Toro 73545, 73546, 73547, 73580 Service Manual

Page 1

KAWASAKI FD620D 4-STROKE LIQUID COOLED ENGINE SERVICE MANUAL

Table of Contents – Page 1 of 2

GENERAL INFORMATION

BEFORE SERVICING MODEL IDENTIFICATION GENERAL SPECIFICATIONS PERIODIC MAINTENANCE CHART EXCEPT U.S. PERIODIC MAINTENANCE CHART FOR U.S. TORQUE AND LOCKING AGENT

FUEL SYSTEM

EXPLODED VIEW SPECIFICATIONS GOVERNOR LINK MECHANISM CARBURETOR INTAKE MANIFOLD FUEL PUMP AIR CLEANER

COOLING SYSTEM

EXPLODED VIEW SPECIFICATIONS COOLING SYSTEM COOLANT DISASSEMBLY AND ASSEMBLY PRECAUTIONS WATER PUMP RADIATOR COOLING FAN, FAN BELT THERMOSTAT THERMO SWITCH

ENGINE TOP END

EXPLODED VIEW SPECIFICATIONS SPECIAL TOOLS CYLINDER HEAD VALVES CYLINDER, PISTON MUFFLER

LUBRICATION SYSTEM

EXPLODED VIEW ENGINE OIL FLOW CHART SPECIFICATIONS ENGINE OIL AND OIL FILTER PRESSURIZED LUBRICATION SYSTEM OIL PUMP AND RELIEF VALVE OIL SCREEN FILTER

Page 2

KAWASAKI FD620D 4-STROKE LIQUID COOLED ENGINE SERVICE MANUAL

Table of Contents – Page 2 of 2

CAMSHAFT / CRANKSHAFT

EXPLODED VIEW SPECIFICATIONS CRANKCASE BREATHER CAMSHAFT TAPPET CRANKSHAFT, CONNECTING ROD

ELECTRICAL SYSTEM

EXPLODED VIEW SPECIFICATIONS SPECIAL TOOLS WIRING DIAGRAM WIRE HARNESS PRECAUTIONS CHARGING SYSTEM IGNITION SYSTEM ELECTRIC STARTER SYSTEM

TROUBLESHOOTING

ENGINE TROUBLESHOOTING GUIDE STARTER MOTOR TROUBLESHOOTING GUIDE

Page 3

4-stroke liquid-cooled v-twin gasoline engine

Service Manual

Page 4

O-l

Kawasaki

FD62QD

4-stroke liquid cooled v-twin gasoline engine

Service Manual

All rights reserved. No parts of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic mechanical photocopying, recording or otherwise, without the prior written permission of Quality Assurance Department/Consumer Products Group/Kawasaki Heavy Industries,

Ltd., Japan. .’

No liability can be accepted for any inaccuracies or omissions in this publication, although every possible care

has been taken to make it as complete and accurate as possible.

The right is reserved to make changes at any time without prior notice and without incurring an obligation to

make such changes to products manufactured previously.

All information contained in this publication is based on the latest product information available at the time of publication. Illustrations and photographs in this publication are intended for reference use only and may not depict actual model component parts.

0 Kawasaki Heavy Industries. Ltd. 1996

Second Edition(l) : Jan. 20,1996(T)

Page 5

o-2

This warning may apply to any of the following components or any assembly containing one or

more of these components:-

Brake Shoes or Pads Clutch Friction Material Gaskets

Insulators

Emthing rbmto~

dust is dm~rous

instructionr

A ampere(s)

ABDC

ATDC

BBDC

BDC

BTDC

‘C

DCF

after bottom dead center alternating current

after top

dead center before bottom dead center bottom dead center before top dead center

degree(s) Celsius

direct current farad(s)

‘F degree(s) Fahrenheit ,

ft 9 gram(s)

foot, feet

hour(s) liter(s)

SAFETY INSTRUCTIONS

Operate if possible out of doors or in a well

ventilated place.

Preferably use hand tools or low speed tools equipped, if necessary, with an appropriate dust extraction facility. If high speed tools are used, they should always be so equipped.

lf possible, dampen before cutting or drilling.

@Dampen dust and place it in properly closed

receptacle and dispose of it safely.

LIST OF ABBRE(/IATIONS

lb m min

N Pa PS psi

rpm

TDC TIR

pound(s) meter(s) minute(s) newton(s) Pascal(s)

horsepower

pound(s) per square inch

revolution

revolution(s) per minute

top dead center

total indicator reading volt(s)

watt(s)

ohm(s)

Read OWNER’S MANUAL before operating.

Page 6

Foreword

o-3

This manual is designed primarily for use by

trained mechanics in a properly equipped shop.

However, it contains enough detail and basic

information to make it useful to the owner who

desires to perform his own basic maintenance and

repair,work. A basic knowledge of mechanics, the proper use of toofs, and workshop procedures must be understood in order to carry out maintenance and

‘repair satisfactorily.

insufficient experience or has doubts as to his ability

to do the work, all adjustments, maintenance, and

repair should be carried out only by qualified mechanics.

In order to perform the work efficiently and to

avoid costly mistakes, read the text, thoroughly familiarize yourself with the procedures before starting work, and then do the work carefully in a clean area. Whenever special tools or equipment are specified, do not use makeshift tools or equipment.

Precision measurements can only be made if the

proper instruments are used, and the use of substitute tools may adversely affect safe operation.

To get the longest life out of your engine:

Follow the Periodic Maintenance Chart in the

Service Manual.

Be alert for problems and non-scheduled mainte-

nance.

Use proper tools and genuine Kawasaki engine parts. Genuine parts provided as spare parts are

listed in the Parts Catalog.

FOIIOW the procedures in this manual carefully. Don’t take shortcuts.

*Remember to keep complete records of mainte-

nance and repair with dates and any new parts

installed.

Whenever the owner has

How to Use this Manual

In preparing this manual, we divided the product into its major systems. These systems became the manual’s chapters. All information for a particular

system from adjustment through disassembly and

inspection is located in a single chapter.

The Quick Reference Guide shows you all of the product’s system and assists in locating their chapters. Each chapter in turn has its own comprehensive Table of Contents.

The Periodic Maintenance Chart is located in the General Information chapter. The chart gives a time schedule for required maintenance operations.

If you want spark plug information, for example, go to the Periodic Maintenance Chart first. The chart tells you how frequently to clean and gap the plug.

Next, use the Quick Reference Guide to locate the electric System chapter. Then, use the Table of Contents on the first page of the chapter to find the Spark Plug section.

Whenever you see these WARNING and CAUTION symbols, heed their instructions! Always follow safe operating and maintenance practices.

This warning symbol identifies special

instructions or procedures which, if not correctly followed, could result in personal injury, or loss of life.

ACAUTION

This caution symbol identifies special

instructions or procedures which, if not

strictly observed, could result in damage to

or destruction of equipment.

Page 7

This manual contains four more symbols (in

addition to WARNING and CAUTION) which will

help you distinguish different types of information.

NOTE

o This note symbol indicates points of partic-

ular interest for more efficient and convenient operation.

Indicates a procedural step or work to be done.

olndicates a procedural sub-step or how to do the

work of the procedural step it follows. It also precedes the text of a WARNING, CAUTION, or

NOTE.

*Indicates a conditional step or what action to take

based on the results of the test or inspection in the procedural step or sub-step it follows.

In most chapters an exploded view illustration of

the system components follows the Table of

Contents.

instructions indicating which parts require specified tightening torque, oil, grease or a locking agent during assembly.

In these illustrations you will find the

Page 8

Quick Reference Guide

1 General Information I 1 1 Fuel System ( Cooling System 1 Engine Top End

Lubrication System ( 5

( Camshaft / Crankshaft 1 Electric System I Trouble Shooting

I 2 I 3

This quick reference guide will assist you in

locating a desired topic or procedure.

0 Bend the pages back to match the black tab

of the desired chapter number with the black tab on the edge at each table of contents page.

Refer to the sectional table of contents for

the exact pages to locate the specific topic

required.

Page 9

GENERAL INFORMATION l-l

General Information

Table of Contents

Before Servicing .........................................................................................................

Model Identification ....................................................................................................

General Specifications Periodic Maintenance Chart except U.S Periodic Maintenance Chart for

Torque and Locking Agent.. ......................................................................................

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

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

U.S. ......................................................................... .1-B

. ................................................... l-6

.I -2

l-5

1-7

.l -9

Page 10

1-2 GENERAL INFORMATION

Before Servicing

Before starting to service the engine, carefully read the applicable section to eliminate unnecessary work.

Photographs, diagrams, notes, cautions, warnings, and detailed descriptions have been included wherever

necessary. Nevertheless, even a detailed account has limitations, a certain amount of basic knowledge is required

for successful work.

Especially note the following:

(1) Dirt

Before removal and disassembly, clean the engine. Any dirt entering the engine, carburetor, or other parts, will work as an abrasive and shorten the life of engine. part, clean off any dust or metal filings.

:) Battery Ground

Remove the ground (-) lead from the battery before performing any disassembly operations on the equipment. This prevents:

(a) the possibility of accidentally turning the engine over while partially disassembled. (b) sparks at electrical connections which will occur when they are disconnected. (c) damage to electrical parts.

(3) Tightening Sequence

Generally, when installing a part with several bolts, nuts, or screws, start them all in their holes and tighten them to a snug fit. Then tighten them evenly, in a staggered sequence. This is to avoid distortion of the part and/or causing gas or oil leakage. Conversely, when loosening the bolts, nuts, or screws, first

loosen all of them by about a quarter of a turn and then remove them. Where there is a tightening sequence indication in this Service Manual, the bolts, nuts, or screws must be tightened in the order and method indicated.

(4) Torque

When torque values are given in this Service Manual, use them. Either too little or too much torque may

lead to serious damage. Use a good quality, reliable torque wrench.

(5) Force

Common sense should dictate how much force is necessary in assembly and disassembly. If a part seems especially difficult to remove or install, stop and examine what may be causing the problem. Whenever tapping is necessary, tap lightly using a wooden or plastic-faced mallet. Use an impact driver for screws

(particularly for the removal of screws held by a locking agent) in order to avoid damaging the heads.

(6) Edges

Watch for sharp edges, especially during major engine disassembly and assembly. Protect your hands

with gloves or a piece of thick cloth when lifting the engine or turning it over.

(7) High-Flash Point Solvent

A high-flash point solvent is recommended to reduce fire danger. A commercial solvent commonly available in North America is Stoddard solvent (generic name). Always follow manufacturer and container directions regarding the use of any solvent.

(8) Gasket, O-Ring

Do not reuse a gasket or O-ring once it has been in service.

should be free of foreign matter and perfectly smooth to avoid oil or compression leaks.

(9) Liquid Gasket, Non-Permanent Locking Agent

Follow manufacturer’s directions for cleaning and preparing surfaces where these compounds will be

used. Apply sparingly. Excessive amounts may block engine oil passages and cause serious damage. An

example of a non-permanent locking agent commonly available in North America is Loctite Lock’n Seal

(Blue).

(10) Press

A part installed using a press or driver, such as a journal, should first be coated with oil on its outer or inner circumference so that it will go into place smoothly.

(11) Ball Bearing

When installing a ball bearing , the bearing race which is affected by friction should be pushed by a suitable driver. This prevents severe stress on the balls and races, and prevents races and balls from being dented. Press a ball bearing until it stops at the stop in the hole or on the shaft.

For the same reason, before installing a new

The mating surfaces around the gasket

.-~

Page 11

GENERAL INFORMATION 1-3

(12) Oil Seal, Grease Seal

Replace any oil or grease seals that were removed with new ones, as removal generally damages seals.

When pressing in a seal which has manufacturer’s marks, press it in with the marks facing out. Seals should be pressed into place using a suitable driver, which contacts evenly with the side of seal, until the face of the seal is even with the end of the hole.

(13) Seal Guide

A seal guide is required for certain oil or grease seals during installation to avoid damage to the seal lips.

Before a shaft passes through a seal, apply a little oil, preferably high temperature grease on the lips to

reduce rubber to metal friction.

(14) Circlip, Retaining Ring

Replace any circlips and retaining rings that were removed with new ones, as removal weakens and deforms them. When installing circlips and retaining rings, take care to compress or expand them only enough to install them and no more.

(15) Cotter Pin

Replace any cotter pins that were removed with new ones, as removal deforms and breaks them.

(16) Lubrication

Engine wear is generally at its maximum while the engine is warming up and before all the rubbing surfaces have an adequate lubricative film. During assembly, oil or grease (whichever is more suitable)

should be applied to any rubbing surface which has lost its lubricative film. Old grease and dirty oil should

be cleaned off. Deteriorated grease has lost its lubricative quality and may contain abrasive foreign particles.

Don’t use just any oil or grease. Some oils and greases in particular should be used only in certain

applications and may be harmful if used in an application for which they are not intended. This manual

makes reference to molybdenum disulfide grease (MO& ) in the assembly of certain engine parts. Always

check manufacturer recommendations before using such special lubricants.

(17) Electrical Wires

All the electrical wires are either single-color or two-color and, with only a few exceptions, must be connected to wires of the same color. On any of the two-color wires there is a greater amount of one color and a lesser amount of a second color, so a two-color wire is identified by first the primary color and then the secondary color. For example, a yellow wire with thin red stripes is referred to as a “yellow/red” wire;

it would be a “red/yellow” wire if the colors were reversed to make red the main color.

Wire (cross-section)

Red

Wire Strands

Yellow

Red

(18) Replacement Parts

When there is a replacement instruction, replace these parts with new ones every time they are removed. There replacement parts will be damaged or lose their original function once removed.

(19) Inspection

When parts have been disassembled, visually inspect these parts for the following conditions or other damage. If there is any doubt as to the condition of them, replace them with new ones.

Abrasion Crack

Bent Dent Scratch

Color change Deterioration Seizure

(20) Specifications

Specification teams are defined as follows:

“Standards”: show dimensions or performances which brand-new parts or systems have.

“Service Limits” Indicate the usable limits. If the measurement shows excessive wear or deteriorated performance, replace the damaged parts.

Name of Wire Color

Yellow/Red

Hardening Warp

Wear

Page 12

l-4 GENERAL INFORMATION

KAWASAKI Multimeter:

KAWASAKI Multimeter (P/N 3951 OO-9803A) is recommended for the electrical system check because a

meter of other type may indicate different value.

Page 13

Model Identification

GENERAL INFORMATION 1-5

Cylinder Number Designation:

No.1 Cyl. is the right-hand cylinder viewed from the flywheel. No.2 Cyl. is the left-hand cylinder viewed from the flywheel.

Page 14

1-6 GENERAL INFORMATION

General Specifications

Items

Type of engine

Bore x Stroke Piston displacement Max. output

Direction of rotation Low idle speed except U.S. Low idle speed for U.S.

High idle speed except U.S. High idle speed for U.S. Ignition system RFI

Starting system

Charging system Carburetor Fuet pump

Air cleaner Governor

Lubrication system

“Oil filter

‘Oil pressure switch

Cooling system

Radiator

Dimensions (H x W x L) Dry weight 41.5 kg (91.5 lb)

Liquid-cooled, Horizontal shaft, OHV, 4-stroke, 9O”V-twin, Gasoline engine. 76 mm x 68 mm (2.99 in x 2.66 in) 617 mL (37.7 cu. in)

14.9 kW/3 600 rpm (20 HP/3 600 rpm)[SAE J1349]

Counterclockwise facing PTO shaft end

1550 -?r 100 (rpm)

1450 (rpm) to 1650 (rpm) 3600 + 75(rpm)

3600 (rpm)

Battery, Full transister, Fixed timing

Per Canada and U.S.A. requirements Shift type electric starter 12 V - 20 amps with regulator

Down draft type, Fixed main jet Electra magnetic pump (in-line type) Dual stage element

All speed mechanical fly weights

Pressure feed by positive displacement pump Cartridge type full flow filter ON-OFF switch Pressurized forced circulation type

3-rows with louverless corrugated fin 624 mm x 448 mm x 556 mm

(24.6 in x 17.6 in x 21.9 in)

FD620D

‘Specifications are subject to change without notice.

Page 15

GENERAL INFORMATION l-7

Periodic Maintenance Chart except U.S.

To ensure satisfactory operation over an extended period of time, any engine requires normal maintenance regular intervals. The Periodic Maintenance Chart below shows periodic inspection and maintenance items\ and suitable intervals. The bullet mark (0) designates that the corresponding item should be performed at that interval.

Some adjustments require the use of special tools or other equipment. An electronic tachometer will facilitate

setting idle and running speeds.

Always remove the spark plug cap from spark plug when servicing the engine to prevent accldental starting.

INTERVAL

MAINTENANCE

Check and add engine oil, coolant and fuel Check for loose or lost nuts and screws Check for fuel, oil and coolant leakage Check battery electrolyte level Check or clean air intake screen Clean air cleaner foam element (1) Clean air cleaner paper element (I )

Change engine oil Tighten nuts and screws Clean and regap spark plug

Change oil filter

Change air cleaner paper element (1)

Change spark plugs

Clean combustion chamber*

Inspect radiator and hoses*

Check fan belt conditions and tension*

Change coolant* Valve maintenance*

Check and lap valve seating surface*

Dally

I I I

I I I I I I

First Every Every Every Every Every Every

20 hr. 25 hr. 50 hr. 100 hr. 200hr. 3OOhr 400 hr.

a 0 0

I 0 I I 0 I

( 0 1

0 0

l l l

I.1 I

( 0 )

(1) Service more frequently under dusty conditions.

