

base. Separate the in-

ner and outer rotor.

Rotor

Lobe Clearance

Refer to Figure

7-4.

Measure the clearance

be-

tween the inner rotor

lobes

and the outer

rotor

lobes

with a feeler gauge.

If

clearance is not as specified

in

Dimensions

and

Clearances,

replace

oil

pump.

FIGURE

7-3.

OIL

PUMP DISASSEMBLY

-I

*-----

FIGURE

74.

MEASURING ROTOR LOBE

CLEARANCE

Outer Rotor and Pump Body Clearance

Refer

to

Figure

7-5.

Measure the clearance

be-

tween the outer rotor and the pump body with

a

feeler gauge.

If

the clearance is not as specified in

Dimensions and Clearances,

replace the oil pump.

Rotor and Cover Clearance

Refer to Figure

7-6.

Place a strip of plastigauge on

the rotor face. Install the pump cover and tighten the

screws to that specified in

ASSEMBLY TORQUES.

Remove the cover carefully and measure the width of the plastigauge with the table provided.

If

clear-

ance is not as specified in

DlMENSlONS AND

CLEARANCE,

replace oil pump.

Assembly

Prime each part with oil before reassembling.

Fol-

low

torques given in

ASSEMBLY TORQUES

when

tightening hardware. Check

oil

pressure after serv-

icing or replacing any lubrication system compo-

nent.

FIGURE

7-5.

MEASURING OUTER

ROTOR

TO

PUMP

BODY

CLEARANCE

-__;--.--

FIGURE

7-6.

MEASURING ROTOR TO COVER

CLEARANCE

7-5

Section

8.

Electrical

~WARNING~

parts

can result in severepersonalinjury and/or equipment damage. Service personnel must qualified to cal service.

Refer to Figure high voltage pulse that fires the spark plug each rev-

olution of the engine when the magnet in the rim the flywheel passes across the pole faces of the

ignition coil. The ignition circuit may include a

throttle plate switch and/or a

switch.

incorrect service or replacement of

be

perform

IGNITION

electrical

and/or mechani-

SYSTEM

8-1.

The ignition coil produces a

low

oil pressure cutout

of

Spark

REMOVAL:Clean the area around the spark plug fore removing spark plug. Remove the spark plug from the cylinder head.

Inspection/Service

as recommended

Schedule

spark plugs that show signs of fouling erosion.

Installation

gap to that specified in

ances.

Never

head.

Tighten spark plug to the torque specified in

SEMBLY

Plug

it.

Remove the spark plug lead from

Check or replace spark plugs

in

the

Periodic Maintenance

(located in Operator's Manual). Replace

or

Refer to Figure

assemble

TORQUES.

a

cold spark plug into a hot cylinder

8-2.

Set spark plug

Dimensions and Clear-

be-

electrode

AS-

FIGURE

8-1

TYPICAL

IGNITION

SYSTEM

8-1

FIGURE

8-1.

SPARK.PLUG GAP

Ignition

Coil

Spark Test:

If

the engine will not start conduct a

spark test as follows:

WARNING

Gasoline and LPG vapors are ex-

tremely flammable and can cause severe Injury

or

death if ignited. Make certain there are no gasoline or LPG fumes present before conducting the spark test.

WARNING

ignition voltage can cause severe

personal injury.

Do

not touch Ignition compo-

nents while conducting the spark test.

1.

Obtain a test plug or new plug of the same type as specified for the engine. Disconnect the

spark plug cable from the engine spark plug, connect it to the test plug and ground the side of the test plug to bare metal on the engine block.

2.

Crank the engine while looking at the spark

If

the spark

is

strong, the ignition system is

good.

If

the spark

is

weak, check for and readjust the

clearance between the coil and flywheel.

Also

check the condition of the spark plug cable.

If

tion coil.

If

there

is

no

spark,

bypass the kill switch

(throttle plate switch) and oil pressure switch (if provided) with a jumper to bare metal on the engine block.

If

there is now spark, replace the

faulty switch.

If

there is no spark, replace the

ignition coil.

plug.

the cable appears damaged, replace the igni-

Measuring Coll/Flywheel Clearance:

Refer to

Figure

8-2.

Measure the clearance between each

pole face of the coil and the magnet on the flywheel.

If

the clearance is not as specified in

Dimensions

and Clearances,

loosen the

two

coil mounting

screws and adjust to specifications.

Ignition

Timing

Ignition timing is set at the factory and is not adjustable. The solid state ignition components are not adjustable and require no routine maintenance.

If

.the engine’s timing is not close to that specified in

Dimensions and

Clearances

check the key

be-

tween the flywheel and crankshaft.

FLYWHEEL ALTERNATORS

When the engine is equipped with a

12

VDC starter

motor a permanent magnet flywheel alternator and

electronic voltage regulator may

be

provided for

battery charging. Refer to Figure

8-3.

The flywheel will have three to six permanent magnets depending

on

the output capacity.

See

Section 10. Starting

regarding starter

motor

service.

When the engine

is

equipped with a

110

VAC starter motor and/or recoil starter a permanent magnet flywheel alternator and

full

bridge rectifier may be provided for the customer DC interface (clutch, hour meter, etc.). Refer to Figure

8-4.

The

110

VAC starter is provided with a power cord connected to a switch /power receptacle block for mounting on the equipment.

See

Section

10.

Starting

regarding starter motor

service.

FIGURE

8-3.

TYPICAL FLYWHEEL ALTERNATOR

SYSTEM FOR BATTERY CHARGING AND

12

VDC

STARTER

FIGURE 8-4. TYPICAL FLYWHEEL ALTERNATOR

SYSTEM FOR CUSTOMER DC INTERFACE AND

110

VAC STARTER

a-3

Alternator

Output

Tests

Keep the following points in mind when testing or servicing the flywheel alternator.

CAUTION

Operatlon with reversed

positive

(+)

and negative

(-)

battery connections or without

connection to

a

battery

wlll

damage the voltage

regulator and/or the alternator stator.

1.

Never reverse the battery leads.

2.

Charging system tests require a fully charged battery in good condition. Make sure the engine is being run long enough and fast enough in service to recharge the battery after each start (engines with

12

VDC starters). Alternator output is proportional to engine speed and accessories consume power otherwise available for battery recharging.

3.

The voltage regulator has built in protection against open circuit and short circuit faults

)B+

terminal). It will not "turn on" under either condition or when battery discharge is extreme.

4.

Check to see that the connections at the terminals of the voltage regulator (three) or of the rectifier bridge (four) are clean and tight.

5.

Check to

see

that the wiring connected

to

the

B+

terminal (middle) of the voltage regulator or

to the

+

and terminals of the bridge rectifier

are not damaged, shorted or grounded.

6.

To ensure a, good ground path to battery negative

(-),

check to

see

that the voltage regulator

mounting surface is clean and that the screws

are tight.

6.

Check

to

see that the positive and negative battery cables have good connections at the battery and engine and that they are not damaged.

After checking all of the above perform the following tests

if

there

still

is no alternator output when the en-

gine is running between

1800

and

3600

RPM.

Refer

to Table

8-1

for test specifications.

Use

a multi-me-

ter (Simpson

270)

when testing the alternator.

1.

Check battery voltage when the engine is not running. (Not applicable on recoil or

11

0

VAC

starter engines.)

If

not within specifications

(Table

8-l),

charge the battery before going to

Step

2.

With the engine running, check voltage regulator output (DC voltage) at the battery terminals

or

bridge rectifier output (DC voltage), as appli-

cable. Replace the

voltage

regulator

if

output

is greater than specified.

If

voltage regulator

or

bridge' rectifier output is less than specified, go to Step

3.

Disconnect the alternator stator leads from the

voltage regulator

or

bridge rectifier and test

for

alternator stator output (AC voltage) with the engine running.

If

stator output is less than

specified, go to Step

4.

If

stator output is as specified but voltage regulator or bridge rectifier output is

low,

replace the voltage regulator or

bridge rectifier.

4.

Shut down the engine and check for electrical

resistance between either alternator stator lead and ground (bare engine metal) with an

ohmmeter. The meter should indicate infinite

resistance on its highest scale.

If

resistance is

high, go to Step

5.

If

not, replace the stator.

5.

Check alternator stator resistance by'connecting an ohmmeter across the stator leads. Replace the alternator stator assembly

If

stator re-

sistance on the lowest scale of the meter is either higher or lowerthan specified. Replace the flywheel assembly

if

alternator stator resis-

tance

is

as specified but alternator stator output

is

less than specified. The probable cause is

loss

of magnetism.

ALTERNATOR

Non-Battery

Charging

Alternator

5 Amp

Battery

Charging

Alternators

15Amp

Battery

Charging

Alternators

20 Amp

Battery

Charging

Alternators

A

Spec

2.5 Amp Battery

Charging

Alternator

BATTERY VOLTAGE

12 to 13

VDC

12 to 13

VDC

12 to 13

VDC

12 to 13

VDC

TABLE

8-1.