These items must be performed with the proper tools. See your authorized Kawasaki engine dealer for service, unless you have the proper equipment and mechanical proficiency.

Page 16

1-8 GENERAL INFORMATION

Periodic Maintenance Chart

To ensure satisfactory operation over an extended period of time, any engine requires normal maintenance regular intervals. The Periodic Maintenance Chart below shows periodic inspection and maintenance items and suitable intervals. The bullet mark (0) designates that the corresponding item should be performed at that interval.

Some adjustments require the use of special tools or other equipment. An electronic tachometer will facilitate

setting idle and running speeds.

Always remove the spark plug cap from spark plug when servicing the engine to prevent accidental starting.

MAINTENANCE

for

U.S.

K Clean and lap valve seating surface K Inspect radiator and hoses K Check fan belt conditions and tension K Change coolant

Note: The service intervals indicated are to be used as a guide. Service should be performed more frequently as

necessary by operating condition. * : Service more frequently.under dusty conditions. K : Have an authorized Kawasaki engine dealer perform those services.

0 0

Page 17

GENERAL INFORMATION l-9

Torque and Locking Agent

The following tables list the tightening torque for the major fasteners, and the parts requiring use of a non-permanent

locking agent or liquid gasket.

Letters used in the “Remarks” column mean*

L : Apply a non-permanent locking agent to the threads. M : Apply a molybdenum disulfide lubricant (grease or oil) to the threads, seated surface, or washer. 0 : Apply an oil to the threads, seated surface, or washer.

S : Tighten the fasteners following the specified sequence.

Fastener

N-m

Torque Remarks

kg-m ft-lb

Fuel System:

Carburetor Mounting Nuts

Governor Arm Nut

Fuel Shut-Off Solenoid Valve

17.0

7.8

9.8

1.7

0.8

12.0

69 in-lb

1 .o 7.0

Cooling System:

Radiator Mounting Bolts Cooling Fan Shaft Nut Water Pump Cover Bolts Therm0 Switch

17.0

20.0

7.8

27.0

1.7 12.0

2.0 14.5

0.8 69 in-lb

2.8 20.0

Engine Top End:

Cylinder Head Bolts and Nuts Valve Clearance Adjust Nuts Spark Piugs

21 .o

8.8

25.0

2.1 15.0

0.9 78 in-lb

2.5 18.0

Lubrication System:

Oil Drain Plug Oil Pressure Switch

23.0

15.0

2.3

16.5

1.5 11 .o L

Camshaft/Crankshaft:

Case Cover to Block Bolts

Con-Rod Cap Bolts

21 .o 21 .o

2.1

15.0 S

2.1 15.0 0

Electrical System:

Flywheel Nut

Starter Motor “B” Terminal

110.0

9.8

11 .o 80.0

1 .o 7.0

The table below, relating tightening torque to thread diameter, lists the basic torque for the bolts and nuts. Use this table for only the bolts and nuts which do not require a specific torque value. All

of the values are for use with dry solvent-cleaned

threads.

Bark Toraue for General Fasteners

hreads

dia.

(mm)

4 1.2-2.2 5 3.4-4.9 6 5.9-7.8 8 14-19

N-m

Torque

Page 18

Fuel System

Table of Contents

FUEL SYSTEM 2-l

Exploded View Specifications.. Governor Link Mechanism

Control Panel Assembly/Removal Control Panel Assembly Installation Notes Governor Am, Removal Governor Arm Installation Governor Assembly Removal

Governor Assembly Installation Notes Governor Assembly Inspection Governor Shaft Removal Governor Shaft Installation Notes

Carburetor

Fuel and Air Flow

Fuel Shut Off Solenoid Valve ..............................................................................................

Idle Mixture Screw (Pilot Screw) and Idle Speed Adjustment Fast Idle Speed Adjustment.. High Altitude Operation Main Jet Replacement.. Fuel System Cleanliness Carburetor Removal Installation Notes

Disassembly Assembly Notes ............................................................................................

Cleaning

Inspection.. Fuel Shut-Off Solenoid Valve Test

Intake Manifold..

Removal. ..............................................................................................................................

Installation Notes inspection

Fuel Pump..

Fuel Pump Test ..................................................................................................................

Air Cleaner.. .......................................................................................................................... ...2-17

Element Removal.. ............................................................................................................. .2-l 7

Element Installation Notes.. Element Cleaning and Inspection Cleaner Body and Bracket Removal

Cleaner Body and Bracket Installation Notes

Housing (Case and Body) Inspection

.......................................................................................................................... 2-2

.......................................................................................................................... 2-4

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

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

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

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

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

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

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

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

.................................................................................................................................. 2-8

.......................................... 0 ......................................................................

............................................................................................... 2-9

..................................................................................................... 2-10

Inspection

........................................................................................................... 2-l 1

............................................................................................................... 2-l 1

............................................................................................................................. 2-12

......................................................................................................................... 2-l 3

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

..................................................................................................................... 2-l 5

............................................................................................................... 2-l 5

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

.......................................................................................................................... ...2-16

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

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

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

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

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

.................................................................................. 2-l 1

................................................................................ ..2-18

.................................................................... 2-18

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

2-5 2-5

.2-5

2-5 2-5 2-6

2-6

2-6 .2-6 .2-7

2-8 2-8 2-9

2-l 2

2-14 2-l 5

..2-15

2-16

2-17 2-17

2-18

Page 19

2-2 FUEL SYSTEM

Exploded View

Tl: 2.00 N-m (0.20kg-m,17.0 in-lb)

(Stopper Screw)

T2: 1.16 N-m (0.13 kg-m, 10.3 in-lb)

(Drain Screw)

T3: 0.66 N-m (0.90 kg-m, 7.6 in-lb)

(Throttle Valve Screws)

T4: 9.80 N-m (1 .OO kg-m, 87.0 In-lb)

(Solenoid Valve)

T5: 1.00 N-m (0.10 kg-m, 8.9 in-lb)

(Main Jet)

T6: 2.94 N-m (0.30 Kg-m, 26.0 In-lb)

(Air Hone Mounting Screws)

T7: 1.00 N-m (0.10 kg-m, 8.9 in-lb)

(Pilot Ah Jet)

T8: 0.88 N-m (0.90 kg-m, 7.8 in-lb)

(Choke Valve Screw)

l8: 1.00 N-m (0.10 kg-m, 8.9 in-lb)

(Main Air Jet)

TlO: 17.00 N-m (1.7 kg-m, 12.0 Mb)

(Carb. Mounting Nuts)

Page 20

FUEL SYSTEM 2-3

Tl: 7.6 N-m (0.8 kg-m, 89 in-lb)

0: Apply engine oil

Page 21

2-4 FUEL SYSTEM Specifications

Item

Carburetor Specifications:

Make/type Main bore diameter

Venturi diameter

Main jet (MJ) Pilot jet (PJ) Main air jet (MAJ) Pilot air jet (PAJ) Pilot Screw turns out (PS) (Idle mixture screw turns out) Float level

Idle Speed except U.S.

Low idle speed High idle speed

Idle Speed for U.S.

Low idle speed High idle speed

Air Cleaner:

Type

Pre-cleaner

Two-stage cleaner

Standard

TEIKEI/FD22K-1 A 26 mm (1.02 in) 22 mm (0.87 in) #112

#58

#1.8 #0.9 1 314

Float parallel to carburetor body

1550 _+ 100 (rpm)

3600 a 75(rpm)

1450 (rpm) to 1650 (rpm)

3600 (rpm)

Dual stage filtration system Foam element Paper element

Fuel:

Fuel requirement except U.S. Fuel requirement

Fuel Pump:

Type

Rated voltage Delivery (MIN)

Shut-off delivery pressure

Governor:

Type

for U.S.

Leaded or unleaded automotive grade gasoline

Unleaded regular grade gasoline

Electra-magnetic Pump (in-line type) 12VDC 400 mL (0.4 qt)/(MIN) at free flow

19.6 to 26.5 kPa (2.8 to 3.8 psi)

Flyweight all speed governor

Page 22

Governor Link Mechanism Control Panel Assembly/Removal

0 Remove:

Air Cleaner (see Air Cleaner)

Muffler (see Muffler Assembly Removal)

Carburetor(see Carburetor Removal)

OUnscrew the M6 mounting screws (A) and take off the control panel

assembly (B) while unhooking the governor spring (C) end loop at the middle of the governor arm(D).

NOTE

0 Note the position of the different length of the screws. The longer

screw has a collar (E) between control panel and the crankcase.

Control Panel Assembly Installation Notes

Before installing the control panel assembly, check to see that the choke lever and engine speed control lever move smoothly all the ways.

*If any part is worn or damaged, replace the control panel assembly.

After installation, adjust the low and fast idle speeds to the specifications (see Idle Speed and Fast Idle Speed adjustment).

A. Choke Lever C. Choke Spring

B. Engine Speed Control Lever D. Governor Spring

FUEL SYSTEM 2-5

Governor Arm Removal

0 Remove:

Control Panel Assembly

Loosen the clamp nut, and take off the governor arm.

A. Clamp Nut B. Governor Arm

Governor Arm Installation

install the governor arm onto the governor shaft temporarily.

install the control panel assembly, and connect the governor arm with the governor spring.

0 Install the carburetor except for the air cleaner bracket.

Be sure the link spring around the throttle link rod is inplace and that it pulls the governor arm and throttle lever each other.

Loosen the clamp nut on the governor arm enough to move the governor shaft.

Turn Top end of the governor arm counterclockwise to fully open the carburetor throttle valve and hold it there.

@Turn the governor shaft counterclockwise by inserting a needle into

shaft end hole. Fully turn the shaft to end of its travel and tighten the clamp nut to the specification (see Exploded View).

Be sure the governor shaft extend from the governor arm is approximately 7mm (0.3in).

1. Link Spring 6. Governor Shaft

2. Throttle Link Rod 7. Clamp Nut

3. Throttle Lever 6. Small Hole

4. Governor Arm 9. Governor Sleeve

5. Carburetor (Controll panel is removed for clarity)

Page 23

2-6 FUEL SYSTEM

Governor Assembly Removal

@Split the crankcase (see Crankcase Splitting in the Camshaft/Crank-

shaft chapter).

@Remove the governor assembly (A) with the sleeve (B) by prying the

gear with’ two proper size screw drivers.

OTo avoid damaging the parting surface of the casecover, use a

suitable soft mats (C) as shown.

ACAUTION

Do not remove the governor assembly unless it is necessary. Once

It has been removed, it must be replaced.

oRemove the thrust washer.

Governor Assembly Installation Notes

OFit the sleeve into the governor assembly, and install them as a set.

NOTE ,

0 The sleeve and the governor assembly cannot be installed separately.

Push the set onto the shaft until inner flange snaps into the groove securely.

1. Sleeve

2. Governor Assembly

3. Inner Flange

4. Thrust Washer

5. Groove

6. Shaft

@Spin the governor assembly by hand and check that the flyweights

operate freely and the center sleeve moves outward.

Governor Assembly Inspection

OVisually check the assembly for wear and damage.

*If any part is worm or damaged, replace the assembly.

Governor Shaft Removal

0 Remove:

Camshaft (see Camshaft Tappet Removal in the camshaft/Crankshaft

chapter). 0 Unscrew the governor arm clamp nut, and remove the governor arm. ofurn the governor shaft clockwise l/4 turn to remove governor shaft.

NOTE

O/t is not necessary to remove the governor shaft unless it is being

replaced.

0 Replace the oil seal only if the lip shows signs of leakage or it has been

damaged.

Page 24

The oil seal must be assembled, with seal lip towards inside of the

engine.

Press in the oil seal 1 .Omm (0.04 in) below the crankcase surface.

1. Governor Shaft

2. Oil Seal 5. Crankcase

3. Shaft Arm

4. Projections

Governor Shaft Installation Notes

install the governor shaft (A) by properly positioning shaft arm between projections (B) as shown (see above PHOTO).

NOTE

olnstall the governor shaft before installing the camshaft to the ‘>

crankcase.

Check that the governor shaft moves freely in its operating range.

FUEL SYSTEM 2-7

Page 25

2-8 FUEL SYSTEM

Carburetor

Fuel and Air Flow

The main system of the carburetor consists of the main jet, main

nozzle, and the main air passage (main air jet). The main system meters fuel to the engine during moderate to heavy load conditions. Fuel flows through the main jet and into the main nozzle, where it is joined by air

from the main air passage (main air jet). The resulting mixture flows out the end of the main nozzle into the carburetor bore, where it is atomized by the high speed air flow, and carried into the engine.

The pilot system includes the pilot jet, pilot screw (Idle mixture screw), pilot air jet, pilot outlet, and the bypass outlet. The pilot system meters the fuel/air mixture while the engine is idling and running under a light lead. Under these conditions there is very little air flow through the carburetor bore; so little that it is not enough to draw fuel through the

main system of the carburetor and atomize it. Instead, the fuel is drawn

through the pilot system, since the nearly closed throttle valve causes

high speed air flow past the pilot outlet and bypass holes(even at low

engine speed).

Fuel flow in the pilot system is metered by the pilot jet. Air for better atomization is admitted via the pilot air jet in the mouth of the carburetor. The fuel/air mixture passes into the bore of the carburetor downstream

of the throttle valve through the bypass holes and pilot outlet. While the throttle valve is almost closed, it covers the small bypass holes opening into the bore from the pilot system. As the throttle valve begins to open, it uncovers the bypass holes, allowing more fuel/air mixture to flow. The extra flow is needed because the engine starts to run faster as the throttle is opened. The pilot screw controls the amount of fuel/air mixture allowed through the pilot outlet, but dose not meter the bypass holes. A moderate amount of air comes in around the throttle valve at an idle, so adjusting the pilot screw changes the fuel/air ratio. Turning the pilot screw (Idle mixture screw) out (Counterclockwise) enrichens the mixture; turning it in (clockwise) leans the mixture.

1. Main Jet 8. Bypass Holes

2. Main Air Jet 9. Pilot Outlet

3. Emarsion Tube 10. Pilot Screw

4. Float (Idle Mixture Screw)

5. Ball Plugs 11. Throttle Valve

6. Pilot Jet

7. Pilot Air Jet 13. Plate Plug

12. Main Nozzle

Main Fuel Flow

----

Pilot Fuel Flow

Fuel Shut Off Solenoid Valve

To avoid after firing when stopping the engine, a solenoid actuated fuel shut off valve is installed in the carburetor bowl. The valve shuts off the fuel supply to the main jet simultaneously when the switch key turned to the “OFF” position.

The valve opens automatically when the switch key is turned to the

“Run” position.

1. Solenoid Valve

2. Main Jet

Page 26

Idle Mixture Screw (Pilot Screw) and Idle Speed AcQustment

ACAlJTtON

Do not attempt to adjust idle mixture screw with air cleaner removed

Stop the engine.

@Turn the idle mixture screw (A) all the way in until it seats lightly.

ACAlJTfON

Do not turn tfte idle mixture screw in too far or the carburetor body will be damaged and require replacement

@Back the idle mixture screw out the specified number of turns (1 3/4).

This setting is approximately correct. To make fine adjustment, follow the steps below.

Disconnect all possible external loads from the engine.

Start the engine and warm it up thoroughly.

FUEL SYSTEM 2-9

Always keep your hands clear of the moving

@Move the throttle lever on dash in the idle position, and hold the

throttle lever on the carburetor in closed position (turn the governor

arm clockwise all the way) and adjust the idle speed screw (A) until the engine idles at specified speed.

Keep on throttle lever on the carburetor in the closed position, and search for the point at which the engine speed gets the highest by slowly turning the idle mixture screw in or out and then turn the idle

mixture screw back out additional l/4 turn.

0 Make adjustment by turning the idle speed screw so that the engine

may be kept at specified idle speed while keeping the on the carburetor in the closed position.

idle Mixture Screw Turns Out

1 3/4 (nearly about) idle Speed except U.S. 1550 + 100 (rpm)

idle Speed for U.S. 1450 to 1650 (rpm)

parts

throttle lever

NOTE

OA remote throttle control cable nlust be made the idle

respectively

1. Throttle Cable

2. Choke Cable

3. Idle Position

4. Throttle Lever (Carb.)

correspond to that of the equipment.

5. Governor Arm

6. Idle Speed Screw

7. Idle Mixture Screw

speed

Fast Idle Speed Ac#ustment

NOTE

OFast idle speed adjustment should be made after the idle speed

adjustment is performed.

ACAUllON

Do not adjust fast idle speed with the air cleaner removed

Start and warm up the engine thoroughly.

Page 27

2-10 FUEL SYSTEM

Always keep your hands clear of the moving parts.

Move the throttle lever on dash in the fast idle position and leave it

there.