VOLTAGE

REGULATOR

OUTPUT

13.6 to 14.7 VDC at Any Speed in

Operating Range

13.6 to 14.7 VDC at Any Speed in

Operating Range

13.6 to 14.7 VDC

at

Any

Operating Range

ALTERNATOR OUTPUT TEST SPECIFICATIONS

BRIDGE

RECTIFIER

OUTPUT

Approx.

at 1800

Approx.

at

3600

30

RPM

60

RPM

VDC VDC

ALTERNATOR

STATOR

OUTPUT

Approx. 29 VAC

at 1800

RPM

Approx. 57 VAC

at 3600

Approx. 29

at 1800

RPM

VAC

RPM

Approx. 57 VAC

at

3600

RPM

Approx. 29

at 1800

VAG

RPM

Approx. 57 VAC

Speed

in

at 3600

Approx.

at

Approx. 57 VAC

at

1800

3600

RPM

29

RPM

VAC

ALTERNATOR

STATOR

RESISTANCE

0.27-0.33

Ohms

0.27-0.33 Ohms

0.54-0.66

0.30-0.36

Ohms

.

Section 9. Fuel

~AWARNING]

Incorrect service or replacement of

parts can result in severe personal injury and/or

equipment damage. Service personnel must be qualified to perform electrical and/or mechanlcal service.

/AWARNING

1 Accidental starting of the engine can result in severe personal injury or death. Disconnect the negative battery cable and spark plug wires while servicing engine, con-

trols, or associated equipment.

[AWARNING]

Ignition of fuel can result In severe

personal injury or death. Do not smoke or allow

any spark, pilot light, or arcing switch or eguipment near the fuel system or in areas with shared ventilation.

GASOLINE CARBURETOR

Disassembly --

not applicable, Sp& E

Carburetor parts are delicate and must be handled

k-l

with care. Never force parts when disassembling or assembling.

Remove the air cleaner assembly and disconnect

the fuel line and throttle and choke links. Remove the carburetor assembly from the intake manifold.

Refer to Figure 9-1 for Spec C and to Figure 9-2 for

Specs A and B. Remove the float bowl, slide the float pin out and remove the float and float valve.

Remove the main jet and idle adjusting screw and

spring. For Specs A and B also remove the main nozzle, passage cover and slow jet.

Inspection/Service -

not applicable

SPec E

Soak metal components in carburetor cleaner. Do not soak non-metal parts and gaskets. Follow the cleaner manufacturer’s recommendations and safety precautions.

Clean carbon from the carburetor bore, especially around the throttle and choke plates. Dry out all passages with low (35 psi) air pressure. Do not use

wire or other objects for cleaning passages as doing

so may damage the critical passages. Replace the float if it is cracked, damaged, or

loaded with fuel.

IDLE MIXTURE

LOW IDLE

MAIN

JET

FLOAT

BOWL

FIGURE 9-1. GASOLINE CARBURETOR (SPEC C)

9-I

CARBURETOR (BEGINNING SPEC

E)

Carburetor Replacement

Other than replacing the carburetor main fuel jet (fixed-type) with the optional high-altitude jet

(Fig-.

ure9-3a),fuelmixture adjustments should not be attempted. Nor should the carburetor be overhauled. Instead, a malfunctioning carburetor should be replaced. Before replacing a carburetor, however, make certain

1)

that all other necessary engine and generator adjustments and repairs have been performed and

2)

that the carburetor is actually

malfunctioning {see

Engine

Troubleshooting).

To

remove the carburetor, remove the air cleaner and air cleaner base, disconnect the fuel line and choke and throttle linkages and unbolt the carburetor from the intake manifold. When mounting the carburetor always use new gaskets. Readjust the choke and throttle cables and engine speed as instructed in the engine or equipment Operator’s Manual.

Carburetor High-Altitude Jet (Optional)

If

the engine

is

operated at an altitude above

5,000

feet

(1,524

metres),

it

is recommended that the car-

buretor main fuel

jet

be replaced with the optional

high-altitude

jet

(which has a slightly smaller ori-

fice).

CAUTION

To

avoid slipping

and

gouging the

maln

fuel

jet

use

a screwdriver wlth

,a

5/16

inch

(8

mm)

wide blade.

TAMPER-RESISTANT

THROTTLE

CHOKE

PLUG

OVER

IDLE

LEVER

MIXTURE

NEEDLE

STOP

SCREW

FIGURE

9-3a.

CARBURETOR

Replace the carburetor

if

there is excessive play

in

the choke and throttle shafts. Replace the idle adjustment needle

if

it

is bent, worn

or

damaged in

any

way.

Assembly

CAUTION

The mixture adjustment screw is easiiy damaged. Turn the mixture adjustment screw in only until light tension

can

be

feit.

When installing the idle adjusting screw, turn the screw in until LIGHT tension is felt. For Spec

C

turn

the screw

out

3-1/8 turns. For

Specs

A

and B turn

the screw

out

2-1/2

turn.

Turn the carburetor body upside down to assemble

the main jet, main nozzle (Specs

A

and

B),

float

valve, float and float bowl as illustrated in Figure 9-1

or

9-2.

Torque the carburetor mounting

bolts

to

the torque

specified in

ASSEMBLY

TORQUES,

reconnect the fuel line and throttle and choke links and secure the air cleaner assembly.

See the instructions that follow in this section

for

governor, choke and

speed

adjustments.

Co

Adjustment

If

a

CO

(Carbon Monoxide) meter is available, ad-

just the idle mixture screw to provide

6%

to

7%

CO

at

3300

rpm

with

no load on the engine.

If

a meter

is

not available, set the idle mixture screw at

3-1/8

turns

out

(Spec

C)

or

2 1/2

turns

out

(Specs A and

B)

as noted above.

LOW

IDLE

FLOAT

CHAMBER

FIGURE

9-2.

GASOLINE

CARBURETOR

(SPECS

A

AND

B

)

9-2

IMPULSE FUEL .PUMP

The engine may be equipped with an impulse type fuel pump that uses crankcase pressure (vacuum)

pulses to operate a spring loaded diaphragm inside the pump to pump the fuel through valves. Engine crankcase vacuum is connected through a hose to the back of the pump. The fuel flow direction is marked on the cover of the pump.

two

check

performance.

tube.

7.

If

the gasoline has been stored for an extended

time, drain and properly dispose of the old gas-

oline. Refill the fuel tank with fresh unleaded regular gasoline.

If

fuel delivery problems still occur, perform the fol-

lowing performance checks based on the symptom.

Also

check the seal

on

the oil

fill

Use

adequate ventilation when working on the fuel system. Prevent ignition sources in the areas sharing ventilation.

If

the fuel pump leaks, replace it. This fuel pump is

a

not intended to be rebuilt for

WARNING

ignition

of

fuel can result in severe

personal injury or death.

any spark, pilot light, or arcing switch

fuel leak problem.

Do not smoke

or

allow

equip-

ment near the fuel system or in areas with

shared ventilation.

Inspection/Service

If

a problem with fuel delivery to the engine is pected, check the following items before inspecting the fuel pump.

1.

Make sure the fuel shutoff valve is open.

2.

Check the fuel filter and replace

3.

Make sure the fuel hoses are not kinked or pinched, causing a fuel restriction. Dips and excessively long runs of fuel line in a hot area can cause vapor locking.

4.

Check the fuel tank cap for a restricted vent.

5.

Check the oil level to make sure

mark.

6.

Inspect the crankcase, especially at the gaskets, for visible oil leaks, indicating crankcase air leakage that can cause reduced fuel pump

it

if

it

is at the full

sus-

required.

Engine

mediately remove and inspect the spark plug.

If

the

check for:

If

the

ignition sparks can not ignite the gasoline.

Remove the fuel line from the carburetor and splice

in a

Place the end of the fuel line in the gasoline Crank the engine with the electric starter should be fuel flow into the container. fuel flow from the pump, replace the fuel pump instructed in this section.

Engine Runs But

If

the engine starves for fuel at high load, connect a

gravity feed fuel supply directly to the carburetor.

Plug the fuel line from the fuel pump during this test.

If

the gravity feed fuel supply eliminates fuel starva- tion, replace the fuel pump tion.

not the cause.

Will

Not

Start:

plug

is

wet and

An ungrounded ignition ground wire

A

defective throttle plate or low oil pressure switch or other equipment switch for ignition grounding

A fouled spark plug An improperly adjusted carburetor choke

plug Is

fuel

If

the fuel starvation continues, the fuel pump is

dry,

ground the spark plug lead

line of approximately eight inches in length.

or

the recoil starter for

Crank the engine, then im-

it

has a strong gasoline odor,

so

a

container to collect

20

seconds. There

If

there is no

Will

Not Operate At High Load:

as

instructed in this

that'

as

sec-

9-3

Fuel

Pump

Refer to Figure rebuilt and should be replaced as a complete as-

sembly. pump (it may

1.