@Loosen two M6 control panel mounting bolts enough to move the

control panel assembly.

Carefully move the control panel assembly left or right to obtain the specified fast idle speed.

*Tighten the M6 Mounting bolts.

Fast Speed

3600 f 75 rpm

Check the idle speed, and readjust the idle speed if necessary.

ACAlJTlON

Be sure to make the idle and fast idle speeds respectively

correspond to those of the equipment.

A. Control Panel C. Fast Idle

B. M6 Mounting Bolts (Air cleaner is removed for clarity)

D. Open Choke

High Altitude Operation

At high altitude, the standard carburetor air-fuel mixture will be excessively rich. Performance will decrease, and fuel consumption will increase. High altitude performance can be improved by installihg a smaller diameter main-jet in the carburetor and readjusting the pilot screw (idle mixture screw) to meet good idling and idle speed is the specified rpm.

NOTE

0 The main jet high altitude kits are available if the equipment is to be

used in the high altitudes. ends of the main jets.

High Altitude Main Jet

Altitude 0 y 1000 m (o-3000 ft) 1000 - 2000 m (3000 -6000 ft) #llO 2000 m (6000 ft) and higher #lOS

The main jet numbers are stamped on

Main Jet No.

#112 (STD)

Main Jet Replacement

Place the engine (equipment) on a level surface.

Close the fuel shut off valve in the equipment.

Drain the fuel in the carburetor completely by unscrewing the drain

screw (C) at the bottom of the float chamber.

ORemove the carburetor (see Carburetor Removal).

Unscrew the solenoid valve (A), and take off the valve and gasket.

@Using a proper blade screw driver, carefully replace the main jet (B)

with a new one for altitude expected.

@Tighten the main jet to the specification (see Carburetor Disassembly

Assembly Notes).

install the gasket and solenoid valve.

Page 28

f uef System Cleanliness inspection

Gasoline is extremely flammable and can be explosive under certain conditions. Turn the ignition switch OFF. Do not smoke. Make sure the area is well ventilated and free from any source of flame or sparks; this includes any appliance with a pilot light.

Place a suitable drain hose (B) under the drain screw (A) on the

carburetor.

Run the lower end of the hose into a container.

Turn out the drain screw a few turns to drain the carburetor and check to see if water or dirt has accumulated in the carburetor.

Tighten the drain screw.

*If any water or dirt come out, clean the carburetor (see carburetor

Cleaning), and fuel tank, and check the fuel filter.

FUEL SYSTEM 2-11

Carburetor Removal

0 Remove:

Air Cleaner and Related Parts (see Air Cleaner). @Turn the fuel shut off valve to the OFF position. 0 Drain the carburetor. 0 Disconnect the fuel tube at the fuel inlet joint (A) of the carburetor. 0 Disconnect the solenoid valve lead terminal.

Unscrew the carburetor mounting nuts.

Unhook the throttle link spring (B) at the governor arm (C) top end

with a long nose plier.

Unhook the throttle and choke link rods (D.E) at the top ends of their

arms while lifting off the carburetor.

Installation Notes

Clean the mating surfaces of the carburetor and intake manifold and

fit a new gasket.

Take care not to bend the throttle and choke link rods during installation. Make sure the link spring around the throttle link rod is inplace

and that it pulls the governor arm and carburetor throttle lever toward

each other.

Adjust:

Carburetor Idle Mixture screw

Idle Speed

Page 29

2-12 FUEL SYSTEM

Disassembly Assembly Notes

@Refer to the illustration shown for disassembly and assembly. @There are a number of the plate or boll plugs in the carburetor. None

of these should be removed.

@Turn in the idle mixture screw and count the number of turns until it

seats fully but not tightly, and then remove the screw. This is to set the screw to its original position when assembling.

Turn the idle mixture screw all the way in until it seats lightly, and then

back it out the same number of turns counted during disassembly.

install the throttle valve on the shaft as the numerical mark on the valve

facing out side.

Note the metering hole in the choke valve, install the choke valve on the shaft so that the metering hole towards fuel inlet joint of the carburetor.

Drive in the float pin so that the pin extends the same distance on both side of the float hinge bracket.

The fuel inlet valve seat is pressed into the carburetor body and is not

replaceable.

When assembling the carburetor parts which are attached to the carburetor with the recommended tightening torque of a bolts and screws. (see Exploded View)

1. Choke Shaft 19. Spring

2. Seal 20. Screws

3. Collar

4. Collar 22. Solenoid Valve

5. Air Hone 23. Gasket

6. Emarsion Tube

7. Float 25. Carb. Body

8. Gasket 26. Carb. Mounting Nuts

9. Pilot Jet 27. Float Pin

10. Screw 28. Float Valve

11. Stopper 29. Screws

12. Throttle Shaft 30. Pilot Air Jet

13. Seal 31. O-ring

14. Spring

15. Idle Speed Screw 33. Choke Valve

16. Spring 34. Main Air Jet

17. Pilot Screw

18. Drain Screw

21. Throttle Valve

24. Main Jet

32. Screw

Cleaning

Clean the carburetor in a well-ventilated area and take care that there is no spark or flame anywhere near the working area: this Included any appliance wlth a pilot light. Because of the danger of highly flammable liquids, do not use gasoline or low flash-point solvents to clean the carburetors.

ACAUTION

Do not use compressed air on an assembled carburetor, the float may be crushed by the pressure. Remove as many rubber or plastk parts from the carburetor as possible before cleaning the carburetor wltft a cleaning solution. This will prevent damage or deterloratkn of the parts. The carburetor body has plastic parts that cannot be removed. Do not use a strong carburetor cleaning solution which could attack these parts; instead, use a mild high flash-point cleaning solution safe for plastic parts. Do not use wire or any other hard Instrument to clean carburetor parts, especially jets, as they may be damaged.

Page 30

0 Disassemble the carburetor.

immerse all the carburetor metal parts in a carburetor cleaning solution and clean them.

Rinse the carburetor parts in water and dry them with compressed air.

Do not use a rags or paper to dry parts. Lint may plug the holes or passages.

0 Blow air through the holes and fuel passages with the compressed air.

All holes must be open.

Assemble the carburetor.

Inspection

Gasoline is extremely flammable and can be explosive under certain Turn the lgnilion switch OFF. Do not smoke. Make sure the area Is well ventilated and free from any source of flame or sparks; this includes any appliance with a pilot light.

*Inspect the carburetor body for damage. Flange sealing surfaces

should be smooth and free of burrs and nicks. Replace the gasket if necessary.

Turn the throttle and choke shafts to check that the throttle and choke butterfly valves move smoothly.

*If the valves do not more smoothly, replace the carburetor body and/or

throttle shaft and choke shaft assembly.

Check that the gasket on the carburetor body.

*if the gasket is not in good condition, replace it.

Check the other parts of the carburetor for wear or damage. Replace the part if necessary.

Clean and check the float level as follows.

FUEL SYSTEM 2-13

ACAUTlON

Do not push down on the float durlng float level checking.

With the float (3) assembly installed onto the air hone (I), hold the air hone upside down at an eye level. Gently support the float with a finger and bring it down slowly so that the float arm tab (4) just touches the float valve needle (5). The float lower surface should be parallel with the carburetor body to the air’hone mating surfaces (2).

*If the float position is not correct, bend the tab as required for correct

adjustment.

@Inspect the inlet needle valve for excessive wear or damage. The tip

should be smooth, without any grooves, scratches, or tears. The rod at the other end of the needle should move smoothly when push in and released.

*If either the needle or the seat is worn or damaged, replace the float

assembly and carburetor body as a set.

Bad

Page 31

2-14 FUEL SYSTEM

@Inspect the tapered portion (B) of the screw for wear or damage. @Inspect the tapered portion (B) of the screw for wear or damage.

*If the pilot screw (A) is worn or damaged, on the taper portion, replace *If the pilot screw (A) is worn or damaged, on the taper portion, replace

it. it.

Check the spring for weakened condition, replace it, if necessary.

Fuel Shut- Off Solenoid Valve Test

@Unscrew the fuel shut off valve and remove the valve. @Connect a 12 VDC source to the solenoid as shown.

*If the actuate solenoid plunger (Needle Valve) does not pop in when

the Test Voltage is applied, replace it.

NOTE

Olf

may be necessary to push the plunger slightly for the plunger to

withdraw.

Page 32

Intake Manifold

Removal:

0 Remove:

Air Cleaner

Carburetor Control Panel Assembly

@Drain the coolant in the engine (see coolant Draining)

Unscrew the manifold mounting bolts in numerical sequence, l/4 turn at a time, until all bolts are loose.

*If the mounting bolts removal sequence is not followed, manifold

mating surfaces may be warped.

0 Remove the manifold and gaskets.

A. No.1 C.yi. Head

B. No. 2 Cyl. Head D. Intake Manifold

C. Gaskets

FUEL SYSTEM 2-15

Installation Notes

@Before assembling the manifold, install the cylinder heads on each

cylinder and tighten the head bolts in the specified sequence temporarily (see Cylinder Head Installation Notes).

Place a new gaskets on each mating surface, and install the manifold.

Follow the sequence shown, tighten the mounting bolts to 4 N-m (35 in-lb).

Tighten the bolts in sequence 3 N-m (26 in-lb) at a time until the torque on each bolt is 6.0 N-m (52 in-lb).

Note the position of the different length of bolts.

Then tighten the cylinder head bolts to the specified torque.

Head Assembly Installation Note).

Cylinder

Inspection

Visually inspect the coolant passage in the manifold for deposits or corrosion in layers inside the passage, clean the passage if necessary.

@An improperly installed gaskets can cause coolant leakage and air

drawn into the induction passage. Check the gaskets for correct

installation.

NOTE

OSmall coolant leaks appear only as a rust, corrosion or stain.

inspect the intake manifold for cracks or porous casting.

Cracks not visible to the eye may be detected by coating the suspected area with mixture of 25 % kelosene and 75 % light engine oil.

Wipe the area dry and immediately apply a coating of zinc oxide dissolved in wood alcohol.

become discolored at the defective area.

*If a cracks is present in the intake manifold, replace it.

inspect the gasket surfaces for burrs and nicks.

If a cracks is present, the coating will

Page 33

2-16 FUEL SYSTEM

Fuel Pump

The optional location fuel pump (A) is not installed in the engine

when shipped. The fuel pump must be installed onto an equipment as

inlet

and

outlet pipes are horizontal or vertical (Outlet is up side).

The fuel pump cannot be disassembled ,if any damage for the pump

is appeared replace it with a new one.

Fuel Pump Test

Before this test, be sure the battery is fully charged.

explosive. Do not expose to spark or flame. Personal

lniurv could result.

0 Disconnect and plug the fuel pump outlet pipe. @Connect proper pressure gauge to the fuel pump outlet pipe.

Turn the engine switch to the “RUN” position, the fuel pump will operates. Record the pressure reading. Stop the fuel pump.

ORemove the pressure gauge and connect the outlet fuel tube.

Disconnect the fuel pump outlet tube from the carburetor inlet.

Put the tube end in a graduated container.

Run the fuel pump for 30 seconds. Stop the fuel pump.

container measurement.

Compare the readings to the specifications.

*If low, check for clogged or damaged tubes, fuel filter, or fuel tank.

Replace fauln/ fuel pump. Minimum Specifications

Fuel Pressure

Fuel Flow 160mU30 seconds

19kPa (2.76 psi)

Record the

l_,l “”

Page 34

Air Cleaner Element Removal

ORemove the wing bolts, washers and air cleaner case.

Take off the air cleaner elements from the body.

A. Wing Bolts D. Elements

B. Washers E. Body

C. Case

Element Installation Notes

install the elements correctly on the air cleaner body.

The elements can be installed either way on the air cleaner body. sure the elements is inplace on the air cleaner body.

FUEL SYSTEM 2-17

Element Cleaning and Inspection

NOTE

0 In dusty areas, the elements should be cleaned more frequently than

the recommended intervals.

Clean the element In a well-ventilated area, and take ample care that there are no sparks or flame anywhere near the worklng area.

Because of the danger of highly flammable Ilqulds, do not use

gasoline or a low flash-point solvent to clean Ihe element.

ORemove the air cleaner element, and separate the foam element (A)

from the paper element (B).

Clean the foam element in a bath of detergent and water, and then dry it with compressed air or by shaking it.

After cleaning, saturate the foam element with clean engine oil, squeeze out the excess, then wrap it in a clean rag and squeeze it as dry as possible. Be careful not to tear the foam element.

Clean the paper element by tapping it gently on a flat surface to remove dust. If the element is very dirty, replace it with a new one or wash the

element in a detergent and water.

Rinse the element until a water is clear. Let the element air-dry thoroughly before install it.

ACAUTION

Do not use compressed alr to clean the paper element.

paper element.

Do not oil the

Page 35

2-18 FUEL SYSTEM

Cleaner Body and Bracket Removal

*Remove the cleaner body mounting screws, spring washers and plain

washers.

NOTE

0 Do not let the screws, spring washers and plain washers fall into the

carburetor bore.

*Pull the breather hose off the pipe at the back of the body, and remove

the cleaner body.

@Unscrew the carburetor mounting nuts, then take off the bracket.

A. Screws

B. Spring Washers F. Breather Hose

C. Plain Washers G. Pipe

D. Body

E. Bracket

H. U-bend Hose LMountinag Nuts

Cleaner Body and Bracket Installation Notes

When assemljling the cleaner body onto the bracket, do not let *the screws, spring washers and plain washers fall Into the carburetor

bore.

Note the positions of different length of screws and different diameter

of the plain washers.

@Install the U-bend breather hose so that the end of the hose positions

just above the carburetor bore.

Connect the breather hose from the

of the cleaner body.

ACAUTION

crankcase

to the pipe at the back

Housing (Case and Body) inspection

Clean the housing with detergent and water and dry thoroughly.

@Check the housing for deformation or other damage. The housing

must seal well and permit only filtered air to reach the carburetor.

*If the housing is damaged, it must be replaced.

Check that no foreign material is otistructing the air passage.

Page 36

COOLING SYSTEM 3-1

Cooling System

Table of Contents

Exploded View

Specifications ..............................................................................................................

Cooling System

Coolant..

Coolant Deterioration

Coolant Level Inspection ........................................................................................

Coolant Draining .....................................................................................................

Coolant Filling.. ......................................................................................................

Air Bleeding ........................................................................................................... .3-8

Visual Leak inspection

Cooling System Pressure Testing.. ........................................................................

Flushing

Disassembly and Assembly Precautions

Water Pump

Water Pump Removal

Installation Notes

Disassembly

Pump Parts Inspection .........................................................................................

Assembly Notes ....................................................................................................

Radiator

Removal ................................................................................................................

Radiator Inspection.. Radiator Cap Inspection Radiator Hose Inspection

Radiator Hose Installation Notes ..........................................................................

Cooling Fan, Fan Belt

Belt Tension Check Belt Replacement Notes

Removal ................................................................................................................

Installation Notes

Inspection ................................................................ +. .......................................... .3-l 6

Fan Bearing Removal ...........................................................................................

Fan Bearing Installation Notes..

Thermostat..

Thermostat Removal

Thermostat Inspection ......................................................................................... .3-l 8

Therm0 Switch

Therm0 Switch Removal and Installation Notes therm0 Switch Inspection

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

........................................................................................................... 3-5

...................................................................................................................... 3-6

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

............................................................................................ 3-8

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

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

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

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

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

.......................................................................................................... 3-l 0

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

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

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

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

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

............................................................................................. ..3-15

..................................................................................... ..3-15

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

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

............................................................................................................... 3-18

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

........................................................................................................ ..3-19

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

.................................................................................. ..3-19

3-2 3-4

3-6 3-6 3-6

.3-7

.3-8

3-9

.3-9

3-10

3-10 3-10

3-I I 3-l 1

3-l 2 3-12

.3-l 2

3-13 3-l 4 3-14 3-l 5

3-16 3-16

3-17

.3-l 7

3-18

3-19

Page 37

3-2 COOLING SYSTEM

ExDloded View

D: Apply engine oil G: Apply grease 2 Apply a non-permanent locking

agent to the threads

Tl: 27 N-m (2.8 kg-m, 20 Mb)

(Therm0 Switch)

T2: 20 N-m (2.0 kg-m, 14.5 &lb)

(Fan Shafl Nut)

T3: 21 N-m (2.1 kg-m, 15.0 A-lb)

(Pump Cover Bolt M8)

Page 38

COOLING SYSTEM 3-3

Tl: 2.0 N-m (0.2 kg-m, 17 in-lb) Tl: 2.0 N-m (0.2 kg-m, 17 In-lb)

(Finger Tight) (Finger Tight)

T2: 14 N-m (1.4 kg-m, 10 Mb) T2: 14 N-m (1.4 kg-m, 10 Mb)

(Drain Screws [Black Head]) (Drain Screws [Black Head])

Page 39

3-4 COOLING SYSTEM

Specifications

item Standard

‘Coolant:

Type

Color Green Mixed ratio 50% solution of ethylene glycol Freezing point -35°C (-31 “F)

Total amount

Radiator Cap Relief Pressure:

Pressure valve (positive) 73.3 to 102.7 kPa (10.6 to 14.9 psi)

Vacuum Valve (negative) 4.90 kPa (0.71 psi)

Thermostat:

Valve openning temperature 63 to 66°C (145 to 150°F) Valve full openning lift not less than 7mm (0.28 in) at 80°C (176°F)

Therm0 Switch:

Detect Temperature 108 to 114°C (226 to 237°F)

“A permanent type of antifreeze is not installed in the cooling system when shipped.

Permanent type of antifreeze for aluminum engine and radiator

2.7 L (0.7 us gallon)

Page 40

Cooling System

This engine is equipped with a highly efficient pressurized cooling system using a thermostat to maintain an optimum operating temperature. Coolant bypasses the closed thermostat when cold until operating temperature is attained, causing the engine to warm up more quickly. If the coolant temperature becomes too high, a therm0 switch on the engine activates the coolant warning lamp to alert the operator or cooling problem.

1. Water Pump

2. Cylinder Jackets

3. Cylinder Heads

4. Intake Manifold

5. Thermostat

6. Bypass Tube

7. Therm0 Switch

8. Radiator

9. Radiator Cap

10. Cooling Fan

11. Cylinder Block

COOLING SYSTEM 3-5

Page 41

3-6 COOLING SYSTEM

Coolant Coolant Deterioration

@Visually inspect the coolant in the radiator.

Olf

whitish cotton-like wafts are observed, aluminum parts in the cooling system are corroded. If the coolant is brown, iron or steel parts are rusting. In either case, flush the cooling system.

0 If the coolant gives off an abnormal smell when changing, check for a

cooling system leak. It may be caused by exhaust gas leaking in to the cooling system.

Coolant Level Inspection

@Put the engine on a level surface. ORemove the radiator cap turning it counterclockwise and check the

coolant level in the radiator.

Always allow the engine to tool before removing the radiator cap. Then remove the cap slowly and carefully to avoid a possible fast

’ discharge of hot coolant which could cause severe burns.

Coolant level must be maintained a level of the filler neck bottom (A).

*If the amount of the coolant is insufficient, fill the radiator up to the

bottom of the radiator filler neck (A) with the coolant, and install the cap turning it clockwise.

ACAUTION

For refilling, add the specified mixture of coolant and soft water. Adding water alone dilutes the coolant and degrades its anticorrosion properties. The diluted coolant can attack the aluminum engine parts. In an emergency, soft water can be added. But the diluted coolant must be returned to Vie correct mixture ratio within a few days.

H coolant must be added often, there is probably leakage in the

cooling system. Check the system for leaks (see Visual Leak

Inspection, and pressure Testing).

Coolant Draining

The coolant should be changed periodically to ensure long engine life.

ACAUTION

Use coolant containing corrosion inhibitors made specifically for aluminum engines and radiators in accordance with the instructions of the manufactures (see Coolant Filling Section).

Page 42

To avoid burns do not remove the radiator cap or try to change the coolant when the engine is still hot. Wait until it cools down. Since coolant is harmful to the human body, do not use for drinking.

ORemove the radiator cap (A) as follows. 0 First turn the cap counterclockwise to the first stop and wait there for

a few seconds.

OPush down the cap, then turn the cap counterclockwise to the next

stop.

0 Lift off the cap.

l Place a suitable container under the radiator. Turn the drain screw (B)

few turns counterclockwise to drain the coolant in the radiator.

COOLING SYSTEM 3-7

ORemove the muffler (see Muffler Removal).

@Remove one of the casecover mounting bolts (A) which attachs the

dipstick tube bracket (B) and casecover to the block together, and then take off the dipstick assembly.

@To drain the coolant in the engine, place a suitable chute under the

drain screws (black head) (C) located at the lowest water jacket of the

each cylinder to avoid a possible contamination of the starting motor (D) and igniter.

inspect the old coolant for color and smell (see Coolant Deterioration).

Coolant Filling

install the drain plugs. Always replace the gaskets with a new ones,

if they are damaged. @Tighten the drain screws to the specification (see Exploded Views). @Fill the radiator up to bottom of the radiator filler neck (A) with

coolant, and install the cap turning it clockwise.

NOTE

0 Pour in the coolant slowly so that it can expel the air from the engine

and radiator.

0 To install the radiator cap, push down it and then turn the cap

clockwise to the rest of the way.

Soft or distilled water must be used with the antifreeze in the cooling

If hard water is used in the system, it causes scales accumulation in

the water passages, and considerably reduces the efficiency of tie

II..

NOTE

OChoose a suitable mixture ratio by referring to the coolant

manufacture/s instructions.

Page 43

3-8 COOLING SYSTEM

Original Coolant

Type: Color:

Mixed ratio: Freezing Point:

Total amount:

Permanent type antifreeze for aluminum engine

and radiator

Green

50% solution of ethylene giycoi

-35°C (-31°F)

2.7L (0.7 U.S. gallon)

Air Bleeding

Before putting the engine into operation, any air trapped in the

cooling system must be removed as follows.

0 Remove the radiator cap. @Fill the radiator up to the radiator filler neck with coolant.

Check the cooling system for leaks.

install the radiator cap.

Start the engine, warm it up thoroughly, and then stop it.

Check the coolant level in the radiator after the engine cools down.

*If the coolant level is low, add coolant up to the filler neck bottom (A).

Install the cap.

Visual Leak Inspection

Any time the system slowly loses water, inspect for leaks. Small leaks may appear only a rust, corrosion or stain due to evaporation. Watch for these trouble spots.

Check the water pump housing drainage outlet passage (1) for coolant leaks.

*If the mechanical seal is damaged, the coolant leaks through the seal

and drain through the passage. Replace the mechanical seal (2).

*If there are no apparent leaks, pressure test the system.

Cooling System Pressure Testing

Air pressure leakage tester can help locate external leaks but they

cannot depended upon to locate small combustion leaks.

ACAUTION

During pressure testing, do not exceed the pressure for which the

system is designed. The maximum pressure is 102.7 kPa (14.9 psi).

ORemove the radiator cap, and install a cooling system pressure tester

(A) on the radiator filler neck.

Wet the cap sealing surfaces with water or coolant to prevent pressure

leaks.

@Build up pressure in the system carefully until the pressure reaches 60

kPa (8.7 psi).

Watch the pressure gauge for at least 6 seconds. If the pressure holds steady, the system is all right.

ORemove the pressure tester, replenish the coolant, and install the cap.

*If the pressure drops and no external source is found, check for internal

leaks. Droplets in the engine oil indicate internal leakage. Check the cylinder head gaskets.

Page 44

Flushing

Over a period of time, the cooling system accumulates rust, scale, and

lime in the water jacket and radiator. When this accumulation is

suspected or observed, flush the cooling system. If this accumulations

is not removed, it will clog up the water passage and considerably reduce

the efficiency of the cooling system.

0 Drain the cooling system. OFill the cooling system with fresh water mixed with a flushing

compound.

ACZAUTION

Avofd the use of a flushing compound which is harmful to Ule aluminum englne and radiator. Carefully follow the instructions supplied by the manufacturer of the cleaning product.

Warm up the engine, and run it at normal operating temperature for

about ten minutes.

Stop the engine, and drain the cooling system.

0 Fill the system with fresh water.

Warm up the engine and drain the system. 0 Repeat the previous two steps once more. @Fill the system with a permanent type coolant, and bleed the air from

the system.

COOLING SYSTEM 3-9

Disassembly and Assembly Precautions .

Prior to disassembly of cooling system parts (radiator, pump, sensor,

etc), wait until the coolant cools down, and then drain the coolant. @After assembling and filling the system with a coolant, purge any air

from the system.

Page 45

3-10 COOLING SYSTEM Water Pump

Water Pump Removal

0 Remove:

Muffler (see Muffler Assembly Removal)

0 Loosen the hose clamp (A) and disconnect the radiator hose (B) at

the coolant inlet port of of the water pump (C).

Loosen the tube clamp (D), and pull off the coolant by-pass tube (E).

@Unscrew the water pump mounting bolts, and remove the water pump

assembly.

NOTE

Note the position of different length of bolts so they can be installed in their original positions.

Installation Notes

@Chip the old gasket off the mating surfaces of the casecover and pump

housing.

Put a new gasket on the pump housing.

Be sure to suitable set the pump gear to be meshed with the cam gear

when installing the pump assembly.

position.

@Install the mounting bolts and tighten them to the specification (see

Torque Table).

0 Note the p.osition of different length of bolts.

Do not force the pump into

Boll Dimensions

A. Bolt M6 I = 75 mm (2.95 in)

B. Bolt M6 I = 65 mm (2.56 in)

C. Bolt M6 I = 70 mm (2.76 In)

D. Bolt M6 I = 45 mm (1.77 in)

Disassembly

For disassembly, follow the steps (A - J) below (see Illustration).

NOTE

Do not

unless they are to be replaced.

A. Plastic pump gear (1)

B. Dowel pin (2)

C. Claw washer (3)

D. Extract the impeller subassembly (12)(11)(10)(9)(8)(7) from the

E. Mechanical seal cartridge (6) F. Oil seal (4) G. Dowel pin (11)

H. Impeller (12)

I. Mating ring (7) and cup-gasket (8)

J. O-ring (10)

1. Pump Gear

2. Dowel Pin (1)

3. Claw Washer

4. Oil Seal

5. Drainage outlet passage 12. Impeller

6. Cartridge

7. Mating Ring

attempt

pump housing (13).

to remove the mechanical seal, oil seal and O-ring

8. Cup Gasket

9. Pump Shaft

10. O-Ring

11. Dowel Pin (2)

13. Pump Housing

Page 46

Internal Parts - Mechanlcal Seal

1. Mating Ring (Floating Seat)

2. Cup Gasket (Chusion Ring)

Seal Ring

4. Bellows

5. Spring Retainer

6. Coil Spring

Casing

8. Cartridge

Pump Parts Inspection

@Clean All parts except plastic and rubber parts in a bath of high

flash-point solvent and dry them compressed air. Clean non-metal parts with detergent and water, and dry them.

inspect the pump housing for damage. Mating surfaces should be

smooth and free of burrs and nicks. Replace the gasket if necessary.

Check the other parts for wear or damage, replace the parts if necessary.

*If the mechanical seal is damaged, the coolant leaks through the seal,

and drain through the drainage outlet passage.

*If the oil seal is damaged, the engine oil drain through the drainage

passage.

*If the mechanical seal parts are damaged, replace the seal as a set.

Visually check the impeller.

*lf the surface is corroded, or if the blades are damaged, replace all

internal pump parts.

COOLING SYSTEM 3-11

@Measure the outside diameter (B) of the impeller shaft (A) end with a

micrometer at several points.

*If the shaft end diameter is less than service limit, replace the shaft.

Outside Diameter of Impeller Shaft End

Service Limit: 9.935 mm (0.3911 in)

” ”

‘s‘.*i,;

.*1

‘,’ .I

..I ._

‘;; ,

- , .,:. ,

,.::““,z

,,,

I *\ ;,:,t

Assembly Notes

When installing the mating ring (1) into the cup gasket (Z), moisten

outside surface of the mating ring with fresh water and then push the

ring into the stop end. Do not damage mating surfaces.

OPack some amount of high temperature grease into the oil seal (3).

Press in the oil seal using a suitable tools so that the oil seal is flush

with the shoulder surface.

0 The oil seal must be assembled with spring loaded lip toward inside

of the engine.

NOTE

Page 47

3-12 COOLING SYSTEM

OWhen installing the impeller (4) sub assembly to the housing(5). coat

mating surfaces between the mating ring and seal ring (6) with a clean

water.

@To avoid oil seal damage, coat thin film of engine oil on the pump shaft

(7). and then carefully insert pump shaft into the housing.

Radiatdr

Removal

Always allow the engine to cool before removing the radiator cap. Then remove the cap slowly and carefully to avoid a possible fast

discharge of hot coolant which could cause severe burns.

ORemove the radiator cap and drain the coolant in the radiator (A) (see

Coolant Draining).

Loosen the hose clamps (B), and disconnect the radiator hoses (C)

at the coolant inlet and outlet of the radiator.

Unscrew the radiator mounting bolts (D), and remove the distance

collares (E).

Carefully remove the radiator with cooling air duct (F) to ivoid damaging the fan blades.

.’

Radiator Inspection

Check the radiator core.

*If the corrugated fins are deformed, carefully straighten them with the

blade of thin screw driver (A).

inspect the inlet and outlet tubes for cracks, kinks, dents, and fractured seams. Repair or replace the radiator, if necessary.

Check for dirt and insects that may be lodged in the radiator. them out by using compressed air or a low-pressure washer.

Using high-pressure water, as from a car wash facility, could damage the radiator fins and impair the radiator’s effectiveness.

ACAUTION

Clean

Page 48

lf the air passages of the radiator core are blocked more than 30% by unremoval obstructions or irreparably deformed fins, replace the radiator with a new one.

*If a radiator leak is detected, but cannot be spotted visually, test it as

follows:

1. Install the radiator cap, and plug the overflow tube (3) and inlet pipe (1). Attach an air hose (4) to the outlet connection (2).

2. Pressurize the inside of the radiator with compressed air to about 50

to 70 kpa (7 to 10 psi).

3. Submerge the radiator in water and look for bubbles (5) which indicate the location of the leak.

4. Repair any leaks or replace it with a new one.

CO.OLlNG SYSTEM 3-13

Check the radiator filler neck for signs of damage.

Check the condition of the top (A) and bottom (B) sealing seats in the filler neck. They must be smooth and clean for the radiator cap to function properly.

Radiator Cap inspection

The radiator cap has two functions:

1. Allow atmospheric pressure to enter the cooling system.

2. Prevents coolant escape at normal operating pressure. A pressure valve (D) in the cap permits the escape of coolant or steam

when the pressure in the system rises above the relief pressure.

A vacuum valve (E) in the cap opens when needed to prevent a

vacuum in the cooling system.

Check the condition of the valve spring (A), and the top (B) and bottom (C) valve seats of the radiator cap.

*If any one of them shows visible damage, replace the cap.

Wet the radiator cap (B) sealing surfaces with water or coolant to prevent pressure leaks.

install the cap on a cooling system pressure tester (A).

awatching the pressure gauge, pump the pressure tester to build up the

pressure. The cap must retain the pressure at least 6 seconds. Also the cap must open at the pressure shown in the table.

Radiator Cap Relief Pressure

Pressure Valve: 73.3 to 102.7 kPa (10.6 to 14.9 psi)

Vacuum Valve: 4.90 kPa (0.71 psi) (vacuum)

*If the cap cannot hold the specified pressure, or if it holds too much

pressure, replace it with a new one.

Page 49

3-14 COOLING SYSTEM

Radiator Hose Inspection

ln accordance with the Periodic Maintenance Chart, visually inspect the hoses (A) for signs of deterioration. Squeeze the hose. A hose should not be hard and brittle, nor should it be soft or swollen.

0 Replace any damaged hose.

NOTE

0 Hoses can deteriorated on the inside and still appear to be in good

condition on the outside.

Radiator Hose installation Notes

install the radiator hoses being careful to follow bending direction (see Exploded View). Avoid sharp bending, kinking, flatting, or twisting.

NOTE

OLocate the hose clamps (A) properly over fhe connections. A

pressurized cooling system will blow a hose that is not installed properly. Tighten the hose clamps securely.

Page 50

I---

_-.

-_‘-

Cooling Fan, Fan Belt

The only service on the cooling fan is to be sure the fan blades are not deformed, and the blade tips are far enough from the air duct to not strike the duct.

The fan belt should be neither too tight nor too loose.

Belt Tension Check

0 Remove:

Radiator (see Radiator Removal)

Measure the belt tension using a proper belt tension gauges (1). Follow the manufacturer’s instructions for use of the belt tension

gauge. The belt tension is adjusted between 25 kg (55 lb) and 40 kg

(88 lb) in the factory for the manufacturing standard.

*If the belt tension is less than specified limit, adjust or replace the belt

(2).

Bell Tenslon Service Limit

.18 kg (40 lb)

COOLING SYSTEM 3-15

*If the belt tension gauge is not available, push (3) the belt with a

thumb strongly at the middle between sheaves (l)(2). The slack (4) of the belt correspond the measurements of the belt tension gauge are as follow. Use the table as a guide line.

Belt Tension Measurements Slacks

25 kg (55 lb) -

40 kg (88 lb) - 9 mm (0.35 In)

18 kg (40

lb) -

12 mm (0.47 In)

17 mm (0.87 In)

Belt Replacement Notes

When replacing the fan belt, use only factory recommended belt with the proper length. To compensate for the belt length allowance, select

appropriately sized shim(s) (A) from the table to obtain proper level of the belt tension (25 - 40 kg).

Fan Belt

92180-2013’

of shim 92180-2014’

Part Number

t = Thickness of shim

t = 0.6 mm

t = 1.2mm

A Belt: Smaller allowance

D Belt: Bigger allowance

A B C D

1 2 1 2

1 1

NOTE

When tightening the sheave/hub (B) mounting nuts (C). rotate the

fan in either direction to avoid pinching the belt (0).