Turn

2.

Place a drip pan under the fuel pump and car-

buretor to collect fuel.

3.

Disconnect the starting battery (if equipped). Disconnect the negative

duce the risk of arcing.

4.

Remove the air cleaner cover and air filter assembly.

5.

Loosen the screws that secure the fuel pump to

the air cleaner pan assembly.

6.

Disconnect the pulse hose from the fuel pump.

'Removal

9-3.

The pump is not intended to be

off

the fuel shutoff valve at the tank.

(-)

cable first to re-

7.

Disconnect the inlet -fuel hose from

pump.

8.

Disconnect the outlet fuel hose

cleaner the fuel pump).

9.

Remove the fuel pump.

Fuel

Pump

Install the new fuel pump in reverse order al. Replace any damaged or deteriorated fuel lines. After installation, check governor and engine speed adjustments for proper engine response.

Tighten all mounting hardware to that specified in

Assembly

pan

lnstallation

Torques.

the

fuel

from

the

fuel

be

necessary

mounting screws to gain access to

to

loosen

of

the

air

remov-

IMPULSE

9-4

FUEL

LPG

FUEL

SYSTEM

Refer to Figure

9-4.

The carburetor, gas pressure

regulator, air pump and vacuum sustain valve com-

prise the

LPG

fuel system components that are part

of the engine assembly.

A

vacuum cutout device is

provided by the equipment manufacturer. The carburetor should not require service and there

are no replaceable parts or adjustments except for the low idle speed screw.

WARNING

Carbon Monoxide

(CO)

Is deadly!

The Idle mixture screws

on

the carburetor and

gas pressure regulator are factory set and

sealed.

DO

NOT

READJUST.

Note: It is the responsibility

of

the user to make

cer-

tain that indoor carbon dioxide regulations

are

met.

Referring to the block diagram,. operation of the

LPG

fuel system is as follows:

1.

Crankcase vacuum

pulses

cause the air pump to pump clean air from the air cleaner to the vent side of the gas pressure regulator, which has a factory adjusted and sealed bleed valve. This provides for a precisely adjustable flow of gas for proper idle mixture.

2.

The vacuum sustain valve consists of a check valve and bleed-off

orifice.

It

bleeds off crankcase vacuum when the engine stops to cause the vacuum lock-out device to shut off the gas supply. The check valve removes the vacuum pulses permitting the

lock-out

device to open

during cranking.

The air pump

is

identical to the gasoline fuel pump

See

the instructions that follow in this section for

illustrated in Figure

9-3.

governor, choke and speed adjustments.

I

I I

I I I

PEED SCREW

I

LPG

SUPPLY

TANK

L----,,,

LPG CARBURETOR

I

CRANKCASE VACUUM

I

VACUUM

PULSES

Device

AIRPUMP

PRESSURIZED

AIR REGULATOR

PRESSURE

I

t

AIR

CLEANER

I

FIGURE

9-4.

LPG CARBURETOR AND FUEL

SYSTEM

BLOCK DIAGRAM

9-5

GOVERNOR

In order to obtain the best performance from the equipment it is essential that the governor lever, low and high idle speeds, choke and speed control cable be adjusted properly.

Symptoms of improper adjustment are: excessive

loss

of engine speed under load, engine stalling, no-load speed surging, poor starting and spark plug fouling.

The equipment Owner's Manual and high idle speed settings for optimum performance. Always set engine speed with an accurate tachometer. Never exceed the high speed setting specified by the equipment manufacturer.

The order of adjustments in this section followed in order to obtain proper adjustments. The order is as follows:

1.

Governor Lever Adjustment

2.

Idle Speed Adjustments

3.

Choke Adjustment

4.

Speed Control Cable Adjustment

1.

Governor Lever

Refer to Figure 9-5. The proper angular relationship between the governor lever and the governor shaft is essential for obtaining the speed/load performance. The position of the gover-

nor lever should be readjusted whenever the intake

manifold is reinstalled after removal for service.

Governor Lever Removal:

Spec C gasoline engines is secured to the tapered governor shaft with a nut. On LPG and Spec A and

ADJUSTMENTS

will

specify the low

Adjustment

full

range of engine

The governor lever on

MUST

be

Spec around the straight shanked governor shaft with a draw bolt and nut. Before removing the lever, stop the engine and disconnect the throttle link and governor spring. For Spec standard battery cable clamp lifter available at any automotive parts store to break the tapper fit between shaft and lever hub.

Governor Lever

stopped to assemble and adjust the lever.

B

gasoline

1.

Loosely assemble the governor lever and shaft

so

that the lever is free to rotate about the shaft.

2.

Attach the throttle link between the governor lever and carburetor. Replace the nylon clips they are

3.

Attach the governor spring, move the throttle control lever to align the lock pin holes in the control plate and throttle control lever and insert a pin 9-6.

4.

Check to see that the governor spring is holding the carburetor throttle plate in the wide open position.

5.

For Spec C gasoline engines tighten the lock nut on the end sure the 'governor shaft rotates clockwise against the internal governor parts, and torque to specifications. For LPG and Spec Spec screwdriver to rotate the governor shaft clock-

wise

tightening the lever draw

6. Remove the trol lever and proceed to the next adjustment.

B

against the internal governor parts while

engines the lever is clamped

C

gasoline engines use a

Adjustment: The

worn

or broken.

to

lock the lever in place.

of

the governor shaft making

gasoline engines

lock

pin to release the throttle con-

engine must be

use

a flat-bladed

bolt.

See

if

Figure

A

and

I-

CONTROL

LEVER

GOVERNOR

SPEC C GASOLINE

ENGINES

SHAFT

SPEC

FIGURE

LPG ENGINES

B

GASOLINE

9-5.

ENGINE GOVERNOR

ENGINES

9-7

LEVER

GOVERNOR SPRING

SPEC A

GASOLINE

ENGINES

2.

Idle

speed

Adjustments

WARNING

Too high

a

speed

settlng can cause

severe personal injury

or

death-

Follow the

manufacturer’s speclfications for

low

and high

idle speeds as found in the equlpment Owner’s

Manual. Use an accurate tachometer

High Idle

Speed

Adjustment;

Refer to Figure

9-6.

1.

Set up the tachometer according to the instruc-

2.

Start the engine according to the equipment manufacturer’s recommendations, observing all safety precautions, and allow the engine to warm up for at least

10

minutes.

3.

While the engine

is

running move the throttle

controi lever to align the

lock

pin holes in the control plate and throttle control lever and insert a pin to lock the lever in place. Loosen the speed control cable clamp

if

necessary.

4. Loosen the choke rod clamp screw and push the choke rod towards the carburetor

so

that

the choke will be fully open.

5.

High idle speed is adjusted by rotating the con-

trol plate around the pivot bolt-away from the

carburetor to increase speed and toward the carburetor to decrease speed. Therefore,

loos-

en the control plate pivot

bolt

1/8

turn and the

the control plate set

bolt

1/4

turn. Adjust high

idle

speed

to that specified by the equipment manufacturer, tighten the control plate bolts, recheck speed and readjust

if

necessary.

6.

Remove the lock pin to release the throttle con-

trol lever.

tions with the tachometer.

bow

Idle

Speed

Adjustment;

Refer to Figure

9-7.

1.

Continue running the engine with

the

tachome-

ter connected and move

the

throttle

control

le-

ver to the

low

idle speed position.

2.

Adjust engine speed

to

the specified low idle

speed by’

turning

the

low idle speed screw on

the carburetor. See Figure

9-1, 9-2

or 9-4, .as

appropriate. Shut

off

the engine and proceed to

the choke adjustment.

SPEED

CONTROL

CABLE

CLAMP

9/64

IN.

(3.5

mm

LOCK

HOLE

CONTROL

PLATE

PIVOT

PLATE

BOLT

FIGURE

9-6.

HIGH

IDLE SPEED ADJUSTMENT

-LOW

IDLE

SPEED

.POSITION

OF

ME

THROTTLE

CONTROL

LEVER

3.

Choke

Adjustment

Refer to Figure

9-8.

Proper choke adjustment is essential for obtaining consistent starting at low temperatures and wide open operation under normal running conditions.

1.

Shut

off

the engine and loosen the choke rod

clamp screw

so

that the rod is free to move

in

the choke swivel.

2.

Move the throttle control lever to align the lock pin holes in the control plate and throttle control

lever and insert a pin, making sure the pin ex-

tends past the choke lever to function as a stop

for

the choke lever.

3.

Push the choke rod towards the carburetor to

make sure the choke is fully open.

4.