Drive Belt Specification

MITSUBOSHI - 59011-2058

Page 51

3-16 COOLING SYSTEM

Removal

0 Remove:

Radiator (see Radiator Removal) 0 Remove the radiator brackets (E). 0 Disconnect the wire tie (D) which binding the pressure switch, pulser

coil and primary ignition coil leads to the radiator bracket (E). 0 Disconnect the therm0 switch (A) lead and coolant bypass tube(B). ORemove the therm0 switch. 0 Unscrew the bracket mounting bolts (C) and nuts (F), then remove

the radiator mounting brackets.

OHold the fan drive sheave/hub (A) with a suitable spanner (D) to

prevent rotating the sheave/hub. @Unscrew the sheave/hub mounting nuts (B), and take off the

sheave/hub and shims (C). 0 Remove the fan belt rolling over the fan sheave.

NOTE

0 When removing the fan belt, note the belt so that it may be

reinstalled on the sheaves to rotate same direction as original installation.

Unscrew the mounting bolts (A), and take off the cooling fan (C) and

fan sheave (B).

Installation Notes

Install the cooling fan as “AISHIN” raised lettering (,

facing toward the radiator.

Clean the drive belt by wipping with a clean cloth

off any spilled oil or grease. Do not use solvent.

Install the belt on the sheave to rotate same direction as original

installation.

When tightening the sheave/hub mounting nuts, rotate the fan in

either direction to avoid pinching the belt.

Check the belt tension.

A) on the fan boss

immediately wipe

Inspection

Be sure the fan blades are straight. Deformed blades reduce the

cooiing system efficiency and throw the fan out of balance.

Check for excessive side wall wear of the sheaves and belt, replace if

necessary. The belt and sides of the sheaves should wear evenly.

*Check to be sure dirt has not lodged and packed in the sheave

V-grooves.

Check the belt for swells or lumps, replace if necessary.

Page 52

Fan Bearing Removal

0 Remove:

Fan Mounting Bracket (4)

Unscrew the fan shaft nut (1). and remove the shaft (3) and washer

(2).

To check the ball bearing (5), rotate the bearing slowly by finger; if any

roughness is noted, the bearing should be replaced.

Do not allow a flame or heating element to come in direct contact with the oil. Heat the oil in a well-ventilated area. Plan a safe handling procedure to avoid burns.

To remove the ball bearing, heat the bearing housing in a hot 150°C

(302°F) oil.

0 Use a heat shield gloves to prevent burns.

Place the bearing housing on a bench with bearing side up and take

off the bearing with a suitable tools.

COOLING SYSTEM 3-17

Do not remove the bearing unless it is necessary. Once it has been removed, it must be replaced.

ACAUTION

Fan Bearing fnsta llation Notes

Coat the bearing surfaces with a light film of engine oil.

Use a bearing driver, press in the fan side bearing flush with the housing (1).

install opposite side of bearing using a bearing driver until it stops at

the stop [spacer(2)] in hole.

install the fan shaft (6), washer (5) and nut (4), then tighten the nut

to the specified torque (see Exploded View).

1. Housing 4. Nut

2. Spacer

3. Circlip 6. Fan Shaft

5. Washer

Page 53

3-18 COOLING SYSTEM Thermostat

This cooling system is equipped with a thermostat to maintain a optimum operating temperature. stat when cold until operating temperature is attained,

Coolant bypasses the closed thermo-

Thermostat Removal

0 Remove

Radiator (see Radiator Removal) Cooling Fan (see Cooling Fan Removal) -

@Loosen the hose clamp (A) and disconnect the radiator hose (B) at

the thermostat cover.

Unscrew the thermostat cover bolts (C), and remove the cover.

Take off the thermostat (D).

NOTE

0 With the thermostat installed, the jiggle valve may be positioned

up-side of the thermostat when installing.

Thermostat Inspection

@Remove the thermostat, and check the jiggle valve (A) for sticking or

binding on the flange (8) due to accumulation of a rust, scale or lime. Clean up the valve to ensure free movement of the valve (C), if necessary.

inspect the thermostat valve (1) at room temperature.

*If the valve is open, replace the valve with a new one.

@To check valve openning temperature, suspend the thermostat and an

accurate thermometer (2) in a container filled with a water.

@Place the container over a source of heat and gradually raise the

temperature of the water while stirring the water gently.

Watch the valve. The valve should begin to open at the temperature

specified.

It should be fully opened to 7mm (0.28 in) or more at the temperature

specified.

Thermostat Valve Specification

Begin Opening 63 to 66 “C (145 to 150°F) Full Open 60°C (176°F)

The thermostat and thermometer must not touch the container sides.

*If the thermostat fails any of these check, replace it.

Page 54

Therm0 Switch

When coolant temperature rises above 111 “C (232’F), the therm0 switch detects this and turns on a warning light on dash. Whenever you start the engine, make sure the warning light is not on in started engine.

If the warning light comes on, stop the engine immediately, and check

the cooling system for over heating. Over heating can caused by:

Lack of coolant Loose or slipping fan belt

Clogging of cooling system

Malfunction water pump or thermostat

Check the coolant level and temperature frequently.

Therm0 Swtich Removal and Installation Notes

*Drain the coolant (see Coolant Draining).

Disconnect switch lead terminal (A).

0 Loosen the bypass tube clamp (C) and disconnect the tube (B).

Unscrew the therm0 switch and remove it.

When installing the therm0 switch (D), apply a non-permanent locking agent to the threads and tighten the switch to the specified torque (see Exploded View).

COOLING SYSTEM 3-19

therm0 Switch Inspection

Using a ohmmeter, check to see that only the connections in the table

have continuity.

*lf the switch has an open or short, repair it or replaced it \?rith a new

one. Therm0 Switch Connectlons

0 Rising temperature:

From Off to On at 108 - 114°C (226 - 237’F)

Falling temperature:

From On to FF at 101 - 107°C (214 - 226’F) ON: Continuity OFF: lnflnit

Suspend the switch (2) in a container of coolant (3) so that the

temperature sensing projection and threaded portion are submerged.

O-Suspend an accurate thermometer (1) in the coolant.

NOTE

0 The switch and thermometer must not touch the container sides or

bottom.

Place the container over a source of heat (4) and gradually raise the

temperature of the coolant while stirring the coolant gently.

Page 55

Engine Top End

ENGINE TOP END 4-l

Table of Contents

Exploded View Specifications Special Tools Cylinder Head..

Compression Cylinder

Installation Notes Push Rod Installation Notes Push Rod Inspection Disassembly and Assembly Cleaning

Va Ives ........................................................

Clearance Inspection

Clearance Adjustment.. Valve Seat Inspection..

Valve Seat Repair ..................................................................................................

Valve Head Thickness

Valve Stem Run Out

Valve Stem Diameter ........... .

Valve Guide Inside Diameter..

Valve Spring Inspection..

Cylinder, Piston .........................................................................................................

Piston Removal.. Piston Installation Notes

Piston/Cylinder Seizure.. ......................................................................................

Piston Cleaning Piston Ring and Ring Groove Wear.. Piston Ring End Gap.. Piston Pin, Piston Pin Hole, and Connecting Rod Wear Piston Diameter

Cylinder

Cylinder Boring and Honing

Muffler

....................................................................................................................... 4-23

Muffler Assembly Removal Muffler Assembly Installation Notes Inspection

............................................................................................................ 4-2

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

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

Measurement..

Assembly

Head

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

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

Inspection..

and

............................................................................................ 4-l 1

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

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

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

.................................................................................................... 4-20

Inside Diameter

............................................................................................................. 4-23

.................................................................................. 4-6

Removal ........................................................................

................................................................................... 4-8

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

....................................................................................... 4-9

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

......................................................................................... 4-l 1

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

........................................................................................... 4-l 5

................................................................................ 4-l 5

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

...................................................................................... 4-l 5

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

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

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

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

...................................................................................... 4-20

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

.................................................................................. 4-23

................................................................... .4-23

.......... ..4- 11

4-4

.4-5

4-6

.4-6 .4-7

.4-8

4-8

4-12 4-l 2

4-l 5

.4-l 5

4-l 6 4-16

..4-17

4-l 8

4-18 .4-l 8 .4-l 9

4-20

4-21

Page 56

4-2 ENGINE TOP END

Exoloded View

Tl: 8.8 N-m (0.9 kg-m, 78 in-lb) 12: 21.0 N-m (2.1 kg-m, 15 A-lb)

0: Apply engine oil G: Apply Grease

Page 57

ENGINE TOP END 4-3

ll: 21 N-m (2.1 kg-m, 15 tt-lb) L: Apply a non-permanent kxktng agent

to the threads.

Page 58

4-4 ENGINE TOP END

Soecifications

Item Service Limit

Cylinder Head:

Cylinder compression (M IN) Cylinder head warp 0.06 mm (0.002 in.)

Valves:

Valve seating surface width Valve head thickness Intake, Exhaust 0.6 mmm (0.024 in) Valve stem run out Intake, Exhaust Valve stem diameter Intake 5.945 mm (0.2341 in)

Valve guide inside diameter Intake 6.045 mm (0.2379 in) Valve spring free length Intake, Exhaust 29.70 mm (1 .I 7 in)

Rocker arm push rod runout Intake, Exhaust 0.80 mm (0.03 in) Rocker shaft outside diameter Intake, Exhaust 11.949 mm (0.4704 in) Rocker arm bearing inside diameter Intake, Exhaust 12.074 mm (0.4754 in)

Cylinder, Piston:

Piston ring/groove clearance Piston ring thickness

Piston ring end gap Top, Second

Piston pin outside diameter Piston pin hole inside diameter

Connecting rod small end inside diameter 17.051 mm (0.6713 in)

Cylinder inside diameter: Standard Cylinder 76.067 mm (2.9948 in)

Cylinder bore out of round

Intake, Exhaust

Exhaust 5.925 mm (0.2332 in) Exhaust 6.055 mm (0.2384 in)

Top

Second

Top, Second

Oil 1.5 mm (0.06 in)

0.25 mm Oversize 76.317 mm (3.0046 in)

0.50 mm Oversize 76.567 mm (3.0144 in)

0.75 mm Oversize

[1171 kpa (170 psi)] (MIN)

2.0 mm (0.08 in)

0.05mm (0.002 in)

0.15 mm (0.006 in)

0.12 mm (0.005 in) 1 .12 mm (0.044 in)

1.2 mm (0.05 in)

16.975 mm (0.6683 in)

17.041 mm (0.6709 in)

76.817 mm (3.0242 in)

0.056 mm (0.0022 in)

item Standard

Valve Clearance Intake, Exhaust Valve Seating Surface Angle Intake, Exhaust 45 Valve Seating Surface Width Intake, Exhaust 0.5 to 1 .l mm

Valve Guide Inside Diameter Intake, Exhaust 6.00 to 6.012 mm

Cylinder Bore Diameter

Standard cylinder 76.000 to 75.980 mm

0.25 mm Over size 76.250 to 76.230 mm

0.50 mm Over size 76.500 to 76.480 mm

0.75 mm Over size 76.750 to 76.730 mm

0.25 mm (0.01 in)

(0.02 to 0.043 in) (0.2362 to 0.2367 in)

(2.9921 to 2.9913 in)

(3.0020 to 3.0012 in) (3.0118 to 3.0110 in)

(3.0216 to 3.0209 in)

Page 59

Special Tools

Compression Gauge Assembly, Ml 4 x 1.25: 57001-I 23

ENGINE TOP END 4-5

Valve Seat Cutter Holder, @6: 57001-I 360

Piston Ring Pliers: 57001-I 15

Piston Ring Compressor Grip: 57001-I 095

Piston ding Compressor Belt, Q67 - @79: 57001-I 097

Valve Seat Cutter, 45” - @35: 57001-I 116

Valve Seat Cutter, 30” - @33: 57001-I 199

Valve Seat Cutter, 45” - @30: 57001-I 187

Valve Seat Cutter Holder Bar: 57001 -1128

Valve Seat Cutter, 30” - @30: 57001-I 120

Page 60

4-6 ENGINE TOP END

Cylinder Head Compression Measurement

l Before measuring compression, do the following. 0 Be sure the battery is fully charged. OThoroughly warm up the engine so that engine oil between the piston

and cylinder wall will help seal compression as it does during normal

running.

OStop the engine.

@Disconnect the spark plug caps of each cylinder and remove the spark

plugs.

@Attach the compression gauge assembly (A) (Special Tool:

57001-I 23) firmly into the one plug hole.

@Ground the spark plugs to the engine.

To avoid fire, do not ground the spark plugs in closed positions to the

plug holes. Keep the plugs as far away as possible from the plug holes.

@Using the starter motor, turn the engine over with the throttle fully

open until the compression gauge stops rising; the compression reading obtainable.

ORepeat the measurement to the other cylinder.

Cylinder Compression (MN)

1171 kPa (170 psi)

*If the compression is higher than the specified value, the piston rings,

cylinder and valves are probably in good condition.

*If the compression is too high, check the following.

(1) Carbon build-up on the piston head and cylinder head - clean off

any carbon on the piston head and cylinder head.

(2) Cylinder head gasket - use only the proper gasket. The use of a

gasket of incorrect thickness will change the compression.

(3) Valve guides and piston rings - rapid carbon accumulation in the

combustion chamber may be caused worn valve guides and/or worn piston oil rings. This may be indicated by white exhaust smoke.

* If cylinder compression is lower than the (MIN), check the following:

(1) Gas leakage around the cylinder head - replace the damaged

gasket and check the cylinder head warp. (2) Condition of the valve seating. (3) Valve clearance. (4) Piston/cylinder wear, piston seizure. (5) Piston ring, piston ring groove.

Cylinder Head Assembly Removal

0 Remove:

Radiator and it’s Bracket

Air Cleaner and Carburetor

Muffler Intake Manifold

Thermostat (No. 2 Cylinder)

Spark Plug

l Unscrew the rocker cover mounting bolts, and remove

gasket (o-ring). Do not lose the distance collars in the

A. Rocker Cover (No. 1 Cylinder)

B. Rocker Cover (No. 2 Cylinder) C. Mounting Bolts

D. Collars

! the cover

bolt holes.

and

Page 61

Loosen the cylinder head bolts l/4 turn in the sequence shown.

ENGINE TOP END 4-7

I-,

ACAlJllON

If the above procedure Is not followed, the cylinder head may be

warped during removal.

ORepeat the sequence until all bolts are removed and lift off the cylinder

head assembly.

NOTE

0 Mark the push-rods so they can be installed in their original position

during assembly.

0 Note the position of the special bolt (A) for reinstalling the cylinder

head.

(No.2 Cyl. shown)

Installation Notes

Clean the mating surfaces of the cylinder heads and cylinder.

install the push rods in their original positions on each cylinder. (see Push Rod Installation)

@Put a new gaskets and the cylinder head assemblies on each cylinder,

then let the cylinder heads with push rods aligned under the rocker arms.

NOTE

OAs the head gaskets are coated with sealing agents, be carefull not

to injure the surfaces of them.

install the head bolts noting the position of special bolts (A) and

tighten them temporarily.

(No.1 Cyl. shown)

install the intake minifold onto cylinder heads. (see Intake Manifold Installation Note)

Then tighten the head bolts to the specification (see Exploded View).

Follow the sequence shown, tighten the head bolts to 13 N-m (115 lb-in).

OTighten the bolts in sequence 3.0 N-m (27 lb-in) at a time until torque

on each bolt is 21 N-m (186 lb-in).

ACAUTION

A torque wrench must be used to prevent loose or overtight the head bolts which may result in warping of the cylinder head.

Page 62

4-8

ENGINE TOP END

Push Rod Installation Notes

@Align (RI ) mark on the flywheel (1) with (A) mark on the breather

chamber cover (2) turning the flywheel clockwise.

install the push rods in their original positions on each cylinder.

OTo install the push rod in a correct position on the tappet, insert the

push rod so end of the push rod is sliding down along inside wall of

the crankcase and position the push rod end on to the tappet.

Check both intake and exhaust push rods on each cylinder are lowest position on the cam lobes, if not turn the flywheel clockwise one turn

(360”) and align both marks on the flywheel and breather chamber

cover again.

0 Be sure the end of the push rods are correctly seated on the tappets.

1. Push Rods 4. Inside Walls

2. Tappets 5. Sliding Down

3. Lowest Cam Lobes

Push Rod Inspection

Place the rocker arm push rod in V blocks that are as far apart as

possible, and set a dial gauge on the rod at a point halfway ween between the blocks. Turn the rod to measure the runout. The difference between highest and the lowest dial readings is the amount of

runout.

*If the runout exceeds the service limit, replace the rod.

Rocker Arm Push Rod Runout

Service Limit:

0.8 mm (0.03 in)

Disassembly and Assembly

(Valve Mechanism Removal and Installation)

NOTE

0 When removing the valve mechanism parts, note the position of

them so that they may be reinstalled in their original position during assembly.

ORemove one of the rockershaft circlip (A) with a circlip pliers. 0 Remove the rocker armes (B) by pushing the rocker shaft (C) out the

side from which the circlip was removed.

Page 63

Support the valve head in the combustion chamber with a suitable block.

To remove the spring retainer (A), push down the retainer with thumbs

and shift (C) the retainer to a side hole (6) on the retainer.

0 Remove the spring and valve.

@Remove the stem seals (A) and bottom spring retainers (C).

NOTE

0 It is not necessary to remove the stem seal unless it is being replaced. 0 Bottom spring retainer can only be removed with stem seal. 0 Valve guide (B) is not replaceable, do no rernove it.

ENGINE TOP END 4-9

Valve Installation OApply engine oil to the valve stem to avoid damaging the stem seal. OCheck to see that the valve moves smoothly up and down in the guide. OCheck to see that the valve seats properly in the valve seat. If it does

not, repair the valve seat.

0 Rocker Arm Installation OApply engine oil to the bearing surface of rocker arm. OPut engine oil to the rocker arm where it touches the push rod and

valve stem end.

0 Install the rocker arm.

Cleaning and Inspection

@Scrape the carbon deposits from the head and exhaust port with a

suitable tool.

OTo avoid gouging, use scrapers that are made of a material that will

not cause damage.

@Clean the head in a bath of high flash-point solvent and dry it with

compressed air.

area, and take care that

there are no sparks or flame anywhere near the working area; this,

includes any appliance with a pilot light. Do not use gasoline or a low

flash-polnt solvent to clean the cylinder head. A fire or explosion

Lay a straightedge (A) across the gasket surface of the head at several different points, and measure warp by inserting a thickness gauge (6) between the straightedge and head.

+ If warp exceeds the service limit, repair the gasket surface. Replace the

cylinder head if the mating surface is badly damaged. Cylinder Head Warp

Service Limit: 0.06 mm (0.002 in)

Page 64

I - --

_..~----

4-10 ENGINE TOP END

Check the cylinder head for cracks or other damage.

Cracks not visible to the eye may be detected by coating the suspected

area with mixture of 25% kelosene and 75% light engine oil.

@Wipe the area dry and immediately apply a coating of zinc oxide

dissolved in wood alcohol. If a cracks is present, the coating will

become discolored at the defective area.

*If a cracks is present in the cylinder head, replace it.

inspect the gasket surface for burrs and nicks.

0 Inspect the cylinder head for accumulation of rust, scale and lime in the

water jacket (A).

*If this accumulation is observed, flush the cooling system (see

Flushing in Cooling System chapter).

*+*v~*>~ ,, “““I”i;“~

#Y “

@CA

OClean and measure the diameter of the rocker shaft (A) with a

micrometer at several points.

*If the outside diameter is less than the service limit, replace the shaft.

Rocker ShaH Outside Diameter

Servke Limit: 11.949 mm (0.4704 in)

Clean and inspect the rocker arm where it touches the push rod and

valve stem.

*If the contact points (A) are worn or damaged, replace the rocker arm.

0 Measure the inside diameter of the rocker arm bearing (B) at several

points using a dial bore gauge or inside micrometer.

*If the inside diameter is more than the service limit, replace the rocker

arm. Rocker Arm Bearing lnslde Diameter

Service Limit: 12.074 mm (0.4754 in)

Page 65

Valves

Clearance Inspection

NOTE

0 Valve clearance must be checked when the engine is cold (at room

temperature).

ORemove the rocker chamber cover (see Cylinder Head Removal).

Place the piston at top dead center (TDC) of the compression stroke

turning the crankshaft clockwise facing the flywheel. No. 1 Cylinder: OAlign (!,) mark on the flywheel (1) with (A) mark on the breather

chamber cover (2) as shown.

0 Check the intake and exhaust valves are closed completely, if not turn

the flywheel one turn (360”) clockwise and align both marks on the

flywheel and cover again. No. 2 Cylinder: OAlign ($ ) mark on the flywheel with (A) mark on the breather

chamber cover. Follow No. 1 Cylinder alignment procedure described

above. aThen check the clearance. 0 Using a thickness gauge (A), measure the valve clearance between the

rocker arm and the valve stem end.

*If the valve clearance is incorrect, adjust it.

Valve Clearance (when cold)

Intake, Exhaust: 0.25 mm (0.01 in)

ENGINE TOP END 4-11

Clearance AQustrnent

Since the valve repairs change the valve clearance, adjust the valve

clearance to the specification.

Assemble the cylinder head and install the cylinder head assembly on the block (see cylinder Head Installation Notes).

Turn the crankshaft proper direction until the piston is at TDC of the compression stroke (described above).

Loosen the locknut (C) and valve clearance adjusting screws( 6).

insert a 0.25 mm (0.01 in) thickness gauge (A) between the adjusting

screw and valve stem, and tighten the adjusting screw until the thickness gauge begin to bind between the rocker arm and valve stem end. Use a sweeping motion with the thickness gauge while making this adjustment.

Holding the adjusting screw with a spanner, tighten the locknut to the

specified torque (see Exploded View).

0 Do not overtighten.

Page 66

4-12 ENGINE TOP END

NOTE

OFor designing an adjustment tools, refer to the following

dimensional specifications.

1: 8.80 to 9.00 mm (0.346 to 0.354 in) 2: 3.85 to 4.25 mm (0.15 to 0.17 in) 3: 2.80 to 3.00 mm (0.11 to 0.12 in) 4: 2.00 to 2.50 mm (0.08 to 0.10 in) 5: M5 PO.5 screw 6: Rocker Arm

Valve Seat Inspection

0 Remove the valve. 0 Inspect the valve seats for damage.

*If the seats are warped or distorted by beyond reconditioning, replace

the cylinder head.

Pitted or worn the valve seats can be refaced. Lap the valves to the

seats after refacing.

@Coat the valve seat with machinist’s dye.

Push the valve into the guide. *Rotate the valve against the seat with a lapping tool. 0 Pull the valve out, and check the seating pattern on the valve head.

must be the correct width and even all the way around.

NOTE

The valve stem and guide must be in good condition or this check will not be valid.

*If the valve seating pattern is not correct, repair the seat.

Valve Seating Surface Width (STD)

Inlet, Exhaust:

0.5 - 1.1 mm (0.02 - 0.043 in)

Good Too Wide

Valve Seat Repair

Follow the manufacture’s instructions for use of valve seat cutters (special tools).

Use vlese Cutters

Intake Valve

Seat Cutter

Outslde Cutter

Exhaust Valve

Seat Cutter

Outslde Cutter

Use this Holder and Bar

Holder - 06.0 Bar 57001-1126

*If the manufacture’s instructions are not available, use the following

procedure.

Seat Cutter Operating Cares:

1. This valve seat cutter is designed only for valve seat repair. Therefore the cutter must not be used for other purposes.

45’ * Q35.0 30’ - a33.0

45” - Q30.0 57001-l 167

30” - Q30.0

57001-l 360

57001-1116 57001-1199

57001-l 120

Too Narrow

Uneven

Page 67

Do not drop or hit the valve seat cutter, or the diamond particles

2. may fall off.

3. Do not fail to apply engine oil to the valve seat cutter before grinding the seat surface. Also wash off ground particles sticking to the cutter with washing oil.

NOTE I

0 Do not use a wire brush to remove the metalparticles from the cutter.

It will take off the diamond particles.

4. Setting the valve seat cutter holder. in position, operate the cutter

with one hand. Do not apply too much force to the diamond portion.

NOTE

0 Prior to grinding, apply oil to the cutter, and during the operation

wash off any ground particles sticking to the cutter with washing oil.

ENGINE TOP END 4-13

1. Cutter

2. Cutter Holder

3. Bar After use wash the cutter with washing oil and apply a’thin layer of

5. engine oil before storing.

Marks Stamped on the Cutter:

The marks stamped on the back of the cutter represent the following.

1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cutter number, selected from 1 to 12

30” . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. .

37.5 . . . KS8B .

1. Cutter Outside Diameter

2. Cutter Angle

Operating Procedures:

Clean the seat area carefully.

@Recondition the valve seats with the valve seat cutters (45 ‘, 30 “) and

lap the valves.

Check the seats for good contact all the way around with machinist’s dye.

Measure the seat width is more than 2.0 mm (0.08 in) the seating

surface should be refaced.

*If the valve seating pattern is not correct, repair the seat.

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

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Manufactured lot number

. . . . . . . . . . . . . . . . Cutter angle

Outer diameter of cutter

Page 68

4-14 ENGINE TOP END

Coat the seat with machinist’s dye. OFit a 45 o cutter (A) to the holder and slide it into the valve guide. OResurface the valve seat with a 45 a cutter, removing only enough

material to produce a smooth and concentric seat.

ACAlJllON

Do not grind the seat too much. Overgrlndlng will reduce valve

clearance by slnklng the valve Into the head. H the valve sinks too far

Into the head, It will be lmposslble to adlust the clearance and the

cylinder head must be replaced.

Do not turn the cutter counterclockwlse or drop it against the seat, or it will be dulled.

Use a 30 ’ seat cutter (A) to narrow the seat width to the STD width.

OTurn the seat cutter one turn at a time while pressing down very lightly.

Check the seat width after each turn.

ACAUTION

The 30 ’ cutter removes material very qukkly. Check the seat wklth freauentlv to orevent over arlndlnp.

NOTE

Keep the seat width as closely as possible to 0.8 mm (0.03 in).

Make a light pass with the 45” cutter to remove any possible burrs at

the edge of the seat.

After resurfacing the seat, inspect for even valve seating.

OApply a machinist’s dye to the valve face, insert the valve, and snab it

closed against the seat several times. The valve surface should show good contact all the way around. on the valve face. The position of the valve in the seat is evident after

lapping the valve.

*If the seat does not make proper contact, lap the valve into seat with

a vacuum cap tool (A).

Coat the face of valve sparingly with a fine lapping compound.

Use the vacuum cup tool, to grip top of the valve. Rotate the valve in

a circular motion to lap the valve to the seat.

Lift the valve slightly from the seat every 8 to 10 strokes, continue lapping operation until a uniform ring appears around entire surface

of the valve face.

Be sure the valve seat is centered

@When lapping is completed, wash all parts in solvent to remove

lapping compound. Dry the parts thoroughly.

Note the position of the lapping mark on the valve face. The lapping mark should appear on or near the center of the valve face.

When the engine is assembled, be sure to adjust the valve clearances

(see Valve Clearance Adjustment).

Page 69

!-k-J /

! j

Valve Head Thickness

0 Remove the valve.

Measure the thickness of the valve head.

*if the valve head thickness (valve margin) (1) is less than the service

limit, replace the valve.

Valve Head Thkzkness

Service Limit (IN, EX): 0.6 mm (0.024 In)

Valve Stem Run Out

Support the valve in V blocks at each end of the stem.

Position a dial gauge perpendicular to the stem.

*Turn the valve and read the variation on the dial gauge.

*If the stem run out is greater than service limit, replace the valve.

Valve Stem Run Out

Service Limit (IN, EX): 0.05mm (0.002 in)

ENGINE TOP END 4-15

Valve Stem Diameter

Measure the diameter of the valve stem (A) in two directions at right angles, at four different positions on the stem.

*If any single measurement is less than the service limit; replace the

valve. Valve Stem Diameter

Servkx Limit

Intake: 5.945 mm (0.2341 in)

Exhaust: 5.925 mm (0.2332 in)

Valve Guide Inside Diameter

Use a small bore gauge or a micrometer to measure the inside diameter

of the valve guide a three places down the length of the guide.

*If the measurement is more than the service limit, replace the cylinder

head with a new one.

Valve Gukte Inside Diameter

Sarvka Limit

Intake: 6.045 mm (0.2379 In) Exhaust:

6.055 mm (0.2384 in)

Valve Spring Inspection

inspect the valve spring for pitting, cracks, rusting, and burrs. Replace

the spring if necessary.

Measure the free length of the spring.

*If the measurement is less than the service limit, replace the spring.

Valve Spring Free Len@h

Servkx Llmlt 29.70 mm (1.17 in)

Page 70

4-16 ENGINE TOP END

Cylinder, Pistorn

Piston Removal

OSplit the crankcase (see Camshatft/Crankshaft chapter).

0 Remove the camshiaft (see Camshaft/Crankshaft chapter). @Turn the crankshaft to expose the connecting rod cap bolts. ORemove the bolts and take off the connecting rod caps.

A. Cap Bolts

B. Caps

Push the connectilng irod end into the cylinder. end pull the piston and connecting rod out of the cylinder.

r -

Note a localion ol the, arrow malch mark on the piston head In relation to MADE IN JAPAN on the connecting rod. No. 1 cyl. piston is opposlle of No. 2 cyl. piston. Keep parts together as a set.

1. Arrow Match Marks 3. Large Chamfers

2. Flywheel Side 4. Raised Letters

C. Pry Points

ACAUTlON

(MADE IN JAPAN)

-1

---J

. . .

@Remove one of the piston pin snap rings with needle nose pliers.

A. Piston Pin Snap Rings

B. Pliers

@Remove the piston by pushing the piston pin out the side from which

the snap ring was; removed.

A. Piston Pin

ORemove the top and second rings with a piston ring pliers (special tool:

57001-l 15). If tha special tool is not available, carefully spread the ring opening with your thumbs and then push up on the opposite side of the ring to remove it.

ORemove the 3-piece oil

A. Piston Ring Pliers

ring

with your thumbs in the same manner.

Page 71

Piston Installation Notes

*Oil Ring Installation: OFirst install the expander in the piston oil ring groove so that the

explander ends butt together.

0 Install the upper and lower steel rails. There is no UP or Down to the

rails. They can be installed either way.

A. Expander ends

l install the chrome-plated top ring and second ring with “N” mark

facing up. The rings should turn freely in the grooves.

@Align the piston and rings with the piston ring end gap as shown.

1. Arrow Mlatch Mark

2. Top Ring End Gap, Upper Side Rail End Gap

3. 45”

4. Second Ring End Gap, Lower Side Rail End Gap

ENGINE TOP END 4-17

Apply engine oil to the piston pins.

*Assemble the pistons onto the connecting rods as follow:

No. 1 Cyl. piston, align the arrow match mark on the piston head with

the raised letters (MADE IN JAPAN) on the connecting rod.

No. 2 Cyl. piston, align the arrow match mark on the piston head with

opposite MADE IN JAPAN on the connecting rod. A. No. 1 Cyl. Piston

6. No. 2 Cyl. Piston E. Opposite MADE IN JAPAN

C. Arrow Match Marks

l When in.stalling a piston pin snap ring, compress it ortly enough to

install it and no more.

OFit a new piston pin snap1 ring into the scde of the piston so that the

ring opening (A) does not coincide with the notch (B) in the edge of the piston pin hole.

reuse snap rings, as removal weakens and deforms

ouf and score the cylinder wall.

@Apply engine oil to the piston skirt and the cylinder bore. 0 Using the piston ring comlpressor grip (special tool: 57001-l 095) and

the belt (special tool: 570’01 -1097). insert the piston and connecting rod into the cylinder.

0 Insert the piston and connecting rod so that the arrow match mark on

the top of the piston facing the flywheel side.

A. Arrow Match Mark

B. Flywheel Side

No. 1. Cylinder Shown

D. MADE IN JAPAN

Page 72

4-18 ENGINE TOP END

Piston/Cylinder Seizure

l In case of seizure, remove the piston.

Visually inspect the cylinder and piston damage.

*If there is only light damage, srnooth the piston with #400 emery cloth.

Remove the small aluminum deposits from the cylinder with #400 emery cloth or light honing.

*If the damage is severe, the both cylinders must be bored oversize and

an oversized pistons installed.

Piston Cleaning

ORemove the piston (and pistonrings (see Piston and Ring Removal).

-Never clean lhe piston head with the engine assembled. partkles will fall between ths piston and cyllinder, and damage the crankshaft bearlngs.

Scrape the carbon off (A) the piston head.

aUse the scraping tools carefully. Do not gouge the piston head. To

avoid gouging, use scrapers .that are made of a material that will not cause damage.

l C:lean the piston ring grooves (A) with a broken piston ring or other

suitable tools.

Be careful not 80 widen the rlng grooves.

require plston replacement.

PCAUTION

Daimaged rlng grooves will

Piston Ring and Ring Groove Wear

0 Clean the piston (see Piston Cleaning).

Visually inspect the piston rings and ring groloves.

*If the piston rings are worn unevenly or damaged, replace them.

*If the ring grooves are worn unevenly or damaged, replace both the

piston and piston rings.

*Check ring grooves for wear by inserting a new ring in the proper

groove at several points around the piston.

*Measure the clearance between the top anfd second rings and their

grooves using a thickness gauge (A).

Page 73

*If the piston ring/groove clearance is greater than the specified value,

replace the piston. Piston Ring/Groove Clesrance

Servke Limit

Top Second

0.15 mm (0.005 in)

0.12 mm (0.005 in)

NOTE

The oil ring is a three piece assembled ring.

ring groove clearance and thickness, visually inspect only.

Difficult to measure the

l Measure the piston ring thickness.

o Use a micrometer to measure at several points around the rings. *If any of the measurement are less than the service limit, replaoe the

entire set of rings.