Rotate the choke lever towards the carburetor

until the lever bears against the pin stop.

5.

Tighten the choke rod clamp screw. For Spec

A

gasoline engines there must be a

0.01

to

0.03

inch (0.25 to

0.76

mm) gap, as shown, between

the choke and throttle control levers.

6.

Remove the air filter paper element and check that the choke is fully open. Remove the lock pin in the control plate and check operation

of

the choke linkage.

If

the linkage binds, replace

the components that are damaged.

7.

Proceed to the following

speed

control cable

adjustment.

SPECS

BAND

C

9/64

IN.

(3.5

mm)

MAKE

SURE

THE

LOCK

PIN EXTENDS

LEVER

TO FUNCTION

AS

A

STOP

FOR

THE

LEVER

PAST

THE

CHOKE

SPEC

A

0.01

to

0.03

in.

(0.26

to

0.76

mm)

GAP

FIGURE

9-8.

CHOKE ADJUSTMENT

9-9

4.

Speed

Control Cable Adjustment

Refer to Figure

9-9.

The speed control cable must be installed properly to obtain full-load, full-speed operation. Adjust the speed control cable as fol-

lows:

1.

Stop the engine and loosen the speed control cable clamp located on the engine throttle control plate.

2.

Push the speed control lever on the equipment to the high speed position. On equipment without a separate choke control be sure the speed control lever is not in the start or choke position.'

3.

Move the throttle control lever to align the lock pin holes in the control plate and throttle control lever and insert a pin to lock the lever in place.

4.

Remove the slack

from

the speed control cable and tighten the speed control cable clamp. Remove the lock pin in the control plate.

5.

Start the engine according to the equipment

manufacturer's recommendations, observing

all safety precautions.

PULL CABLE

SHEATH

THIS

WAY

TO

REMOVE

CABLE

SLACK

SPEED CONTROL

9/64

IN

(3.5

mm)

CABLE CLAMP LOCK PIN

HOLES

ALTERNATE SPEED

\

CONTROL

CABLE

THROTTLE

CLAMP LOCATION CONTROL LEVER

TYPICAL EQUIPMENT

SPEED CONTROL

FIGURE

9-9.

SPEED

CONTROL

CABLE

ADJUSTMENT

AIR

CLEANER

Foam Wrapper Element

Refer to Figure

9-9.

See Periodic Service Schedule

for

foam wrapper service interval. Remove the outer air cleaner nut and plastic outer cover. When servicing the foam wrapper only

Do

NOT

remove

the inner air cleaner nut and inner cover. Wipe away loose dirt and chaff from the air cleaner

assembly and then remove the foam wrapper by pulling the foam wrapper over the inner cover. Wash the foam wrapper in water and detergent and

squeeze dry like a sponge. Rinse with water.

Dry

the

foam wrapper by compressing between several

sheets of paper toweling. Apply

2

tablespoons of

new engine oil and knead into the foam wrapper until it is evenly distributed. Remove excess oil by compressing the foam between several sheets of

paper toweling. Failure to remove excess oil

will

cause the paper air cleaner to become oil soaked.

This will cause a

loss

in engine performance and a

shortened paper air cleaner element life.

Install the foam wrapper over the paper air cleaner element by stretching over the inner cover.

Com-

pletely cover all exposed paper pleats on the air cleaner paper element.

If

the foam wrapper has

stretched

or

become tom, replace the foam wrap-

per. Assemble the outer air cleaner cover and nut.

Paper Element

Refer to Periodic Maintenance Schedule for air cleaner service and replacement interval. Service

or

replace more often when operating under severe

operating conditions.

Remove the outer air cleaner nut and plastic outer cover. Wipe away loose dirt and chaff from the air cleaner assembly and then remove the inner air cleaner nut and inner air cleaner cover. Remove the air filter paper element and foam wrapper from the engine. Wipe off excess dirt from air cleaner base and install the new paper element, inner cover and inner nut. lighten the inner nut one and a half turns after seating on the inner cover. Service the foam wrapper per the instructions given above. Assemble the outer air cleaner cover and nut.

LPG ENGINES

GASOLINE ENGINES SPECS

A AND

B)

GASOLINE ENGINES (SPEC C)

Section

10.

Starting

WARNING

Incorrect service or replacement of

parts

can result in severe personal injury and/or

equlpment damage. Service personal must

be

qualified to

perform

electrical and/or mechanl-

cal service

WARNING

Accidental starting of the englne can result In severe personal Injury or death. Disconnect the negative

(-)

battery cable and

spark

plug

wife before serviclng the englne,

controls, or associated equlpment.

RECOIL

STARTER

Disassembly:

Refer to Figure

10-1.

Remove the four capscrews holding the recoil assembly on the engine. Remove the recoil assembly from the blower housing.

Inspection/Service

Inspect the assembly as a

unit. The

rope

should pull out freely with spring ten-

sion, pulling the

rope

back in without binding or

slack. When pulling the rope

out,

the

dog

ears

should come out of their cup and they should not

be

bent, broken, or missing.

Assembly;

Place the recoil assembly on the blower housing. Install and torque the four capscrews to the torque specified in

Assembly

Torques.

CAP

SCREW

RECOIL

ASSEMBLY

M-1811

FIGURE

10-1.

RECOIL STARTER REMOVAL

110

VAC STARTER

Disassembly:

Refer to Figure

10-2.

Remove the

two

drive cap mounting screws and remove the as-

sembly from the engine.

Inspection/Servlce:

Replace the entire plug/

switch/motor assembly

if

the motor does not oper-

ate or is not strong enough to turn the engine. Re-

place the pinion gear and associated parts

if

the pinion is worn and/or binds on the shaft. The parts are available in kit form. Follow the kit instructions.

If

the

drive cap bearing appears worn, replace the drive

cap.

a

PLUG/

SWITCH/MOTOR

ASSEMBLY

DRIVE

CAP

FIGURE

10-2.110

VAC STARTER

10-1

SOLENOID

SHIFT

STARTER

WARNING

Accidental starting of the engine can result In severe personal Injury or death. Disconnect the negative

(-)

battery cable and spark plug wire before servicing the engine, controls, or associated equipment.

Inspection/Service:

With the starter assembled,

disconnect the connecting lead from the starter

so-

lenoid C terminal. Connect a jumper lead from the connecting lead to the battery positive terminal. Connect a jumper lead momentarily between the starter motor housing and the battery negative terminal. If the motor doesn't run, check the motor for problems.

Disassembly:

Refer to Figure

10-3.

Remove the starter from the engine. Unscrew the solenoid mounting nuts and disconnect the connecting lead. Remove the solenoid by sliding it up to disconnect the shift fork. Unscrew the

two

motor through bolts and remove the motor end bell. Carefully remove the brush insulator, brushes (four), brush springs and brush holder. Separate the motor frame from the drive housing and then draw the armature

out

with the shift fork.

Assembly:

Refer to Figure

10-3.

Assembly is the

reverse of disassembly. Apply grease to the shift fork hinge and prongs and the splines on the armature shaft.

Solenoid

Attraction

Text:

Connect a jumper lead from the

ST

terminal to the positive terminal

of

a 6 volt bat-

tery. Connect a jumper lead between the

C

terminal

and negative terminal of a

6

volt battery. If the

plunger pulls in and holds strongly, the solenoid is good;

if

it doesn't, replace solenoid.

Retention

Test:Connect a jumper lead from the

ST

terminal to the positive terminal of a 6 volt battery.

Connect a jumper lead between the solenoid body and negative terminal of a

6

volt battery. Push the

plunger

in and release it.

If

the plunger stays in, the

solenoid is good; if it doesn't, replace solenoid.

Plunger Return Stroke:

Apply

12

volts between terminal C and the solenoid body. Push the plunger in and then release it.

If

the plunger returns immedi-

ately, the solenoid is good; if

it

doesn't, replace sole-

noid.

V..

BRUSH

SPRING

Armature

Continuity Between Segments:

Refer to Figure

10-4.

Check for continuity between the segments of

the commutator.

If

there is no continuity, replace the

armature.

Armature Coil Core and Commutator Continu-

ity: Refer to Figure

10-6.

Check for no continuity

be-

tween the commutator and armature’s

shaft.

If

con-

tinuity exists, replace the armature.

commutator

ES1872

COMMUTATOR

FIGURE

106.

MEASURING ARMATURE SHAFT

AND COMMUTATOR CONTINUITY

flGURE

10-4.

MEASURING SEGMENT

CONTINUITY

Armature Coil Core and Commutator Continu-

ity:

Refer to Figure

10-5.

Check for no continuity be-

tween the commutator and the armature coil core.

If

continuity exists, replace the armature.

Armature Shaft and Bushing Clearance:

Refer to

Figure

10-3,

10-7,

and

10-8.

Measure the bushing

inside diameter in the starter drive housing and end frame. Measure the armature shaft outside diameter on the pinion side and commutator side.

If

the

clearance is not as specified in

Dimensions

and

Clearances,

replace the bushing.

COMMUTATOR

ES1873

FIGURE

10-5.

MEASURING ARMATURE COIL

CORE AND COMMUTATOR CONTINUITY

BUSHING

STARTER

DRIVE

HOUSING

ES-1876

FIGURE

10-7.

MEASURING STARTER DRIVE

HOUSING INSIDE

DIAMETER

10-3

PINION SIDE

ARMATURE

OF

SHAFT

ES-1877

SEGMENT MICA

EDGES UNDERCUT

DEPTH

SAW

BLADE

FIGURE

Commutator

Commutator:

10-8.

MEASURING ARMATURE

SHAFT OUTSIDE DIAMETER

And

Mica

Refer to Figure

10-9.

Clean commutator surface with sandpaper. Measure the commutator outside diameter at several points.

If

the differ-

ence of the outside diameter is not as specified in

Dimensionsand Clearances,

tor on a lathe to

factory

correct the commuta-

specifications.

If

the minimum outside diameter is less than the allowable limit, replace the armature.

ES-1879

FIGURE

Starter

Inspection:

10-10.

Body

Refer to Figure

MICA UNDERCUT DEPTH

10-11.

Check for continuity across the starter body and brushes. There are four brushes in the starter body. The not grounded are

180"

apart starting at the terminal

which connects to the solenoid. The

90"

grounded are located

terminals.

If

continuity exists at the non-grounded

terminals, replace the starter

from the non-grounded

body.

two

that are

two

that are

If

continuity

does not exist at the grounded terminals, replace

the starter

body.

NON-GROUNDED

TERMINAL

FIGURE

Mica:

Refer to Figure

dercut depth.

fied in

10-9.

MEASURING COMMUTATOR

OUTSIDE

If

the undercut

Dimensions

DIAMETER

10-10.

and

Clearances,

Measure the

is

less than that speci-

blade to increase the depth and then chamfer the segment edges.

ES-1878

mica

un-

use a saw

'

FIGURE 10-11. CHECKING

BODY CONTINUITY

FOR

ES-1880

STARTER

Brushes

Inspection/Service

Refer to Figure

10-12.

Clean the brush base with sandpaper. Measure the brush length.

mensions and Clearances,

If

the length is not as specified in

replace the starter body

Di-

and brush holder.

Es-1881

age.

Do

not clean overrunning clutch in liquid

cleaning solutions. Inspection/Service

the pinion and spline teeth for wear and damage.

Refer to Figure

10-13.

Inspect

If

wear or damage exists, replace pinion. Rotate the

if

pinion clockwise and see

if

the pinion

see

if

it doesn't. Rotate the pinion clockwise to

it

locks.

Replace the pinion

it turns freely. Replace

if

it doesn't.

PINION

FIGURE

10-12.

MEASURING BRUSH LENGTH

Overrunning Clutch

WARNING

Cleaning overrunning clutch In Iiq-

uid cleaning solution

wlll result in starter dam-

FIGURE

10-13.

CHECKING PINION

PROPER OPERATION

FOR

10-5

Section

11.

Engine

B

INTRODUCTiON

This section covers service procedures for the engine block assembly.

A

compression test can be

performed to determine the condition of the engine.

WARNING Accidental starting

of

the engine can result in severe personal injury or death. Disconnect the negatlve

(-)

battery cable and spark plug wire before servicing the engine, controls,

or

associated equipment.

ENGINE DlSASSEMBLY/ASSEMBLY

When complete engine disassembly is necessary, first remove all complete assemblies. Individual assemblies such as the carburetor can be disassembled and repaired at another time.

Suggested Disassembly Order

1.

Drain crankcase oil.

2.

Disconnect all fuel, exhaust and electric lines.

3.

Remove the engine from its mountings and place it on a suitable bench or work stand.

4.

Remove the muffler, chaff screen, blower housing, cylinder air housing, etc.

5.

Remove the air cleaner assembly, carburetor, and air deflector.

6.

Remove the ignition module.

7.

Remove the flywheel using a puller.

8.

Remove all accessories such as oil filter, starter, intake manifold, exhaust manifold, spark plug, etc.

9.

Remove the valve cover and cylinder head assembly.

IO.

Remove the oil base carefully, keeping all end play shims on their respective shafts.

1.1.

Remove the balance shaft assemblies.

1

2.

Remove the connecting rod and piston.

13.

Remove crankshaft and camshaft assemblies.

Keep all parts in their respective orders. Keep valve

assemblies together. Analyze the reasons for parts

failure.

lock

Assembly

Suggested Assembly Procedure

Engine assembly

is

normally the reverse

of

the disassembly procedure, observing proper clearances and torques. Use a torque wrench to assure proper tightness. Coat the internal engine parts with oil as they are assembled. After the internal engine parts are assembled, the engine should turn over by hand freely.

Use

only genuine Onan parts and special

tools when reassembling your engine.

1.

Install tappets, crankshaft and camshaft as-

2.

Install the connecting rod and piston.

3.

Install the balance shaft assemblies.

4.

Install the oil base, reuse the original end play

5.

Install the cylinder head assembly and lash

6.

Install the accessories such as valve cover,

oil

filter, starter, intake manifold, exhaust manifold, spark plug, etc.

semblies.

shims on their respective shafts.

valves.

7.

Install the flywheel and ignition module.

8.

Install the air deflector, carburetor, and cleaner

9.

Install the cylinder air housing, muffler, blower

assembly.

housing, chaff screen, etc.

I

10.

Install the engine on its mounting.

11.

Connect all fuel, exhaust and electric lines.

12.

Fill crankcase with oil.

Operation

Start the engine and check oil pressure. Run for ap- proximately

15

minutes to bring engine to operating

temperatures. Check for oil leaks, fuel leaks, and

exhaust leaks. Adjust carburetor and governor for speed, and sensitivity.

I

Compression Test Assembly

The compression tester is used to determine the

Clean tapered section of the flywheel

so

no oil or dirt

condition of valves, piston, piston rings and the

are present. Install woodruff key on the crankshaft.

engine cylinder.

Install flywheel on crankshaft and tighten to torque

specified in

Assembly Torques.

Install sheet metal.

To

check compression: Tighten bolts to torque specified in

Assembly

1.

Run the engine until thoroughly warm.

Torques.

2.

Stop the engine and remove the spark plug.

VALVE COVER

3.

Remove the air cleaner and place the throttle

4.

Insert the compression gauge in the spark plug

5.

Crank the engine and note the reading. pull off the valve cover.

and choke in the wide open position. Remove the valve cover to gain access to the cylin-

hole.

1.

Remove the valve cover mounting bolts and

Refer to

Specifications

for compression pressure.

2.

Clean the valve cover.

Be

careful not to dam-

There may

be

variations due to equipment, tem-

age the surface of the cover where the gasket

perature, atmospheric conditions and altitude.

mounts.

These pressures are for a warm engine at cranking

3.

Clean the cylinder head and cover thoroughly

speed (about

300

rpm). in the cover gasket mating area. Make sure the

der head, breather assembly and valve system.

breather assembly

is

correctly seated in the

FLYWHEEL

cylinder head cavity.

4.

Install a new valve cover gasket.

Disassembly

5.

Place the valve cover in position and install the

WARNING

Accidental starting of the englne

can result In severe personal Injury or death.

Disconnect the negatlve

(-)

battery cable and

spark plug wire before the servlcing engine,

controls, or associated equipment.

WARNING

Incorrect flywheel removal can

result In severe personal Injury.

Do

not remove the flywheel nut completely when using the flywheel puller.

Remove screen or recoil starter assembly and fly-

wheel cup

if

equipped with recoil starter. Remove

sheet metal surrounding flywheel. Loosen the fly-

wheel mounting nut. Use a flywheel puller to re-

move flywheel. Remove the woodruff key on the crankshaft.

Service/Inspection

\

Remove dirt, chaff, or other contaminants from screen and flywheel. Inspect screen and flywheel for damage. Replace screen

if

damaged in any way.

Replace flywheel

if

ring gear

or

flywheel is damaged

in any way.

mounting bolts. Torque

all

of the bolts in a star

pattern until they are tightened to the specified

torque.

ROCKER ARM

Disassembly

Refer to

Figure11-1.

Remove snap ring and pull out

rocker arm.

Inspection/Service

Rocker

Am

and Rocker Am Shaft Clearance:

Measure the rocker arm shaft outside diameter. Measure the rocker arm inside diameter and calculate the clearance.

If

clearance is not as specified in

Dimensions .and Clearances,

replace the rocker

arms.

If

clearance

still

exceeds that specified in

Di-

mensions and Clearances,

replace rocker arm

shaft assembly.

Assembly

Apply engine oil to the rocker arm shaft. Assemble components on rocker arm shaft.

ROCKER

SNAP

RING

VT-1050

FIGURE 11-1. ROCKER

ARM

ASSEMBLY

CYLINDER

HEAD

Disassembly

Torquing or removlng the cylinder

head when hot (above

100F

[37C]

wlll result

in head damage.

Allow

the head

to

cool

to

below

100F

(37C)

before torquing or removlng.

Refer to Figure

11-2.

The engine must

be

at room temperature before starting this procedure. Remove the valve cover capscrews and valve cover. Remove the spark plug. Remove the rocker arm assembly by unscrewing bolt holding the assembly

on.

Pull

out

the push rods. Remove the remaining cylinder head screws and remove the cylinder head. Remove the cylinder head gasket.

ROCKER

ARM

ASSEMBLY

RETAlNlNG

BOLT

NUMBERS INDICATE CYLINDER

HEAD

BOLT

TORQUE SEQUENCE

c-1120

FIGURE 11-2. CYLINDER

HEAD

BOLTS

Assembly

CAUTION

Over torquing

bolts

can cause en-

gine damage.

Do

not over torque nuts.

Refer to Figure

11-2.

Install a new cylinder head gasket. Position cylinder head on engine and position rocker arm, bolts, and washers in positions shown. Make sure push rods are properly installed in tappets and rocker arm. tighten cylinder head bolts

to

the torque specified in

Assembly

Torques

in

the order: bolt

1,

bolt

2,

bolt

3,

bolt

4,

bolt

5,

bolt

6.

Bolts 2 and 4 must be retorqued after all bolts are torqued. Adjust valve clearance. Remove the gasket from valve cover. Install the breather in the cylinder head. Install a new valve cover gasket and tighten valve cover capscrews in a two-step cross pattern to the torque specified in

Assembly

Torques.

VALVE SYSTEM

This engine uses an overhead valve design, shown in figure

11-3.

A

properly functioning valve system is

essential for good engine performance. Use the fol-

lowing procedures to inspect and service the valve

system.

Tappets

Very little wear takes place on tappet diameters

or

in

tappet bores.

If

the clearance between tappet and

bore in the cylinder block exceeds specifications,

replace the tappet. Inspect the tappet faces which contact camshaft

lobes

for

roughness, scuffing,

or

concave wear. Replace any worn tappets. If tappets are worn, inspect the camshaft

for

wear.

Valves, Springs, Guides

Disassembly

Refer to Figure

11-3.

Compress valve springs and pull out the valve locks. Remove the valve spring retainer, valve spring, washer and valve.

VALVE

LOCKS

VALVE SPRING INTAKE SEAL STOPPER

CYLINDER

HEAD INTAKE VALVE

VALVE SPRING RETAINER WASHER VALVE GUIDE VALVE SEAT EXHAUST VALVE

11-4

Valve Stem and Valve Guide Clearance:

Refer to Figures

11-4

and

11-5.

Remove carbon from valve guide and valve stem. Measure the valve stem outside diameter at

six

positions. Measure the valve guide inside diameter at three positions. Calculate the clearance.

If

the clearance is not

as

specified in

Dimensions

and

Clearances,

replace

the valve.

If

clearance still exceeds the allowable

limit, replace the valve guide.

FIGURE

114.

MEASURING VALVE STEM

VALVE

GUIDE

FIGURE

11-5.

MEASURING

VALVE

GUIDE

Valve Guide Replacement:

CAUTION

Driving out old valve guides can

cause guide and guide

bore

damage.

Do

not

strike guide or guide

bores

wlth driver during

removal.

Refer to Figure

11-6.

Press

out

the used valve guide using a special valve guide replacing tool. Apply engine oil to a new valve guide. Install a

stopper

ring

to the valve guide. Press the new valve guide in until

the stopper ring contacts the cylinder head. Ream the new guide to achieve the specified stem to guide clearance.

STOPPER

RING

11-5

Assembly

Clean

off

any carbon on the valve stem and valve guide hole. Apply engine oil to the valve and valve guide. Assemble in reverse of disassembly procedures.

Valve

Spring:

Check valve springs for cracks, worn ends, distor-

tion, and tension.

If

spring ends are worn, check

valve spring retainer for wear. Check for spring dis-

tortion by placing the spring on a flat surface next to

a square. Measure height of spring (A) and rotate it against square edge to measure distortion (B), see Figure

11-7.

If

distortion exceeds

0.06

inch

(1.5

mm) replace the spring. Check spring tension at the valve open position using an accurate valve spring tester. Replace any valve spring that

is

weak,

cracked, worn, or distorted.

FIGURE

11-7.

MEASURING VALVE

SPRING

Valve

Face

and

Seat

Grinding

Before installing new or used valves, inspect the valve seats for proper valve seating.

If

used valves

are

reinstalled, the valve stems should be cleaned

and valve faces ground to their specified angles of

45F

Refinish valve

seats

to a

45"

angle. When refacing valves and seats, remove all evidence of pitting and grooving.

If

the end

of

the valve stem

is

pitted or

worn,

true

it

and clean

it

up on the refacer

11-6

wheel. A very light grind is usually enough to square the stem and remove any pits or burrs. The valve guide should be thoroughly cleaned.

If

the valve guide is worn, or the valve is warped, the necessary parts must be replaced.

Refinish valve faces to

a

45"

angle on a valve refac-

ing machine. The first cut from valve face must be a

light grinding. Check

if

there is an unevenness of

metal being removed.

If

only part

of

valve's face has

been touched, check to see

if

the valve is properly

seated in the machine or

if

the valve is warped, worn, or distorted. When cut is even around the whole valve face, keep grinding until the complete face is ground clean. Be sure the correct valve face angle is maintained. When the valve head is warped, a knife edge will

be

ground (Figure

11-8)

on part or all of the head due to the large amount of metal that must be removed to completely reface

the valve. 'Heavy valve heads are required for

strength and

good

heat dissipation. Knife edges lead to breakage, burning, and pre-ignition due to heat localizing on the edge.

Replace any valve that cannot be entirely refaced

while keeping a good valve margin (Figure

11-8)

or is warped, worn, or damaged in any way. The amount of grinding necessary to true a valve indicates whether the valve head is worn or warped.

WARPED

VALVE

WITH

KNIFE

EDGE

KNIFE

EDGE

GOOD

MARGIN

FIGURE

11-8.

VALVE

HEAD

MARGIN

Inspection/Service

Valve

Clean the valve seat width. Apply red lead to the valve surface to check for scratches and unevenness. urement is within that specified in

Clearances,

less than specified in

the cylinder head and valve and refit the valve seat.

Valve Seat Cuffing:

Seat

70%,

Width:

seat

surface. Measure the valve

check the seating ratio.

refit

it.

If

the measurement is not as

Dimensions

and

Clearances,

If

the meas-

Dimensions and

If

the ratio is

replace

valve and seat. Repeat the last correct, contact

is

achieved. seated rate becomes more than contact area.

I

two

steps until

Lap

valve until the

70%

of

the total

the

Refer to Figures seat up by using a valve and visually check the contact position

11-9

and

11-10.

45O

valve seat cutter. Replace the

Clean the valve

be-

tween the valve face and seat with red lead. Cut the

upper surface cutter until the valve seat touches to the center the valve face

11-10).

Cut the valve seat again with the

of

the valve seat with a

(A

should equal Bas shown in Figure

15"

valve seat

45"

of

valve

seat cutter and recheck the contact between the

15"

FIGURE

11-9.

VALVE SEAT CUTTER

45"

FIGURE

11-10.

VT-1049

VALVE SEAT CONTACT

11-7

Valve

Clearance:

The

engine must be at room temperature when per-

forming

the is

this test. Remove the valve cover. Remove

spark

plug. Turn the engine over until the piston

at

COMPRESSION

TOP

DEAD

CENTER. Check

the intake and exhaust valveclearance with a feeler

gauge.

sions

and

If

the clearance is not as specified in

and

Clearances,

turn

the lash adjusting screw until the correct di-

loosen the lash adjusting nut

Dimen-

mension is obtained. Tighten lash adjusting nut and

recheck

clearance measurement.

Shim as necessary to obtain the clearances specified in

Dimensions and Clearances.

Apply grease to the oil seal lip and make sure it's not damaged when installing the oil base. Be sure the oil pump shaft lines up with the slot on the balancer shaft. Tighten the oil base mounting bolts in a clockwise pattern to the torque specified in

Torques.

Torque the bolt first torqued once more.

Assembly

Y

VT-1058

FIGURE 11-11.

MEASURING

OIL

BASE

VALVE

LASH

:Disassembly

Remove the oil pressure switch located next to the .oil filter. Unscrew the oil base mounting screws. Tap .the oil base with a plastic hammer. Remove

base.

Do

not

pry

cover

off

with a screw driver chisel,

etc. Note where

ail

shims come

off

from.

oil

Assembly

Install a new original locations (Figure camshaft

oil

base gasket. Install shims in their

11-12).

or

balancer shafts have been replaced,

If

the crankshaft,

use Plasti-gage to check their end clearances.

GOVERNOR

With the oil base removed, the governor can

spected

or

disassembled for service. The governor

assembly must spin freely on the center pin without

or

excessive looseness

wobble. Sleeve tip wear is

the most common cause of governor failure. Check

for flat spots on the sleeve tip. sleeve, gear, or flyweights are worn

If

the governor

or

damaged, re-

place them. To disassemble, pull the governor gear assembly

off

the mounting shaft (Figure

11-13).

To assemble, install the washer, gear assembly, and retainer onto the shaft. Thread the sleeve between the flyweights and push the assembly onto the shaft. See inset drawing (Figure

11-13)

for position

of

flyweight and

sleeve.

11-8

be

in-

BALANCER

SHAFT

2

BALANCER

*-I

CT-1110

CT-1089-1a

FIGURE 11-13. GOVERNOR

RETAINER

BALANCING SHAFTS

Disassembly

Carefully pull each shaft out, one at a time.

Oil

Base Bearlng

Measure the balancer journal bearing

to

Shaft Clearance:

O.D.

on both

balancer shafts. Measure the corresponding base bearing specified in

I.D.’s.

If

the measurements are not as

Dimensions and Clearances,

replace

the defective parts.

Assembly

Refer to Figure the gears. The crankshaft has which must line up with balancer shaft shaft

1

has one alignment mark which must line up

11-14.

Align the alignment marks on

two

alignment marks

1.

Balancer

with the one alignment mark on balancer shaft

Install each shaft one at a time.

oil

2.

FIGURE 11-14. BALANCING

SHAFT

ALIGNMENT

CRANKSHAFT AND CAMSHAFT

Disassembly

Set the engine block

on

the flywheel side. Pull the crankshaft out with the camshaft. Remove the tappets.

Inspection/Service

Crankshaft Journal:

Refer to Figure nal.

If

the crankshaft journal is not as specified in

Dimensions and Clearances,

connecting rod and correct the crankshaft journal. Precisely grind the comer radius of the journal to a

0.07

to

0.09

the oil hole circumference with an oil stone to a to

0.06

inch

surface must be fine finished to higher than

(0.4

µm

Ra

11-15.

inch radius

(1-0

to

).

Measure the crankshaft jour-

use an undersize

(1.8

to

2.2

mm). Chamfer

0.04

1.5

mm) radius. The journal

6

11-9

Oil

Base

Bearing

to

Camshaft

Clearance:

OIL

FIGURE

Camshaft

Refer to Figure cam at its highest specified

11-15.

Lobe

Height:

11-16.

point.

in

Dimensions

the camshaft.

CRANKSHAFT

JOURNAL

RADIUS

CT-I111

CRANKSHAFT JOURNAL

Measure the height of each

If

measurements are not as

and Clearances,

replace

Measure the camshaft journal bearing sure the corresponding oil base bearing measurements are not

and

Clearances,

replace the defective parts.

as

specified in

O.D.

Mea-

I.D.

If

the

Dimensions

Assembly

Install tappets into the block. Refer to Figure Apply engine oil to the governor lever shaft. Apply grease to the

oil

seal lip and

be

careful not to roll the seal when inserting the crankshaft. Line the crankshaft and camshaft timing marks up and insert both

into the block at the same time.

11-17.

FIGURE

11-16.

MEASURING CAMSHAFT

HEIGHT

CT-1112a1112

LOBE

11-10

FIGURE

11-17.

CRANKSHAFT

TIMING

MARKS

AND

CAMSHAFT

COMPRESSION

RELEASE SYSTEM

This engine has a compression release system that, decreases the amount of effort required to start the engine and reduces engine run-on when stopping (Figure

11-18).

The system works as follows:

1.

As

the engine is started, a spring holds in the flyweight, which in turn pushes a decompression pin upward.

2.

The decompression pin pushes up on the exhaust tappet and opens the exhaust valve

momentarily to release compression and make starting easier.

3.

As

the engine

speeds

up, the flyweight is forced outward by centrifugal force and the decompression pin moves down

so

that

it

no

longer opens the exhaust valve.

4.

When the engine is stopped, engine speed drops and the flyweight pulls in and the decompression pin moves up. The pin opens the exhaust valve again releasing compression.

CAM

GEAR

I

ENGINE

TAPPET

START

POSITION

FLYWEIGHT

The most common problem with this system faulty spring. The spring may be too long

A

not be connected. duce the decompression cutoff the spring is properly attached,

spring that is too long will re-

speed.

if

a

problem with the

or

Make sure

cutoff speed is suspected, replace the spring.

it

is

may

a

FIGURE

11-18.

COMPRESSION

RELEASE

CT-1121.

SYSTEM

11-11

PISTON,

PISTON

PIN,

RiNGS,

CONNECTING ROD

Disassembly

CAUTION

Improper piston removal can cause

piston damage.

Use a rldge reamer

to

remove

cylinder ridge before removing plston.

Refer to Figure

11-19.

Unscrew the connecting rod screws and remove the connecting rod cap. Turn the crankshaft

so

the piston is at top dead center.

Pull the piston and connecting rod out of the cylinder liner. Make a mark on the piston on the same side as the machined surface on the connecting

rod.

CT-1097a-1097

FIGURE

11-19.

PISTON MARKING

Refer to Figure

11-20.

Remove rings from piston by using a ring tool. Remove the piston pin snap ring and push out the piston pin.

11-12

PISTON PIN

SNAP RING

FIGURE

11-20,

PISTON

ASSEMBLY

Piston Inspection

CAUTION

Improper

piston

cleaning can cause

piston damage.

Do

not use a caustic cleaning

solvent

or

wire

brush

for cleaning pistons.

Follow the procedures given below when inspecting pistons and connecting rods.

Piston Inspection:

1.

Inspect the piston forfractures at the ring lands, skirts and pin bosses. Check for wear at the ring lands using a new ring and feeler gauge (Figure

11-23).

Replace the piston when the side clearance of the top compression ring reaches that specified in

Dimensions and

Clearances.

2.

Replace a piston showing signs of scuffing, scoring, worn ring lands, fractures or damage from preignition. Excessive piston wear near

the edge

of

the top ring land indicates preigni-

tion.

Piston Pin Hole inside Dlameter:

Piston' Ring and Ring Groove Clearance:

Refer to Figure 11-21. Measure the piston pin hole inside diameter at various places. ment

is

not as specified in

ances,

replace the piston.

FIGURE 11-21. MEASURING PISTON PIN HOLE

Dimensions and Clear-

If

the measure-

.1100

Piston Pin Outside Diameter:

Refer to Figure

11-23.

Remove carbon from the ring grooves. Insert a new piston ring into the ring groove and measure the clearance at several

If

points.

Dimensions

the measurements are not as specified in

and Clearances,

FIGURE 11-23. MEASURING RING GROOVE

CLEARANCE

replace the piston.

Refer to Figure 11-22. Measure the piston pin outside diameter. fied in

Dimensions and Clearances,

If

the measurement

is

not

replace the

as

speci-

piston pin.

CT-1101

FIGURE 11-22. MEASURING PISTON PIN

Connecting

Refer

to

Rod

Small

End Inside Diameter:

Figure 11-24. Measure the connecting rod small end inside diameter with an inside micrometer.

If

dimension is not as specified in

and Clearances,

FIGURE 11-24. MEASURING CONNECTING

replace the connecting rod.

SMALL END

Dimensions

ROD

11-13

Connecting Rod

to

Crankshaft Journal Oil

Clearance:

Refer to Figure

11-25.

Measure the crankshaft jour-

nal outside diameter with an outside micrometer.

the dimension is not as specified in

Clearances,

grind the crankshaft journal and re-

Dimensionsand

place the connecting rod. Tighten the connecting rod screws to the torque specified in

Torques.

Measure the connecting rod large end inside diameter at the points shown. is not as specified in replace the connecting

If

the oil clearance is not as specified in

and Clearances,

Dimensions and Clearances,

rod.

Calculate oil clearance.

grind the crankshaft journal and

Assembly

If

the dimension

Dimensions

replace the connecting rod.

Assembly

Refer to Figure

oil

for

10

to

into the piston and connecting rod. Be sure the con-

If

necting

rod

as the piston mark.

77-26.

15

minutes and then insert the piston pin

Immerse the piston in

212°F

machined surface is on the same side

CT-1097

CT-1106

FIGURE

11-25.

MEASURING CONNECTING

LARGE

END

ROD

Connectlng Rod Side Clearance:

Assemble the connecting

rod

to the crankshaft. Measure the side clearance of the connecting on the crankshaft.

Dimensions and Clearances,

If

dimension is not as specified in

replace the connect-

ing rod.

rod

flGURE

Refer to Figure

11-26.

ASSEMBLING PISTON

11-27.

Always install new rings when assembling the engine. Existing rings will not seat properly. Install the rings with the ring manufacturer’s mark facing toward the top of the piston.

RING

MANUFACTURER’S

MARK

FIGURE

11-27.

RING

MARK

11-14

Refer to Figure

11-28.

Insert piston pin snap ring.

Position rings on piston as shown.

Gap

on top ring

must face opposite of intake and exhaust valves.

SECOND

TOP

RING

CT-1107cr-I107

FIGURE

11-28.

ASSEMBLING RINGS

Refer to Figure

11-29.

Apply engine oil to the cylin-

der liner. Line up the piston and connecting rod

so

the machined surface of the connecting rod faces towards the camshaft.

MACHINED

SURFACE

MUST

FACE

CAMSHAFT

CT1113

FIGURE

11-29.

PISTON ORIENTATION

CAUTION

An improperly installed piston wiil

cause engine damage. The machined side

of

the

connecting rod must face the camshaft.

Refer to Figure

11-30.

Use

a

ring compressor to in-

sert

the piston and connecting

rod

in into the cylin-

der liner. Apply engine oil to the inside diameter of

the connecting rod cap and connecting

rod

screws. Align the machined surfaces of the connecting rod and connecting rod cap. Apply oil

to

the connecting

rod bolts and tighten them

to

the torque specified in

Assembly

Torques.

MACHINED

SURFACE

MUST

FACE

CAMSHAFT

CT-1109

FIGURE

11-30.

CONNECTING

ROD

AND CAP

ALIGNMENT

CYLINDER

BLOCK

The cylinder block is the main support for all other

basic engine parts. The crankshaft and camshaft are supported by the block, assuring alignment of

the crankshaft and cylinder bore.

11-15

Cleaning

After removing pistons, crankshaft, cylinder heads, etc., inspect the block for cracks and wear.

If

block is

still sewiceable, prepare

it

for cleaning as follows:

1.

Scrape all old gasket material from block.

Remove oil by-pass to allow cleaning solution

to contact inside of oil passages.

2.

Remove grease and scale from the cylinder block by agitating

it

in a bath of commercial

cleaning solution

or

hot soapy washing

solution.

3.

Rinse the block in clean hot water to remove

the cleaning solution.

.Inspection

When rebuilding the engine, thoroughly inspect the block for any condition that would make

it

unfit for further use. This inspection must be made after all parts have been removed and the block has been

thoroughly cleaned and dried.

1.

Make a thorough check for cracks. Minute

cracks may be detected by coating the

sus-

pected area with a mixture of

25

percent kero-

sene 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

be-

come 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 the top of the block for flatness with a straight edge and a feeler gauge.

Cylinder

Bore

Inspection

Inspect cylinder bore

for scuffing, scratches, wear, and scoring.

If

cylinder

bore is scuffed, scratched, worn

,

or scored, it must

be rebored and honed for the next oversize piston. When the appearance of the cylinder bore

is

good and there are no scuff marks, check cylinder bore for wear or

out

of roundness as follows:

1.

Check cylinder bore for taper, out of round, and

wear with a cylinder bore gauge, telescopic

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 (Figure 11-31).

2.

Record

measurements taken at top and bot-

tom of piston travel as follows:

A. Measure and record as "A" the cylinder

.bore diameter (parallel to crankshaft) near

the

top of cylinder bore.

TOP

OF

CYLINDER

RING

WEAR

AREA

iBOTTOM

OF

RING

TRAVEL

B-418

FIGURE

11-31.

METHODS OF MEASURING THE

DIAMETER OF

A

CYLINDER BORE

B.

Measure and record as

"B"

cylinder bore

diameter (parallel to crankshaft) at the bot-

tom of piston travel.

C. Measure and record as

"C"

cylinder bore diameter (perpendicular to crankshaft) near the top of cylinder bore.

D.

Measure and record as

"D"

cylinder bore diameter (perpendicular to crankshaft) at the bottom of piston travel.

E.

Reading "A" subtracted from reading

"B"

and reading

"C"

subtracted from reading

"D"

indicates cylinder taper.

If

cylinder taper exceeds that specified in

Dimensions

and

Clearances

rebore and

hone cylinder to the next oversize.

F.

Reading

"A"

compared to reading

"C"

and

reading

"B"

compared to reading

"D"

indi-

cate whether or not cylinder

is

out of round.

If

out

of round exceeds that specified in

Di-

mensions

and

Clearances

the cylinders

must

be

rebored and honed to the next

oversize.

Reboring the Cylinder

Rebore and hone the engine whenever cylinder

bore is worn, damaged, out of round,

A

taper exceeds specifications. should be resized to the smallest standard oversize diameter at which it will clean up. The final finish and bore diameter should then

Final bore diameter should equal the standard di-

ameter added to the oversize.

CAUTION

damage.

improper boring will result in

Boring

must

worn cylinder bore

be

obtained by honing.

be

done by

or

if

cylinder

qualified

engine

mechanics.

After boring to the correct oversize cylinder bore di-

mension, piston and ring clearance should be appropriate. There is no need to adjust to "fit" piston and rings.

When reboring cylinder, take the following precautions:

1.

Make sure the cutting tool is properly ground before using

2. Be sure the top of engine block is smooth and deposit free.

3. Clean the base of the boring bar before bar is

set up. Deposits under the boring bar will cause it to tilt and the cylinder boring.

4.

Make an initial rough cut, followed by a finish cut. Then hone the cylinder bore to the specified oversize.

it.

will

be

distorted after

Honing Cylinder (Using Precision Hones)

Refer to hone manufacturer's recommended grit

size to produce specified surface finish of

40

RMS. Too rough

and too smooth of a finish can retard piston ring seating.

of

a finish will wear out the rings

20

to

1.

Position block solidly for either vertical or horizontal honing. Use either a drill press duty drill which operates at approximately to

450

rpm.

2.

Follow hone manufacturer's instructions for the

use

of oil or lubricant on stones.

bricants 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

chatter in cylinder bore, but will drag freely up

and down when hone is not .running.

4.

Connect the drill to the hone and

out

the bore for high spots, which cause an increased drag on stones. Move hone up and down in bore with short overlapping strokes about

40

times per minute. Usually the bottom

of'

cylinder is smaller. As the cylinder takes a uniform diameter, move the hone up and down all the way through cylinder bore.

5.

Check the diameter of the cylinder regularly during honing.

method but a telescoping gauge can 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 an included angle achieved by moving the rotating hone

450

rpm) up and down in cylinder bore about

40 times

7.

Clean cylinder bore thoroughly with soap, water and clean rags.

not become soiled on wall after cleaning is

complete.

since they wash oil from the walls but leave the

metal particles.

8.

Dry

crankcase and coat it with oil.

must be worked out first because

A

dial bore gauge is the easiest

of

23 degrees. This can be

per

minute.

A

clean white rag should

Do

not use a solvent or gasoline

or

Do

not use lu-

start

drill. Feel

be

heavy-

250

or

used.

form

(250

to

it

11-17

Deglazing

Cylinder

Bore

Deglaze the cylinder bore

if

there are 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,

so

the 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 bore with a clean cloth that 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.

Use a slow

speed

drill to drive the deglazing

tool. Move the deglazing tool up and down in

the cylinder

(10

to

12

complete strokes) rapidly

enough to obtain a crosshatch pattern

(Figure

11-32).

Improper cylinder cleaning

wlll

result In englne damage.

Do

not use gaso-

line, solvents, or commercial cleaners to clean cylinder

bore.

4.

Clean cylinder bore thoroughly with soap,

water and clean rags. Continue cleaning until

a

clean white rag shows no discoloring when

wiped through

the

cylinder bore.

PRODUCE

CROSS

AVOID

THIS

FINISH

HATCH SCRATCHES FOR

FAST

RING SEATING

C-1091s

FIGURE

11-32.

CROSSHATCHING

11-18

BALL

BEARINGS

I

The oil base holds one crankshaft bearing. The engine block contains one camshaft bearing, one crankshaft bearing and

two

balancer shaft bearings. Use a bearing puller to remove these bearings. Clean the bearing mounting surfaces and press new bearings back in.

OIL

SEAL

Use an oil seal remover

to

pry the

oil

seal out of the

engine block. Clean the oil seal resting surface and

lubricate the surface before installing a new oil seal.

Press the new oil seal into the engine block until the oil seal is flush with the cylinder block boss. Lubricate the lips

of

the oil

seal

with a light coating of

grease. This provides initial lubrication until engine

oil

reaches the seal.