Piston Ring Thickness

Service Llmit

Top Secand

1.12 mm (0.W in)

1.12 mm (0.044 in)

NOTE

0 When using new rings in a used piston, check for uneven groove

wear. The rings should fit perfectly parallel to the groove sides. If not, replace the piston.

ENGINE TOP END 4-19

Piston Ring End Gap

0 Remove the piston rings. @Push each ring (one at a time) in the cylinder bore 1.1

the bottom of the cylinder bore. 0 Use the piston to push it in to be sure it is square. l Measure the gap between the ends of the ring (A)

ww @I.

*If the end gap of any Iring is greater than the service

entire set of rings.

Piston Ring End Gap

Sewvice Llmit Top, Second Oil

1.2 mm (0.05 In)

‘I .5 mm (0.05 in)

3 a point close to

with a thickness

limit, replace the

Page 74

4-20 ENGINE TOP END

i”

J-I

Piston Pin, Piston Pih Hole, and

Connecting Rod Wear

@Remove the piston pin.

Measure the diameter of the piston pin with a micrometer at several points.

*If the outside diameter is less than service limit, replace the piston pin.

Piston Pln Outslde Diameter

Servke Llml: 16.975 mm (0.6682 In)

Measure the inside diameter of the piston pin hole at several points on both side. Use a dial bore gauge.

*If the inside diameter is more than the service limit, replace the piston.

Piston Pin Hole lnslde Diameter

Service Llmlt: 17.041 mm (O-.6709 In)

0 Measure the inside diameter (A) aof the small end of the connecting rod

at several points. Use a dial bore gauge.

*If the inside diameter is more than the service limit, replace the

connecting rod. Connecting Rod Small End lnrlde Diameter

Servke Llmlt: 17.051 mm (0.6713 In)

Piston Diameter

*Measure the outside diameter of the piston 11 mm (0.43 in) up from

the bottom of the piston at a right angle to the direction of the piston

pin hole.

*If the measurement is fess than the service limit, replace the piston.

PbtonDhmobr

Senke Llrnlt 75.875 mm (2.9672 In)

Cylinder Inside Diameter

Clean and measure the cylinder inside diameter.

0 Use a dial bore gauge to measure front-to-back and side-to-side at the

points shown below.

*If any of the cylinder bore measurements is greater than the service

limit* the cylinder must be bored to the next oversize and then honed

(see Cylinder Boring and Honing).

Cyllndar lnslde Diameter

standard: Swvke LImIti

76.000 mm (2.9921 in)

76.067 mm (2.9948 ln)

/ -

i’

lOllIll

55lml

1 omn-

-~-

. . .”

Page 75

0.25 mm Oversize: 76.25ll mm (3.0020 in) Service Limit: 76.317 mm (3.0046 in)

ENGINE TOP END 4-21

0.5 mm Oversize: Service Limit:

0.75 mm Oversize: Servke Limit

Cylinder Bore Out-of-Round

Standard: 0.01 mm (0.0004 in) Servke Limit: 0.056 mm (0.0022 in)

76.500 mm (3.0118 in)

76.567 mm (3.0144 In)

76.750 mm (3.0217 in)

76.817 mm (3.0242 in)

Cylinder Boring and Honing

Always resize to exactly ‘0.25 mm (0.01 in), or 0.5 mm (0.02 in), 0 75

mm (0.03 in) over the standard bore size.

If this is done accurately, the stock oversize rings and pistons will fit

perfectly and Iproper clearance will be maintained.

Resizin’g the cylinder balre can be done by reliable repair shop or by

using a drill press and honilng tool.

Use the stone recommended by the hone manufacturers to produce

correct cylinder wail finish.

Machine-bore first, the bore diameters should be shown in the table. Change to a honing stone for finishing, the final bore diameter should

be as shown tin the table.

Be sure the correct stone is used and the stone is not worn.

@Clean the cylinder at the top and bottom of the cylinder to remove

burrs and pieces of the base and head gasket.

Anchor the cylider (block) on the drill press table before honing.

@Align the center of the cylinder bore to the press center. Set the press

to operate from 200 to 250 rpm.

@Connect the drive shaft to the hone and set the stop on the drill press

so the hone can only extend 20 to 25 mm (3/4 to 1 .O in) above the top or below the bottom of the cylinder liner.

ORotate the adjusting nut (knob) on the hone until the stones conltact

snugly against the cylinder wall at the narrowest point. “Do not

Force.”

@Turn the stone by hand. If you cannot turn it, the stone is too tight.

Loosen the hone until it can be turned by hand.

@Be sure that the cylinder and hone are centered and aligned with the

drive shaft and drill spindle.

Pour honing oil inside aof the cylinder during the honing operation. Start the drill press. Mlove the hone up and down in the cylinder

approximately 20 cyclesper-minute.

Check the diameter of the cylinder bore regularly during honing, using an inside micrometer.

-Stop the drill press before measuring and remove the hme from the cylinder.

-- 3

AQWTION

Fine Boring Bore Dlameter

Bore Diameter

76.230 to 76.210 mm (3.0012 to 3.0004 in)

76.480 to 76.460 mm (3.0110 to 3.0102 in)

0.50 mm 76.730 to 76.710 mm

Final Bore Diameter

1 Oversize 1 Bore Diameter

0.25 mm 76.250 to 76.230 mm

I 0.5omm

0.50 mm

(3.0209 to 3.0201 in)

(3.0020 to 3.0012 in)

76.500 to 76.480 mm (3.0118 to 3.0110 in)

76.750 to 76.730 mm (3.0216 to 3.0209 in)

NOTE

0 The .finish should not be smooth, but have a 40 to 60 degree

crosshatch pattern.

OHone the cylinder until it is about 0.007 to 0.009 mm (0.0003 to

0.0004 in) large to allow for shrinkage when the cylinder cools.

Page 76

4-22 ENGINE TOP END

NOTE

Do not use gasoline. kerosene. or commercial solvent to clean the cylinder bore. These fluids only wash all r’he oil from the cylinder wall. They do not remov(e the metal pa.rticles produced during

honing.

Clean the cylinder thoroughly. Use soap warm water and clean rags. Clean the cylinder wall for “white glove” inspection. A clean white rag

should not show soil from the cylinder wall.

Dry the cylinder and coat with a engine oil.

The cylinder must be thoroughly cleaned after honlng IO eliminate all grit.

AKAUllON

Page 77

Muffler

ENGINE TOP END 4-23

.-.

^.S

Muffler Assembly Remo wal

l Unscrew the exhaust pipe mounting nuts, and remove the spring

washes and engine hook (B) [No. 2 Cylinder(C)]. Use a penetrating oil if necessary to breaking threads.

ORemove the bolts on the muffler bracket and take off the muffler

assembly.

0 Do not use unnecessary force on the exhaust pipes when removing thle

muffler assembly, or they could become damaged or distored.

Muffler Assembly lnstalhtion Notes

@Clean the exhaust pipe flanges to the exhaust port gasket surfaces and

install a new gaskets each time the muffler installed.

Apply a non-permanent locking agent to the threads of the exhaust pipe mounting nuts.,

l To prevent mis-threading, finger tight the bolts (A) and nuts first. Next

tighten the nuts, then the bracket (B) mounting bolts.

@After installation, thoroughly warm up the engine, wait unti the engine

cools down and retighten the bolts and nuts.

Inspection

inspect the exhaust pipes or muffler for dents, cracks, rust and holes.

*If the exhaust pipes or muffler is damaged, it should be replaced for

best performance and leasit noise.

*Check the muffler for distortion and/or loose internal components.

Loss of power could develop if the muffler loose the intern.al

components restricting the exhaust flow.

*Check for breaks in the seams and check weld at the junction of the

exhaust pipes antl muffler.

Tap the muffier with a plastic hammer to decarbonize.

Page 78

[-I1

LUBRICATION SYSTEM 5-l

Lubrication System

Table of Contents

E.xploded View ...........................................................................................................

Engine Oil Flow Chart.. Specifications

Engine Oil and Oil Filter.. .........................................................................................

Oil Level inspection Oil Change

Oil Filter Removal Oil Filter Installation Notes..

Pressurized L.ubrication

Oil Pressure Measurement Oil Pressure Switch Inspection

, I..,

Oil Pump and Relief Valve

Removal Installation Notes Inspection..

Oil Screen Filter .........................................................................................................

Removal. ...............................................................................................................

ktstallation Notes.. Cleaning and Inspection..

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

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

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

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

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

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

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

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

System

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

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

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

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

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

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

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

.5-2

5-3 5-4

.5-5

5-5

.5-6

5-6

5-7

,5-8

5-8 5-8 5-9 5-9 5-9

5-9 5-12 5-12 5-‘12 5-12

_,,.-.

Page 79

5-2 LUBRICATION SYSTEM

Exploded View

l-l: 15.0 N-m (1.5 kg-m, 11.0 Mb)

T2: 23.0 N-m (2.3 kg-m, 16.5 R-lb)

0: Apply engine oil G: Apply grease L: Apply a non-pewmanent locking agent

to lhe lhreads.

Page 80

Engine Oil Flow Chart

LUBRICATION SYSTEM 5-3

r-._

K-T----

Page 81

5-4 LUBRICATION SYSTEM

SDecif ications

---.

Engine Oil:

Grade Viscosity

Capacity

Level

Oil Pressure (MIN)

Oil Pressure Switch:

Detect pressure

Screw

Gil Filter By-pass Valve Openning

Pressure

--I

Oil Pump:

Inner and outer rotor clearance Outer rotor outside diameter Outer rotor thickness

Pump housing inside diameter

Pump housing depth

Pump shaft outside diameter

Relief valve spring free length

Pump shaft bearing inside diameter

Item

Standard

API Service Classification ; SC, SD, SE, SF, !sG, or SH

SAE40, SAE30, SAEl OW-30 / SAEl OW-40, or

SAE5W-20 (see Oil Change)

1.8L (3.80 US pt) [When filter is not removed:]

1.5L (3.17 US pt) [When filter is removed] Between upper and Lower level line 276 kPa (40 psi)

98 kPa (14.2 psi)

PT l/8 pipe thread

78.5 to 117.5 kPa (11.4 to 17.1 psi)

Service Limit

0.3 mm (0.012 in)

40.470 mm (1.5933 in)

9.830 mm (0.387 in)

40.801 mm (1.606 in)

10.230 mm (0.4028 in)

10.923 mm (0.4300 in) 1950 mm (0.77 in)

11.072 mm (0.4359 in)

Page 82

Engine Oil and Oil Filter

LUBRICATION SYSTEM 5-5

Engine operation with InsuHklent, deteriorated, or contaminated engine oil WIN cause accelerated wear and may result in engine seizure and accident.

Oil Level lnspec~ion l

Place the engine on a level surface and check the oil level.

Clean area arourrd the dipstick (A) before removing it.

@Remove the dipstick and wipe it with a clean cloth.

insert the dipstick into tube (6) following the tube bend and let it’s plug firmly fit into the tube, then check the oil level.

The oil level should be between the “H” and “L” marks on the dipstick.

*If the oil level is near or below the “L” mark, remove the oil filler cap

l-------

Do not fill above the “t-t” mark. Excess oil will cause a smoking

condition, and may cause the engine to overheat.

ACAUTION

*If the oil Level is too high, remove the excess oil by loosening the drain

plug (W.

ACAUTION

Before starting the engine for the first time, add oil: The engine. Is

Preoil the engine to force all air from the internal oil

OFill fresh engine oil to the specified level. 0 Run the engine at slow speed 2 minutes.

Stop the engine and check the oil level.

Add oil only to the “H” mark on the dipstick. Use the same type and make of oil that is already in the engine.

NOTE

Olf the engine oil type and make are unknown, use any brand of the

specified oil to top up the level in preference to runntng the engine

with the oil level low. Then at your earliest convinience, change the oil completely.

Page 83

5-6 LUBRICATION SYSTEM

Oil Change

Change oil after first 210 hours of operation. Thereafter change oil every 100 hours.

@Check that there is oil in the crankcase.

Start and warm up the engine so the oil will drain easily. Stop the

engine. 0 Place the engine on a level surface. @Tilt the engine and place a suitable container under the engine. ORemove the drain plug (A), and let the oil drain completely.

Be careful with not oli being drrrined. it may be not enoqh to bum

youM”eraly.

*Check the gasket (6) at the drain plug for damage. Replace the gasket

with a new one if it is damaged.

emstall the drain plug with the gasket and tighten it to the specified

torque (see Exploded View).

ORemove the oil filler cap and refill the engine with a high quality oil of

recommended viscosity in the chart.

Use a good quality SD, SE or SF class oil. Chose the viscosity 01 oil

Check the oil level (see Oil Level Check).

NOTE

OSoms increase in oil consump8tion may be expected when a multi

grade engine oil is used. Check the oil level frequently.

Engine Oil cbpacity

Capacity: 1.8 L (3.80 U.S. PI)

[When filter ISI not removed]

1.5 L (3.17 U.S. PI) [When fiiter b removed]

Engine Oil Level

Between upper and lower level line

Oil Filter Removal

Using a strap wmnch (S), remove the oil filter.

0 When unscrewing the toil filter (A), place a suitable container beneath

the oil drip tray (C) to receive oil lfrom the oil filter and 011 passages in the engine. Turn the filter counterclockwise to remove it.

Ambient Temperature ---

-MY -10°C o’c 1 o”c 2o”c 30% 4.0°c

-4’F 14’F 32’F 5O*F 68*F 86’F 104’F

Page 84

Oil Fitter Installation Notes

*Apply a thin coat of grease ‘to the seal (A). 0 Install a new fiiltelr. OTurn the filter until the setal contacts mounting surface (6) of the

engine. Then turn the filter BY HAND(S) 3/4 turn more.

aRun the engine at slow idle speed 2 minutes. Check for leaks around

the engine.

Stop the engine. Check the oil level (see Oil Level Check). Add oil

only to the “H” mark on the dipstick.

LUBRICATION SYSTEM 5-7

Page 85

5-8 LUBRlCATlON SYSTEM

Pressurized Lubrication System

The engine lubrication circuit is a pressurized system consisting of a positive displacement pump which picks up oil through a filter screen from the crankcase. The oil is pumped to a replaceable oil filter cartridge, through the engine’s oil passages lo lubricate internal components, and return to the crankcase. A bypass valve is incorporated in the oil filter to allow oil to circulate if the filter becomes clogged. A pressure relief valve

is used between the oil pump and oil filter to relieve excessive oil pressure by returning excess oil to the crankcase (see Oil Flow Chart).

Oil Pressure Measurement

l Remove the oil pressure switch (A) from the crankcase. @Install an appropriately sized oil pressure gauge adapter and

pressure gauge. l Run the engine ‘and allow warrn l Run the engine ,at fast idle speed and read the oil pressure gauge.

Stop the engine. 0 Remove the oil pressure gauge and adapter. *Apply a non-permanent locking agent to the taper threads of

pressure switch and install the switch. *If the oil pressure is below the specification, inspect the oil pump

relief valve. *If the oil pump and relief valve are not at fault, inspect the rest of the

lubrication system.

completely.

oil

the

and

Oil Pressure (Ylnlmum)

276 kPa (40 psi)

011 Pressure Swlkh

PT 118 (Taper Pipe Threads)

Oil Pressure Switch Inspection

When the oil pressure falls below 98 kPa (14.2 psi), the oil pressure

switch activates the oil warning lamp to alert the operator or lubricating

problem.

*To check the oil warning system, insert the switch key into the “OFF”

position of the engine switch, the’n turn it to the “RUN” position. The warning light must be illuminated.

@Whenever start the engine, make sure the warning light is not on in

started engine.

*If the warning light comes on, stop the engine immediately and check

the oil level.

When starting the engine, note the warning light on dash carefully.

*If the warning light is on in the started engine in spite of adequate oil

level, check the laad from the pressure switch to the warning light for short circuit and/or check the pressure switch and replace damaged part.

*If the light is not on al: the moment of the engine switch operation,

check all leads of the warning light circuit or bulb and replace damaged parts.

Page 86

Oil Pump and Relief Valve

Removal

Split the crankcase (see Camshaft/Crankshaft chapter).

*Unscrew the mounting screws and take off the oil pump parts

assembly (pump gear, pump cover plate, pump shaft, pins and rotors).

@Take off the relief valve spring and ball.

Disassemble the ,pump par& assembly

1. Pins 6. Pump Shaft

2. Pump Gear

3. Mounting Bolts 8. Spring

4. Outer Rotor 9. Pump Cover Plate

5. Inner Rotor

Installation Notes

OFill the rotNor housing with engine oil for initial lubrication. @Install the relief valve ball and spring in position, then install the pump

parts assembly in the crankcase cover.

0 When Installing the pump parts assembly, align the 6mm DIA hole

(A) on the cover plate with center of the relief valve.

install the mounting bolts and tighten them securely.

7. Relief Valve Ball

10.6mm DIA Hole

NOTE

LUBRICATION SYSTEM 5-9

^I...

Jnspection

0 Remove the oil pump. @Visually inspect the pump gear, outer and inner rotor, and cover plate.

*If there is any damage or ulneven wear, replace them.

OCheck the clearance (A) between the inner and outer rotor with a

feeler gauge. Measure the clearance between the high point of the inner rotor and the high point of the outer rotor.

*If the measurement exceed the service limit, replace the rotors as a set.

Inner and Outer Rotor Clearance

Senlca Limk 03mm (O.Ol2 in)

Measure the outside diameter (A) of the outer rotor with a micrometer

at several points.

*If the rotor diameter is less than the service limit, replace both the inner

and outer rotor.

Outer

Rotor Dlametar

&rvka Llmll: 49A70 mm (1.9933 In)

@Measure the thickness (5) of the outer rotor with a micrometer *at

several points.

*If the rotor thickness is less than the service limit, replace both the inner

and outer rotor.

Outer Rotor Thkkness

Service Llmltz

9.920 mm (0.2970 In)

Page 87

5-10 LUBRICATION SYSTEM

Measure the inside diameter (A) of the pump housing with a inside micrometer at several points.

*If the inside diameter is more than the service limit, replace the

crankcase cover. Pump Housing Inside Diameter

Service Limit: 40..901 mm (1.9093 in)

0 Measure the depth (6) of the puimp housing with a depth micrometer

at several points.

*If any of measurement is more than the service limrt, replace the

crankcase cover.

Pump HousIng Depth

Sanka Limit: 10.290 mm (0.4028 in)

Measure the outside (A) diameter of the pump shaft with a micrometer

at several points.

*If the diameter is less than the service limit, replace the pump shaft.

Pump ShafI Diameter

Sewke Llmk 10.923 mm (0.4300 in)

Measure the inside diameter (A) of the pump shaft bearing in the

crankcase cover with a inside micrometer at several points.

*if the inside diameter is more than the service limit replace the

crankcase cover. Inside Diametar of Pump Shaft Bearlng

Servke Limit: 11.072 mm (0.4359 In)

Visually inspect the relief valve spring, steel ball and valve seat in the crankcase cover.

*If any rough spots are found during above inspection, wash the valve

clean with a high flash-point solvent and blow out any foreign particles that may be in the valve with compressed air.

Clean the pats tn a rell ventilated areas and take care lhat there k

no spa& or flame anywhere near the wotidng areas. Becawe ot the dangar of hlghiy flammabbk Ilquids, do not we gasoline or low nash-polnl solvents.

Page 88

*If cleaning does not solve the problem, replace the relief valve parts. *If necessary, put the ball in position and lightly tap the ball with ;a

suitable tools to form a perfect seat.

Measure free length (A) of the spring with a vernier

Cdiper.

It If the free length of the spring is less than the service limit, replace the

spring.

Free Len@h d Spring

Senke Limit: 19.90 mlm (0.77 in)

LUBRICATION SYSTEM 5-11

Page 89

5-12 LUBRICATION SYSTEM Oil Screen Filter

Removal

Spiite the crankcase and remove the crankcase cover (see Camshaft/Crankcase chapter).

*Unscrew the mounting screws (A) and remove the filter chamber

cover (B) with oil induction pipe..

Pick up the filter screen.

installation Notes

Clean the oil filter screen (A) thoroughly whenever it is removed for any reason.

Insert the screen in position and install the chamber cover.

install the screws and tighten them securely.

Cleaning and Inspection

clean the oil screen with high flash-point solvent and remove any particles stuck to it.

Clean the screen in a well-ventilated area, and take care that there

b no spark or Hame anywhere near the working area. Because ot the danger d highly tlammable liquids, do not use gasoline or low

flash+oint solvents.

NOTE

0 While cleaning the screen, check for any metal particles that might

indicate internal engine damage.

Check the screen carefully for any damage: holes and broken wire.

*If the screen is damaged, replace it.

Page 90

CAMSHAFT/CRANKSHAFT 6-l

Camshaft/Crankshaft

Table of Contents

Exploded View

Specifications ..............................................................................................................

Crankcase

Splitting.. ................................................................................................................

Assembly..

Inspection.. .............................................................................................................

Journal Bushing Replacement..

For Designing Bushing

Breather

Removal .................................................................................................................

Installation Notes ...................................................................................................

Inspection

Camshaft Tappet

Removal .................................................................................................................

Installation

Inspection.. .............................................................................................................

Camshaft

Crankshaft, Connecting Rod

Connecting Rod Removal Connecting Rod Installation Notes Crankshaft Removal/Installation Notes

Cleaning/Inspection Connecting Rod Bend/Twist Connecting Rod Big Connecting Crankshaft Runout.. Crankshaft Crankpin Resizing

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

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

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

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

Tools.. ..............................................................................

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

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

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

Notes.. .................................................................................................

Bearing/Journal Wear.. .........................................................................

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

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

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

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

End/Crankpin Width Wear..

Rod Big End Bearing/Crankpin

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

Main Journal/Wear..

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

.I.. ..............................................................

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

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

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

Wear.. ...........................................

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

.6-2

6-3

6-4 ,6-4 .6-4 .6-5 .6-6 .6-7

6-8 .6-8 .6-8

6-8 .6-9 .6-9 .6-9 .6-9 .6-9

.6-11

6-11 6-l 1

.6-l 1

6-12

6-12 .6-12 .6-13 .6-13

..6-14

.6-14

Page 91

6-2 CAMSHAFT/CRANKSHAFT

Exdoded View

ll: 21.0 N-m (2.1 kg-m, 15 Mb) T2: 21 .O N-m (2.1 kg+n, 15 Mb)

0: Apply OngIno 011 G: Apply gnaao

Page 92

CAMSHAFT/CRANKSHAFT 6-3

j L,

Item

Camshaft, Tappet:

Cam lobe height

Camshaft journal diameter Camshaft bearing inside diameter

Crankshaft, Connecting Rod:

Connecting rod bend Connecting rod twist Connecting rod big end width

Crankpin width

Connecting. rod big end inside dia. Crankpin outside diameter

Crankshaft runout Crankshaft journal diameter

Crankcase:

PTO shaft bearing inside diameter

Water pump shaft bearing inside dia.

Crankshaft journal bearing Inside dia.

Service Limit

Intake 25.21 mm (0.993 in) Exhaust 25.46 mm (1.002 in) PTO side 15.907 mm (0.6263 in) Flywheel side 15.917 mm (0.6267 in) Crankcase 16.066 mm (0.6326 in) Crankcase cover 16.068 mm (0.6326 in)

0.15/l 00 mm (0.006/3.94 in)

21.20 mm (0.83 in)

44.5 mm (1.75 in)

34.055 mm (13407 in)

33.927 mm (1.3357 in)

0.05 mm (0.002) TIR PTO side 33.909 mm (1.3350 in) Flywheel side 33.909 mm (1.3350 in)

Crankcase cover 34666 mm (1.3412 in)

10.088 mm (0.3972 in)

Crankcase 34.114 mm (1.3431 in)

Page 93

6-4 CAMSHAFT/CRANKSHAFT

Crankcase

Splilthg

Set the engine on a clean surface while parts are being removed.

0 Remove (see appropriate chapter).

Muffler Assembly Air Cleaner Assembly Carburetor Assembly Throttle Control panel

Radiator

Radiator Hoses and Bypass Tube Water pump Assembly Cooling Fan and Brackets Cylinder Head Assemblies

Intake Manifold

Flywheel Stator coil

Pulser coils

Ignition coils

Igniter

Starter Motor

Igniter and Bracket

Oil Drip Tray

Oil Filter

Unscrew the mounting bolts in the order shown and pull the crankcase cover from the crankcase.

OThere are two knock pins on the crankcase mating surface. A wooden

or plastic mallet may be used to gently tap loose the crankcase cover.

Assembly

Before fitting the cover onto the crankcase, note the following.

OChip-the old gasket off the mating surfaces of the crankcase and cover,

and clean off the crankcase, crankshaft and other internal components. After cleaning apply engine oil to any rubbing surface of these components.

0 Be sure to replace any oil seal removed with a new one. The oil seal

must be assembled with spring (1) loaded lip toward inside of the engine.

OPack some amount of a high temperature grease (5) into the space

between the seal lip (2) and dust lip (3). Press in the new oil seal using a press or suitable tools until it is flush with flange surface (4).

Do not damage the seal lips.

Page 94

OCheck that the governor weights are closed. 0 Be sure to suitably set the governor gear to be meshed with the cam

gear and the oil pump gear to be meshed with the crank gear when installing crankcase cover. position. Gear train: viewed from PTO skle

0 Note the position ot dltterent length ot the bolts. Olnstall the crankcase cover and tlghten the case cover bolts to the

spscffled toque (see Exploded Vlew) In the sequence as shown. Do not turn one screw down completely before the others, as It may cause a warped the crankcsse cover.

Do not force the crankcase cover into

CAMSHAFT/CRANKSHAFT 6-5

Inspection

Clean up the crankcase and cover with a high flush-point solvent, and blow out any foreign particles that may be in the pockets inside of the crankcase with compressed

Clean the crankcase and cover In a well-ventllated area, and take care that there lq no spark or flame anywhere near the work@ area. Because d the danger of highly flammable Ilqukts, do not use gasoline or low flush-point solvents.

inspect the crankcase for accumulation of rust, scale and lime in the

water jacket.

*If this accumulation is observed, flush the cooling system (see

Flushing in Cooling System chapter).

inspect the crankcase for coolant leakage out side water jacket.

leaks may appear only as rust, corrosion or stains, due to evaporation.

Gaskets: Tighten a parts or install a new gasket. Use a sealing

compound when required.

Bolts: Apply sealing compound when required.

inspect the crankcase for coolant leakage into the engine.

A. Water Jacket C. Push Rod Compartment B. Gasket Surfaces

A coolant leaks into the engine through:

A loose cylinder head A cracked or porous casting

The push rod compartment

@Give special attention to the cylinder head gasket.

*If coolant leaks from the gasket surfaces:

OCheck the gasket surfaces for burn and traces of the gas leakage,

replace the gasket if necessary.

OCheck the cylinder head and block surfaces are clean, level and

smooth. (see Engine Top End chapter)

OCheck the cylinder head for correct installation (see Engine Top End

chapter).

air.

Small

Page 95

6-6 CAMSHAFT/CRANKSHAFT

A cracked or porous casting are not visible to eve, an evidence of leakage of the coolant from suspected area are found, replace the crankcase (block).

*If a coolant leakage from the push rod compartment is appeared

replace the crankcase (block).

Measure the inside diameter (A) of the PTO shaft bearing on the crankcase cover at several points. This bearing is not replaceable.

Replace the crankcase cover if the inside diameter is more than the

service limit. PTO Shall SearIng Inslde Diameter

Service Limit 24.066 mm(l.2412 In.)

Measure the inside diameter (A) of the water pump shaft bearing on

the crankcase at several points. This bearing is not replaceable.

Replace the crankcase cover if the inside diameter is more than the

service limit. W&w Pump Shafl

Servke Limit 10.088 mm (0.2972 in.)

Measure the inside diameter (A) of the crankshaft journal bearing on the crankcase at several points. Replace the journal Bushing if the inside diameter is more than the service limit.

Cranksbafl Journal Searlng Inside Dbmeter

Servke LitnIt 24.114 mm (1.2421 in.)

Bearing

Inside Diameter

Journal Bushing Replacement

The journal bushing (2) is press fit into the crankcase (1).

ORemove the oil seal on the crankcase.

The oil seal should not be reused once removed.

Place the crankcase on a support block (4) with the oil seal side up.

Using a bushing tool (a), drive out the bushing as shown.

Page 96

The service bushing is to be reinstalled using a bushing tool as shown.

Coat the bushing and flange surface with light film of oil, press in the new bushing flush with the flange surface.

No finish reaming is required.

1. Flange Surface

2. New Bushing 4. Support Block

3. Bushing Tool

for Designing Bushing Tools

1. Bushing Inside Diameter (MIN)

33.997 mm (1.3385 in.)

2. Housing Inside Diameter (MIN)

38.000 mm (1.4961 in.)

3. Bushing Width

26.0 mm (1.02 in.)

4. Bushing Counter Sunk 1 .O mm (0.04 in.)

CAMSHAFT/CRANKSHAFT 6-7

Page 97

6-8 CAMSHAFT/CRANKSHAFT

Breather

The function of the breather is to create a vacuum in the crankcase

which prevent oil from being forced out of the engine through the piston

rings, oil seals or gaskets. The breather has a reed valve (C), which limits the direction of air flow caused by the piston moving up and down. Air can flow out of the crankcase,but the one way reed valve blocks return flow. It thus maintains a vacuum in the crankcase.

Oil laden air in the crankcase passes through the reed valve and expand into the breather chamber. Here most oil separates from the air and drains back to the crankcase. The air passes through a maze (E) and vents to the air cleaner (F).

Removal

ORemove the breather chamber cover.

Unscrew the mounting screw (A), and remove the back plate (B) and reed valve.

Installation Notes

Be sure the drain back hole (D) does not accumulate with slugges

before installing the breather valve.

@Align center of the valve seat with center of the reed valve and back

plate, then tighten the mounting screw.

NOTE

0 The mounting screw is a self-tapping one.

misthreading or overtightening screw will strip the female threads and ruin the hole.

Be aware that

Inspection

inspect the reed valve for breakage, hair cracks or distortion, replace it if necessary.

inspect the

if necessary.

inspect the valve seating surface. The surface should be free of nicks

or burrs.

back

plate for damage or rough contact surface, replace it

Page 98

Camshaft Tappet

Removal

split the crankcase (see Crankcase Splitting).

Turn the crankcase up side down so that the tappets will fall away from the cam lobes.

Pull the camshaft out of the crankcase.

NOTE

0 Before removing, align the punch mark (A) on the crankgear with

the projection (B) on the camgear.

ORemove the tappets and mark them so they can be installed in their

original positions during assembly.

Installation Notes

Apply engine oil to the following.

Tappet Journal

Camshaft Journal Cam Lobe Surface Cam shaft Gear

OAlign the punch mark on the crankgear with the projection on the

camgear.

CAMSHAFT/CRANKSHAFT 6-9

b D

Inspection

Check the camshaft gear (A) for pitting, fatigue cracks, burrs or an

evidence of improper tooth contact.

Check the top of the cam lobes (B) for wear, burrs or uneven contact. Replace the shaft if necessary.

Replace the shaft if necessary.

Camshaft Bearing/Journal Wear

Measure the height of each cam lobe.

*If the cam height is less than the service limit for either lobe, replace the

camshaft. Cam Lobe Helght

Servke Limit: IN. 25.2l mm (0.993 in.)

EX. 25.46 mm (1.002 in.)

With a micrometer, measure both camshaft journals at several points around the journal circumference.

*If the journal diameter is less than the service limit, replace the

camshaft. PTO Side Journal Dlameter

Senfke Limit: 15.907 mm (0.6263 in.)

Flywheel Side Journal Diameter

Servke Limit: 15.917 mm (0.6267 in.)

Page 99

6-10 CAMSHAFT/CRANKSHAFT

Measure the inside diameter of the camshaft bearing (A) on the crankcase at several points. This bearing is not replaceable. Replace the crankcase if the inside diameter more than the service limit.

Camshatt Bearing Inside Dlameter

Service Llmlt: 16.066 mm (0.6326 in.)

Measure the inside diameter of the can crankcase cover at several points.

This bearing is not replacable. Replace

inside diameter is more than the service limit.

Camshatt Bearing Inside Diameter

Servke Limit: 16.068 mm (0.6326 In.)

ishaft bearing (A) on the

the crankcase cover if the

Page 100

Crankshaft, Connecting Rod

Crankshaft, Connecting Rod Removal/Installation:

Connecting Rod Removal

ORemove the connecting Rod during the piston removal (see Piston

Removal in the Engine

Connecting Rod Installation Notes

See Piston Installation Notes in the Engine Top End chapter for assembling the piston onto the connecting rod and insert the assembly into the cylinder.

Turn the crankshaft until the crankpin is lowest position.

Apply engine oil tothe bearing portion of each connecting rod big end and cap.

install each connecting rod big end onto the crankpin.

Place the connecting rod caps over the crankpin so the pilot grooves (B) on the caps and rods are aligned.

Be sure the large chamfers on the connecting rods facing toward each

crank web.

Coat a light film of oil on the threads of connecting cap bolts (A).

install cap bolts and tighten them to the specified torque (see Exploded View)

TOD

End chapter).

CAMSHAFT/CRANKSHAFT 6-11

Crankshaft Removai/lnstallation Notes

0 Remove

Flywheel Camshaft Connecting rod and piston assembly

*Pull the crankshaft out of the crankcase. Tap gently with a wooden

or plastic mallet if necessary to loosen the crankshaft.

Clean up the crankshaft and crankcase thoroughly, especially at the bearing contact surfaces.

Pack some amount of high temperature grease into the oil seal on the

crankcase.

Apply engine oil to the journal and bearing.

Carefully insert the crankshaft flywheel end into the main bearing and oil seal in the crankcase, if necessary, cover the key way on the crankshaft taper with a tape to avoid damaging these parts.

Be sure to fit the woodruff key correctly on the crankshaft taper.

A. Woodruff Key

B. Crankshaft Taper

C. Oil Seal

Toro 73545, 73546, 73547, 73580 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual