Toro 22163, 22164, 22164TE, 22175, 22176 Service Manual

4-stroke air-cooled gasoline engine

Quick Reference Guide

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General Information 1

Periodic Maintenance 2

Fuel System 3

Cooling System 4

Engine Top End 5

Lubrication System 6

Camshaft/Crankshaft 7

Electrical System 8

This quick reference guide will assist
you in locating a desired topic or pro­cedure.

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 con-

•

tents for the exact pages to locate
the specific topic required.

Troubleshooting 9

FJ180V

4-stroke air-cooled gasoline engine

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 & Machinery
Company/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 i t 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.

© 2002 Kawasaki Heavy Industries, Ltd. First Edition (1) : Nov. 20, 2002 (K)

LIST OF ABBREVIATIONS

A ampere(s) lb pound(s)

ABDC after bottom dead center m meter(s)

AC alternating current min minute(s)

ATDC after top dead center N newton(s)

BBDC before bottom dead center Pa pascal(s)

BDC bottom dead center PS horsepower

BTDC before top dead center psi pound(s) per square inch

C

DC direct current rpm revolution(s) per minute

F farad(s) TDC top dead center

F

ft foot, feet V volt(s)

g gram(s) W watt(s)

h hour(s) ohm(s)

L liter(s)

degree(s) Celsius r revolution

degree(s) Fahrenheit TIR total indicator reading

Read OWNER’S MANUAL before operating.

EMISSION CONTROL INFORMATION

To protect the environment in which we all live, Kawasaki has incorporated crankcase emission
(1) and exhaust emission (2) control systems (EM) in compliance with applicable regulations of
the United States Environmental Protection Agency and California Air Resources Board.

1. Crankcase Emission Control System

A sealed-type crankcase emission control system is used to eliminate blow-by gases. The
blow-by gases are led to the breather chamber through the crankcase. Then, it is led to the
air cleaner.

Oil is separated from the gases while passing through the inside of the breather chamber

from the crankcase, and then returned back to the bottom of crankcase.

2. Exhaust Emission Control System
The exhaust emission control system applied to this engine consists of a carburetor and

an ignition system having optimum ignition timing characteristics.

The carburetor has been calibrated to provide lean air/fuel mixture characteristics and op-

timum fuel economy with a suitable air cleaner and exhaust system.

TAMPERING WITH EMISSION CONTROL SYSTEM PROHIBITED

Federal law and California State law prohibits the following acts or the causing thereof: (1) the
removal or rendering inoperative by any person other than for purposes of maintenance, repair,
or replacement, of any device or element of design incorporated into any new engine for the
purpose of emission control prior to its sale or delivery to the ultimate purchaser or while it is in
use, or (2) the use of the engine after such device or element of design has been removed or
rendered inoperative by any person.

Among those acts presumed to constitute tampering are the acts listed below:
Do not tamper with the original emission related part:

Carburetor and internal parts

•

Spark plug

•

Magneto or electronic ignition system

•

Fuel filter element

•

Air cleaner elements

•

Crankcase

•

Cylinder head

•

Breather chamber and internal parts

•

Intake pipe and tube

•

Foreword

This manual is designed primarily for use by
trained m echanics 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 tools, and workshop proce­dures must be understood in order to carry out
maintenance and repair satisfactorily. When­ever the owner has insufficient experience or
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

•

maintenance.

Use proper tools and genuine Kaw asaki en-

•

gine parts. Genuine parts provided as spare

parts are listed in the Parts Catalog.

Follow the procedures in this manual care-

•

fully. Don’t take shortcuts.

Remember to keep complete records of main-

•

tenance and repair with dates and any new

parts installed.

How to Use This Manual

In this manual, the product is divided into
its major systems and these systems make up
the manual’s chapters. 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.

For example, if you want ignition coil informa­tion, use the Quick Reference Guide to locate

the Electrical System chapter. Then, use the
Table of Contents on the first page of the chap­ter to find the Ignition coil section.

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

WARNING

This warning symbol identifies special

instructions or procedures which, if not

correctly followed, could result in per-

sonal injury, or loss of life.

CAUTION

This caution symbol identifies special

instructions or procedures which, if not

strictly observed, could result in dam-

age to or destruction of equipment.

This manual contains four more symbols (in
addition to WARNING and CAUTION) which will
help you distinguish different types of informa­tion.

NOTE

This note symbol indicates points of par-

ticular interest for more efficient and con-

venient operation.

Indicates a procedural step or work to be

•

done.

Indicates a procedural sub-step or how to do

the work of the procedural step it follows. It

also precedes the text of a WARNING, CAU-

TION, or NOTE.

Indicates a conditional step or what action to

take based on the results of the test or inspec-

tion in the procedural step or sub-step it fol-

lows.

In most chapters an exploded view illustration
of the system components follows the Table of
Contents. In these illustrations you will find the
instructions indicating which parts require spec­ified tightening torque, oil, grease or a locking
agent during assembly.

GENERAL INFORMATION 1-1

General Information

TABLE OF CONTENTS

Before Servicing ........................................................................................................................ 1- 2

Model Identification.................................................................................................................... 1- 4

General Specifications............................................................................................................... 1- 5

Torque and Locking Agent......................................................................................................... 1-6

1

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. For the same reason, before
installing a new part, clean off any dust or metal filings.

(2) 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, t he bolts, nuts, or screws
must be tightened in the order and method indicated.

(3) 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.

(4) 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, t ap 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.

(5) Edges

Watch for sharp edges, especially during m ajor engine disassembly and assembly. Protect your
hands with gloves or a piece of thick cloth when lifting the engine or turning it over.

(6) High-Flash Point Solvent

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

(7) Gasket, O-Ring

Do not reuse a gasket or O-ring once it has been in service. The mating surfaces around the
gasket should be free of foreign matter and perfectly smooth to avoid oil or compression leaks.

(8) 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.

(9) Oil Seal and 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.

(10)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.

(11)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

GENERAL INFORMATION 1-3

Before Servicing

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 m akes reference to molybdenum disulfide grease (MoS2) in the assembly of certain
engine parts. Always check manufacturer recommendations before using such special lubricants.

(12)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.

(13)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.

(14)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 Hardening Warp
Bent Dent Scratch Wear
Color change Deterioration Seizure

(15)Specifications

Specification terms 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.

1-4 GENERAL INFORMATION

Model Identification

GENERAL INFORMATION 1-5

General Specifications

Items FJ180V

Type of engine Forced air-cooled, vertical shaft, OHV, 4-stroke gasoline engine

Bore x Stroke 65 mm x 54 mm (2.56 in x 2.13 in)

Piston displacement 179 mL (10.9 cu. in)

Direction of rotation Counterclockwise facing the PTO shaft

Compression release Automatic compression release

High idle speed 3200 rpm

Ignition system Flywheel magneto with CDI

RFI Per Canada and U.S.A. requirements

Starting system Recoil starter

Spark plug NGK BPR5ES

Carburetor Float type, fixed main jet

Air cleaner Dual stage element, dry type

Governor Flyweight all speed governor

Lubrication system Pressure feed by positive displacement pump

Oil capacity
(when engine is
completely dry)

Cooling system Forced air cooling by fan

Dimensions (L x W x H ) 390 mm x 307 mm x 284mm (15.4 in x 12.1 in x 11.2 in)

Dry weight 15.0 kg (33.3 lb)

Specifications subject to change without notice.

0.65 L (0.69 US-qt)

1-6 GENERAL INFORMATION

Torque and Locking Agent

The following tables list the tightening torque for the major f asteners, 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.

O : Apply an oil to the threads, seated surface, or washer.

S : Tighten the fasteners following the specified sequence.

SS : Apply silicone sealant.

Fastener

N·m

Fuel System:

Throttle Valve Screw 0.7 0.07 6in·lb
Main Jet 1.1 0.11 9.7 in·lb
Governor Arm Clamp Nut 7.8 0.80 69 in·lb
Priming Nut 1.2 0.12 11 in·lb
Fuel Tank Cover Bolts 6.9 0.70 61 in·lb
Tank Drain Bolt 6.9 0.70 61 in·lb
Float Chamber Mounting Bolt 5.4 0.55 48 in·lb
Drain Screw 4.2 0.43 37 in·lb

Cooling System:

Flywheel Bolt 42 4.3 31

Engine Top End:

Cylinder Head Bolts 22 2.2 16 =S
Valve Clearance Lock Screws 6.9 0.70 61 in·lb
Connecting Rod Big End 5.9 0.60 52 in·lb =O

Cap Bolts
Rocker Arm Bolts 28 2.8 20
Rocker Cover Mounting Bolts 5.9 0.60 52 in·lb
Spark Plug 22 2.2 16
Muffler Cover Self Tap Bolt (1) 6.9 0.70 61 in·lb

Lubrication System:

Oil Drain Plug 22 2.2 16 in·lb
Oil Filter Cover Bolt 6.9 0.70 61 in·lb

Camshaft/Crankshaft:

Crankcase Cover Bolts 8.8 0.90 78 in·lb =S

Electrical System:

Flywheel Bolt 42 4.3 31
Recoil Starter Mounting Bolts 6.9 0.70 61 in·lb
Recoil Starter Set Screw 1.0 0.10 8.9 in·lb
Spark Plug 22 2.2 16
Brake Lever Assembly Mounting Bolt 6.9 0.70 61 in·lb
Kill Switch Bolt 1.5 0.15 13 in·lb

Brake Arm Mounting Bolt 9.3 0.95 82 in·lb

Torque

Remarks

kgf·m ft·lb

GENERAL INFORMATION 1-7

Torque and Locking Agent

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.

Basic Torque for General Fasteners

Threads dia Torque

(mm) N·m kgf·m ft·lb

4 2.0 0.20 17 in·lb
5 3.4 0.35 30 in·lb
6 5.9 0.60 52 in·lb

8 15 1.5 11

PERIODIC MAINTENANCE 2 -1

Periodic Maintenance

TABLE OF CONTENTS

Periodic Maintenance Chart ...................................................................................................... 2-2

Specifications ............................................................................................................................ 2- 3

Special Tools ............................................................................................................................. 2- 4

Periodic Maintenance Procedures............................................................................................. 2- 5

Fuel System............................................................................................................................ 2- 5

High Idle Speed Adjustment ................................................................................................ 2- 5

Fuel System Cleanliness Inspection .................................................................................... 2- 5

Fuel Filter Inspection............................................................................................................2-6

Air Element Removal ........................................................................................................... 2- 6

Air Element Installation ........................................................................................................ 2-7

Air Element Cleaning and Inspection................................................................................... 2- 7

Air Cleaner Housing (Case and Body) Inspection ............................................................... 2- 8

Engine Top End ...................................................................................................................... 2- 8

Cylinder Head Cleaning and Inspection............................................................................... 2- 8

Valve Clearance Inspection ................................................................................................. 2- 8

Valve Clearance Adjustment ................................................................................................ 2- 9

Valve Seat Inspection .......................................................................................................... 2- 9

Valve Seat Repair ................................................................................................................ 2-10

Lubrication System ................................................................................................................. 2-13

Oil Level Inspection..............................................................................................................2-13

Oil Change ........................................................................................................................... 2-13

Electrical System .................................................................................................................... 2-14

Spark Plug Cleaning and Inspection.................................................................................... 2-14

Spark Plug Gap Inspection .................................................................................................. 2-14

2

2-2 PERIODIC MAINTENANCE

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 (
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.

) designates that the corresponding item

•

•

INTERVAL

Every
50 hr.

100 hr.

•

Every

•

•

Every

200 hr.

•

OPERATION

Daily

Check or clean air intake screen
Check and add engine oil
Check for fuel and oil leakage

Check for loose or lost nuts and
screws
Clean air cleaner foam element (1)

Clean air cleaner paper element (1)
Tighten nuts and screws
Change engine oil
Clean and re-gap spark plug

Change air cleaner paper element
(1)

Clean dust and dirt from cylinder
and cylinder head fins (1)

Check and adjust valve clearance

Clean and lap valve seating surface

Clean combustion chamber

(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.

First 8

hr.

•

•

•

•

Every
25 hr.

• •

Every

300 hr.

•

•

•

•

PERIODIC MAINTENANCE 2 -3

Specifications

Item Standard

Fuel System

High idle speed 3200 r/min (rpm)

Air cleaner:

Type Dual stage filtration system
Pre-cleaner Foam element
Second-stage cleaner Paper element

Engine Top End

Valve clearance Intake Exhaust 0.10 ~ 0.15 mm (0.004 ~ 0.006 in.)
Valve seating surface angle Intake Exhaust
Valve seating surface width Intake Exhaust 0.6 ~ 0.9 mm (0.024 ~ 0.035 in.)

Lubrication System

Engine oil:

Type SF, SG, SH or SJ class
Viscosity SAE30, SAE10W-30
Capacity [When engine is completely dry]

Level Operating range (grid area) on dipstick

45

0.65 L (0.69 US-qt)

Electrical System

Spark plug gap 0.75 mm (0.030 in.)

2-4 PERIODIC MAINTENANCE

Special Tools

Valve Seat Cutter, 45 - f27.5: 57001–1114

Valve Seat Cutter, 32 - f25.0: 57001–1118

Valve Seat Cutter, 32 - f28.0: 57001–1119

Valve Seat Cutter Holder Bar: 57001–1128

Valve Seat Cutter Holder - f6.0: 57001–1360

Periodic Maintenance Procedures

Fuel System

High Idle Speed Adjustment

CAUTION

Do not adjust high idle speed with the air cleaner
removed.

Start and warm up the engine throughly.

•

WARNING

Always keep your hands clear of the moving parts.

Move the throttle lever at a dash to the high idle position.

•

Loosen the control panel mounting bolts [A] enough to

•

move the control panel assembly.
Carefully move the control panel assembly right or left to

•

obtain the specified high idle speed.

PERIODIC MAINTENANCE 2 -5

High Idle Speed

3200 rpm

Tighten the Mounting bolts.

•

Fuel System Cleanliness Inspection

WARNING

Gasoline is extremely flammable and can be ex­plosive under certain conditions. Turn the engine
switch stop position. 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.

Remove the primer pipe from the tube.

•

Place a suitable container [B] under the drain screw [A]

•

on the carburetor.
Loosen the drain screw to drain the carburetor and check

•

to see if water or dirt has accumulated in the carburetor.
Tighten the drain screw.

•

Torque - Drain Screw: 4.2 N·m (0.43 kgf·m, 37 in·lb)

Install the primer pipe in the tube (see Fuel System chap-

•

ter).
If any water or dirt is found, clean the carburetor and fuel

•

tank (see Fuel System chapter).

2-6 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Fuel Filter Inspection

Visually insect the fuel filter [A].

•

If the filter is clear with no signs of dirt or other contami-

nation, it is OK and need not be replaced.

If the filter is dark or looks dirty, replace with a new one.

Also check the rest of the fuel system for contamination.

Check the O-ring at the tank drain for damage. Replace

•

the O-ring with a new one if it is damaged.

Air Element Removal

Move the holders [A].

•

Push up the latches [A] and remove the air cleaner case

•

[B].

Remove:

•

Paper Element [A]

Foam Element [B]

Periodic Maintenance Procedures

Air Element Installation

Install:

•

Foam Element
Paper Element

Install the hollow [A] of the air cleaner case and projection

•

[B] of the air cleaner body are fitting.

Move the holders [A].

•

PERIODIC MAINTENANCE 2 -7

Air Element Cleaning and Inspection

NOTE

In dusty areas, the elements should be cleaned more
frequently than the recommended intervals.

WARNING

Because of the danger of highly flammable liquids,
do not use gasoline or a low flash-point solvent to
clean the element.

Remove the paper element and the foam element.

•

Clean the foam element [A] in a bath of detergent and wa-

•

ter, and let the element air-dry throughly before installing
it.

Clean the paper element [A] by tapping it gently on a flat

•

surface to remove dust. If the element is very dirty, re­place it with a new one.

CAUTION

Do not use compressed air to clean the paper ele­ment. Do not oil the paper or foam element.

2-8 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Air Cleaner Housing (Case and Body) Inspection

Clean the housing with detergent and water and dry thor-

•

oughly.

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 obstructing the air pas-

•

sage.

Engine Top End

Cylinder Head Cleaning and Inspection

Remove the cylinder head (see Engine Top End chapter).

•

Scrape the carbon deposits from the head and exhaust

•

port with a suitable tool [A].

To avoid gouging, use scrapers that are made of a m ate-

•

rial that w ill not cause damage.

Clean the head in a bath of high flash-point solvent and

•

dry it with com pressed air.

WARNING

Clean the cylinder head in a well-ventilated area,

and take care that there are no sparks or flame any-

where near the working area, this includes any ap-

pliance with a pilot light. Do not use gasoline or a

low flash-point solvent to clean the cylinder head.

A fire or explosion could result.

Straight edge [A] across the mating surface of the head at

•

several different points, and measure warp by inserting a

thickness gauge [B] between the straightedge and head.

If warp exceeds the service limit, repair the mating sur-

face. Replace the cylinder head if the mating surface is

badly damaged.

Cylinder Head Warp

Service Limit: 0.03 mm (0.001 in.)

Check the cylinder head for cracks or other damage.

•

Cracks not visible to the eye may be detached by using

•

a metal crack detection system (Visual color check: com-

monly found at automotive parts tore.).

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

•

Inspect the mating surface for burrs and nicks.

•

Valve Clearance Inspection

NOTE

Valve clearance must be checked when the engine is
cold (at room temperature).

Remove the rocker cover (see Engine Top End chapter).

•

Place the piston at top dead center (TDC) of the compres-

•

sion stroke turning the crankshaft rotational direction.

Periodic Maintenance Procedures

Then check the valve clearance.

•

Using a thickness gauge [A], measure the valve clearance
beween the rocker arm [B] and the valve stem end.
If the valve clearance is incorrect, adjust it.

Valve Clearance (when cold)

Intake, Exhaust

Valve Clearance Ad justment

Since 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 Engine Top End chapter).
Turn the crankshaft to the proper direction until the piston

•

is at TDC of the compression stroke (described above).
Loosen the lock screws [A] and valve clearance adjusting

•

nuts [B].
Insert a 0.10 mm (0.004 in.) thickness gauge [C] between

•

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

0.10 ~ 0.15 mm (0.004 ~ 0.006in.)

PERIODIC MAINTENANCE 2 -9

Valve Clearance (when cold)

Intake, Exhaust

Holding the adjusting nut with a wrench, tighten the lock

•

screw to the specified torque.

Torque - Valve Clearance Lock Screws: 6.9 N·m (0.70

kgf·m, 61 in·lb)

Do not overtighten.

•

Remeasure any clearance that was adjusted. Readjust if

•

necessary.

Valve Seat Inspection

Remove the valve (see Engine Top End chapter).

•

Inspect the valve seats for damage.

•

If the seats are warped or distorted beyond recondition­ing, replace the cylinder head.
Pitted or worn 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.

•

Pull the valve out, and check the seating pattern on the

•

valve head. It must be the correct width [A] and even all
the way around.

0.10 ~ 0.15 mm (0.004 ~ 0.006in.)

2-10 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

NOTE

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

Good [A]
Toowide[B]
Too narrow [C]
Uneven [D]

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

Valve Seating Surface Width (STD)

Inlet, Exhaust

Valve Seat Repair

Follow the manufacturer’s instructions for use of valve

•

seat cutters.

Special Tools

Intake Valve:
Seat Cutter
Outside Cutter
Exhaust Valve:
Seat Cutter
Outside Cutter
Valve S eat Cutter Holder-f6.0
Valve Seat Cutter Holder Bar

If the manufacturer’s instructions are not available, use

the following procedure.

0.6 ~ 0.9 mm (0.024 ~ 0.035 in.)

:

45
32

45
32

- f27.5

- f28.0

- f27.5

- f25.0

57001-1114

:

57001-1119

:

57001-1114

:

57001-1118

:

57001-1360

:

57001-1128

Seat Cutter Operating Cares:

1. This valve seat cutter is designed only for valve seat re-

pair. Therefore the cutter must not be used for other pur­poses.

2. Do not drop or hit the valve seat cutter, or the diamond

particles 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

Do not use a wire brush to remove the metal particles
from the cutter. It will take off the diamond particles.

4. Setting t he valve seat cutter holder [A] in position, op-

erate the cutter [B] with one hand [C]. Do not apply too
much force to the diamond portion.

NOTE

Prior to grinding, apply oil to the cutter, and during t he
operation wash off any ground particles sticking to the
cutter with washing oil.

5. After use wash the cutter with washing oil and apply a

thin layer of engine oil before storing.

Periodic Maintenance Procedures

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 Cutter diameter of cutter [B]

KS8B Manufactured lot number

Operating Procedures:

Clean the seat area carefully.

•

Recondition the valve seats with the valve seat cutters

•

(45

,32) and lap the valves.

Check the seats for good contact all the way around with

•

machinist’s dye.
Measure the seat width [A]. If it is more than the STD

•

width, the seating surface should be refaced.
If the valve seating pattern is not correct, repair the seat.

•

Cutter angle [A]

PERIODIC MAINTENANCE 2-11

Coat the seat with machinist’s dye.

•

Fit a 45 seat cutter [A] to the holder and slide it into the

•

valve guide.
Resurface the valve seat with a 45 cutter, removing only
enough material to produce a smooth and concentric
seat.

CAUTION

Do not grind the seat too much. Overgrinding will
reduce valve clearance by sinking the valve into the
head. If the valve sinks too far into the head, i t will
be impossible to adjust the clearance, and the cylin­der head must be replaced. Do not turn the cutter
counterclockwise or drop it against the seat, or it
will be dulled.

2-12 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Use a 32 seat cutter [A] to narrow the seat width to the

•

STD width.

Turn the seat cutter one turn at a time while pressing down

very lightly. Check the seat width after each turn.

CAUTION

The 32 cutter removes material very quickly.

Check the seat width frequently to prevent over

grinding.

NOTE

Keep the seat width as close as possible to the STD
width.

Make a light pass with the 45 cutter to remove any pos-

•

sible burrs at the edge of the seat.

After resurfacing the seat, inspect for even valve seating.

•

Apply a machinist’s dye to the valve face, insert the

valve, and snap it closed against the seat several times.

The valve surface should show good contact all the way

around. Be sure the valve seat is centered 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.

Coat the face of valve sparingly with a fine lapping com-

•

pound.

Use the vacuum cup tool [A], to grip top of the valve [B].

•

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.

When lapping is completed, wash all parts in solvent to

•

remove lapping compound. Dry the parts thoroughly.

Note the position of the lapping m ark 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).

Periodic Maintenance Procedures

Lubrication System

Oil Level Inspection

Place the engine on a level surface.

•

Remove the oil filler cap [A] and wipe its dipstick [B] with

•

a clean cloth.
Insert the dipstick into gauge hole [C] without screwing it

•

in, then check the oil Level.

The oil level should be the operating range [A] (grid area)

•

on the dipstick.
If the oil level is below “ADD” range [B], add enough en­gine oil to bring oil level to the operating range.

CAUTION

Do not add more oil above the operating range. Ex­cess oil will cause a smoking condition.

PERIODIC MAINTENANCE 2-13

Use the same type and make of oil that is already in the
engine.

NOTE

If the engine oil type and make are unknown, use any
brand of the specified oil to top up the level in preference
to running the engine with the oil level low. Then at your
earliest convenience, change the oil completely.

If the oil level is above “FULL” range [C], drain the excess
oil by loosening the drain plug.

Oil Change

Change the oil after first 8 hours of operation. Thereafter

•

change oil every 100 hours.
Start and warm up the engine so the oil will drain easily.

•

Stop the engine.
Place the engine on a level surface.

•

Place a suitable container under the engine.

•

Remove the drain plug [A] and drain the oil.

•

WARNING

Be careful of hot oil when drained. It m ay be hot
enough to burn you severely.

Check the washer [B] at the drain plug for damage. Re-

•

place the washer with a new one if it is damaged.
Install the drain plug with the washer and tighten it.

•

Torque - Oil Drain Plug : 22 N·m (2.2 kgf·m, 16 ft·lb)

2-14 PERIODIC MAINTENANCE

Periodic Maintenance Procedures

Remove the oil filler cap and pour in the specified type

•

and amount of oil.

Engine Oil :

Type:
Viscosity:
Capacity:

Electrical System

Spark Plug Cleaning and Inspection

Remove the spark plug (See Electrical System chapter).

•

If the plug is oily or has carbon build up on it, clean the

plug using a high flash-point solvent and a wire brush or

other suitable tool.

If the spark plug electrodes are corroded or damaged,

or if the insulator is cracked, replace the plug. Use the

standard spark plug or its equivalent.

Insulator [A]
Center Electrode [B]
Plug Gap [C]
Side Electrode [D]

SF, SG, SH or SJ Class
SAE30, SAE10W-30
[When engine is completely dry]

0.65 L (0.69 US-qt)

Spark Plug Gap Inspection

Measure the gap with a wire-type thickness gauge.

•

If the gap is incorrect, carefully bend the side electrode

with a suitable tool to obtain the correct gap.

Spark Plug Gap

Standard: 0.75 mm (0.030 in.)

FUEL SYSTEM 3-1

Fuel System

TABLE OF CONTENTS

Exploded View........................................................................................................................... 3- 2

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

Governor Link Mechanism......................................................................................................... 3-7

Control Panel Assembly Removal ....................................................................................... 3- 7

Control Panel Assembly Installation .................................................................................... 3- 7

Governor Arm Removal ....................................................................................................... 3- 7

Governor Arm Installation .................................................................................................... 3- 8

Governor Assembly Inspection and Removal...................................................................... 3- 8

Governor Assembly Installation ........................................................................................... 3- 9

Governor Shaft Removal ..................................................................................................... 3- 9

Governor Shaft Installation .................................................................................................. 3- 9

Carburetor ................................................................................................................................. 3-10

Fuel and Air Flow ................................................................................................................. 3-10

High Idle Speed Adjustment ................................................................................................ 3-11

High Altitude Operation ........................................................................................................ 3-11

Main Jet Replacement ......................................................................................................... 3-11

Fuel System Cleanliness Inspection .................................................................................... 3-12

Carburetor Removal............................................................................................................. 3-12

Carburetor Installation..........................................................................................................3-12

Carburetor Disassembly/Assembly ..................................................................................... 3-13

Carburetor Cleaning............................................................................................................. 3-14

Carburetor Inspection .......................................................................................................... 3-15

Priming Pump ........................................................................................................................... 3-16

Priming Pump Removal ....................................................................................................... 3-16

Priming Pump Installation .................................................................................................... 3-16

Intake Manifold .......................................................................................................................... 3-17

Intake Manifold Removal ..................................................................................................... 3-17

Intake Manifold Installation .................................................................................................. 3-17

Intake Manifold Inspection ................................................................................................... 3-17

Fuel Tank ................................................................................................................................... 3-18

Fuel Tank Removal .............................................................................................................. 3-18

Fuel Tank Installation ........................................................................................................... 3-18

Fuel Tank Cleaning .............................................................................................................. 3-19

Fuel Filter................................................................................................................................... 3-20

Fuel Filter Inspection............................................................................................................3-20

Air Cleaner................................................................................................................................. 3-21

Element Removal ................................................................................................................ 3-21

Element Installation.............................................................................................................. 3-21

Element Cleaning and Inspection ........................................................................................ 3-21

Cleaner Body Removal ....................................................................................................... 3-21

Cleaner Body Installation..................................................................................................... 3-21

Housing (Case and Body) Inspection .................................................................................. 3-22

3

3-2 FUEL SYSTEM

Exploded View

Exploded View

Torque

No. Fastener

1 Govenor Arm Clamp Nut 7.8 0.80 69 in·lb
2 Fuel Tank Cover Bolts 6.9 0.70 61 in·lb
3 Tank Drain Bolt 6.9 0.70 61 in·lb

N·m kgf·m ft·lb

FUEL SYSTEM 3-3

Remarks

3-4 FUEL SYSTEM

Exploded View

FUEL SYSTEM 3-5

Exploded View

Torque

No. Fastener

1 Priming Nut 1.2 0.12 11 in·lb
2 Throttle Valve Screw 0.7 0.07 6in·lb
3 Main Jet 1.1 0.11 9.7 in·lb
4 Float Chamber Mounting Bolt 5.4 0.55 48 in·lb
5 Drain Screw 4.2 0.43 37 in·lb

N·m kgf·m ft·lb

Remarks

3-6 FUEL SYSTEM

Specifications

Item

Caburetor Specification:

Make/ type Walbro LMJ-17A

Throttle bore diameter 20 mm (0.79 in.)

Venturi diameter 14 mm (0.55 in.)

Main Jet (MJ) #76

Pilot jet (PJ) #50

Pilot air screw turns out (PS) 23/4

(Idle mixture screw turns out)

Float level Float parallel to carburetor body

High idle speed 3200 r/min (rpm)

Air Cleaner:

Type Dual stage filtration system

Pre-cleaner Foam element

Second-stage cleaner Paper element

Fuel:

Fuel requirement Unleaded regular grade gasoline

Governor:

Type Flyweight all speed governor

Standard

FJ180V

Governor Link Mechanism

Control Panel Assembly Removal

Remove:

•

Air Cleaner (see Cleaner Body R emoval)
Recoil Starter (see Electrical System chapter)
Fuel Tank (see Fuel Tank Removal)
Control Panel Mounting Bolts [A]

Remove the control panel [B] unhooking the governor

•

spring [A] end loop at the panel bracket.

FUEL SYSTEM 3-7

Control Panel Assembly Installation

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

•

Tighten the control panel mounting bolts.

•

Hook the governor spring end loop [A] at the panel bracket

•

[B].
After installation, adjust the high idle speed to the speci-

•

fications (see Periodic Maintenance chapter).

Governor Arm Removal

Remove:

•

Control Panel Assembly

Loosen the clamp nut [A] and take off the governor arm

•

[B].
Unhook the throttle link rod spring [C] end loop and clear

•

the throttle link rod lower end [D].

3-8 FUEL SYSTEM

Governor Link Mechanism

Governor Arm Installation

Install the governor arm [A] onto the governor shaft [B]

•

temporarily.

Be sure the link spring [C] around the throttle link rod [D]

•

is in place and that it pulls the governor arm and throttle

lever [E] toward each other.

Loosen the clamp nut [F] on the governor arm enough to

•

move the governor shaft.

Turn the top end of the governor arm counterclockwise

•

[G] to fully open the carburetor throttle valve and hold it

there.

Turn the governor shaft counterclockwise, fully turn t he

•

shaft to end of its travel.

There should be no gap between the governor arm and

the snap pin on the governor shaft.

Tighten the clamp nut.

•

Torque - Governor Arm Clamp Nut: 7.8 N·m (0.80 kgf·m, 69

in·lb)

Install the control panel assembly, and connect the gov-

•

ernor arm with the governor spring.

Governor Assembly Inspection and Removal

Remove the crankcase cover (see Camshaft/Crankshaft

•

chapter).

Visually check the governor assembly as built in the

•

crankcase cover for damage or wear.

CAUTION

Do not remove the governor assembly unless the

parts are to be replaced. The parts cannot be

reused once they are removed.

When removing the governor gear assembly [A] for re-

•

placing, use two screw drivers [B] of an appropriate size.

CAUTION

Protect the gasket-mount surface of the crankcase

cover when removing the governor assembly with

the screw drivers.

Governor Link Mechanism

Governor Assembly Installation

Instal the sleeve [A] on the governor assembly [B].

•

CAUTION

First install the sleeve. The sleeve cannot be in­stalled after the governor gear assembly has been
installed.

To install, first place the thrust washer [C] on the boss of

•

the s haft [D]. Then, install the governor assembly (with
the sleeve attached) on the shaft so that step [E] is fitted
securely in groove [F].
After installing the assembly, turn the governor by hand

•

to make sure that the governor weight [G] and the sleeve
move smoothly.

Governor Shaft Removal

Remove:

•

Air Cleaner (see Fuel System chapter)
Recoil Starter (see Electrical System chapter)
Fuel Tank (see Fuel System chapter)
Governor Arm (see Governor Arm Removal)
Flywheel (see Electrical System chapter)
Crankcase Cover (see Camshaft/Crankshaft chapter)
Crankshaft (see Camshaft/Crankshaft chapter)

FUEL SYSTEM 3-9

Remove:

•

Snap Pin [A]
Governor Shaft [B]
Washer [C]

Governor Shaft Installation

Apply engine oil to the governor shaft.

•

Install:

•

Washer [A]
Governor Shaft [B]
Snap Pin [C]

Check that the governor shaft moves freely in its operating

•

range.

3-10 FUEL SYSTEM

Carburetor

Fuel and Air Flow

The main system of the carburetor consists of the main jet
[A], main nozzle [B], and the main air passage [C] (main air
jet [D]). The main system meters fuel to the engine during
moderate to high 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 [E], pilot screw [F]
(Idle mixture screw), pilot air jet [G], pilot outlet [H], and the
bypass holes [I]. The pilot system meters the fuel/air mixture
while the engine is idling and running under a light load.
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 [J] 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 side stream 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 m ixture 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 does not me­ter the bypass holes. A moderate amount of air comes in
around the throttle valve at idle, so adjusting the pilot screw
changes the fuel/air ratio. Turning the pilot screw (Idle mix­ture screw) out (Counterclockwise) enriches the mixture;
turning it in (clockwise) leans the mixture.

Main Fuel Flow ®
Pilot Fuel Flow Þ

Carburetor

High Idle Speed Adjustment

Refer to High Idle Speed Adjustment in the Periodic Main­tenance Chapter (2nd chapter).

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 installing a smaller diameter main jet in
the carburetor and correct high idle speed.

NOTE

The main jet high altitude kits are available if the equip­ment is to be used in the high altitudes. The main jet
numbers are stamped on ends of the main jets.

High Altitude Main Jet

Main Jet No.

Altitude FJ180V

FUEL SYSTEM 3-11

0 ~ 1 000 m (0 ~ 3 000 ft)

1000~ 2 000 m (3 000 ~ 6000ft)

2 000 m (6 000 ft) and higher

Main Jet Replacement

Place the engine on a level surface.

•

Remove the tube [A] from the primer pipe.

•

Drain the fuel in the carburetor completely by unscrewing

•

the drain screw [B] at the bottom of the float chamber.

Remove the carburetor (see Carburetor Removal).

•

Unscrew the f loat chamber mounting bolt [C] and take off

•

the float chamber [D] and gasket.

Using a properly sized blade screw driver, carefully re-

•

place the main jet [A] with a new one for altitude expected.

Tighten the main jet to the specification (see Carburetor

•

Disassembly Assembly Notes).

Install the float chamber and gasket.

•

Tighten float chamber mounting bolt.

•

Torque - Float Chamber Mounting Bolt: 5.4 N·m (0.55

kgf·m, 48 in·lb)

Install the tube on the primer pipe (see Priming Pump

•

Installation).

92063–7048

92063–7049

92063–7050

3-12 FUEL SYSTEM

Carburetor

Install the primer pipe [A] and drain screw as shown.

•

90

~ 100 [B]

Fuel System Cleanliness Inspection

Refer to Fuel System Cleanliness Inspection in the Peri­odic Maintenance Chapter (2nd chapter).

Carburetor Removal

WARNING

Gasoline is extremely flammable and can be ex­plosive under certain conditions. Turn the engine
switch stop position. 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.

Remove the tube from the primer pipe.

•

Place a suitable container beneath the fuel hose.

•

Disconnect the fuel hose from the carburetor.

•

Drain the fuel in the carburetor completely by unscrewing

•

the drain screw at the bottom of the float chamber.
Remove the intake manifold (see Intake Manifold Re-

•

moval).
Remove the carburetor.

•

Unhook the throttle link spring [B] and throttle link rod [C]

•

at the throttle shaft lever [A] top end with a long nose
pliers.

Carburetor Installation

Clean the mating surfaces of the carburetor and intake

•

manifold, and fit the new gaskets.
Take care not to bend the throttle during installation. Make

•

sure the link spring around the throttle link rod is in place
and that it pulls the governor arm and carburetor throttle
shaft lever toward each other.
Adjust:

•

High Idle Speed

Carburetor

Carburetor Disassembly/Assembly

Refer to the illustration shown for disassembly and as-

•

sembly.

There are several passage plugs (Ball plugs) in the car-

•

buretor body. Do not remove.

Before disassembly, m ark the out side of throttle valve for

•

assembling them.

Replace the pilot screw in accordance with the following

•

procedure if necessary.

Carefully m ark the position of the pilot screw limiter on

the carburetor body so that it can be installed and set to

its original position later.

Remove the limiter. Be careful not to turn pilot screw at

this point.

Turn the pilot screw clockwise and count the number of

turns until screw is gently seated in the pilot passage.

Record the number of turns needed to closed the screw.

Turn out the pilot screw to replace it with a new one.

Install the new pilot screw until the screw is gently

seated. Then open the screw the same number of turns

as recorded prior to removal.

Align the limiter with the mark on the carburetor body to

install, taking care not to turn the pilot screw.

Install the throttle valve on the shaft as the out side mark

•

of them facing out side.

Drive the float pin into the carburetor body from the limiter

•

side.

Assemble carburetor parts with recommended tightening

•

torque (see Exploded View).

FUEL SYSTEM 3-13

1. Throttle Valve Screw

2. Throttle Valve

3. Throttle Shaft

4. Seal

5. Screw

6. Spring

7. Limiter

8. Spring

9. Main Nozzle

10. Main Jet

11. Float

12. Needle Jet

13. Float Pin

14. Gasket

15. Float Chamber

16. Gasket

17. Float Chamber Mounting Bolt

18. Drain Screw

19. Primer Pipe

3-14 FUEL SYSTEM

Carburetor

Carburetor Cleaning

WARNING

Clean the carburetor in a well-ventilated area, and
take care that there is no sparks or flame anywhere
near the working area, this includes any appliance
with a pilot light. Because of the danger of highly
flammable liquids, do not use gasoline or low flash

-point solvents to clean the carburetor.

CAUTION

Do not use compressed air on an assembled carbu­retor, or the float may be crushed by the pressure.
Remove as many rubber or plastic parts from the
carburetor as possible before cleaning the carbu­retor with a cleaning solution. This will prevent to
damage or deterioration 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.

Disassemble the carburetor.

•

Immerse all the carburetor metal parts in a carburetor

•

cleaning solution and clean them.
Rinse the parts in water and dry them with compressed

•

air.
Do not use rags or paper to dry parts. Lint may plug the

•

hole or passages.
Blow air t hrough the holes and fuel passages with the

•

compressed air. All holes must be open.
Assemble the carburetor.

•

Carburetor

Carburetor Inspection

WARNING

Gasoline is extremely flammable and can be explo-

sive under certain. Turn the engine switch stop

position. 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 shaft to check that the throttle butterfly

•

valve move smoothly.

If the valve do not move smoothly, replace the carburetor

body and/or throttle shaft.

Check 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 dam-

•

age. Replace the part if necessary.

Clean and check the float level as follows.

•

CAUTION

FUEL SYSTEM 3-15

Do not push down on the float during float level

checking.

With the float [A] assembly installed onto the carburetor

•

body, hold the carburetor upside down at eye level. Gen-

tly support the float with a finger and bring it down slowly

so that the float arm tab [B] touches the float valve [C]. The

float lower surface [D] should be parallel with the carbu-

retor body mating surfaces.

If the float position is not correct, replace the float with a

new one.

Inspect the float 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 s hould move

smoothly when push in and released.

Good [A]

Bad [B]
If either the needle or the seat is worn or damaged, re­place the float assembly and carburetor body as a set.

3-16 FUEL SYSTEM

Priming Pump

PrimingPumpRemoval

Remove the tube [A] from the priming pump.

•

Remove the nut [B] and washer [C].

•

Remove the priming pump from the intake manifold.

•

Inspect the priming pump for dam ages.

•

If a damage is present in the priming pump, replace it.

Priming Pump Installation

Install the priming pump in the intake manifold.

•

Install the washer [A] and tighten the nut [B].

•

Torque - Priming Nut: 1.2 N·m (0.12 kgf·m, 11 in·lb)

Install the tube [C] on the priming pump.

•

Install the tube [B] on the primer pipe [A ] as shown.

•

8 ~ 10 mm [C]

Intake Manifold

Intake Manifold Removal

Unscrew the intake manifold mounting bolts [A].

•

Remove the breather pipe [B] f rom the intake manifold.

•

Intake Manifold Installation

Replace the O-ring [A] with a new one.

•

Clean the mating surface of the carburetor and intake

•

manifold.

FUEL SYSTEM 3-17

Clean the mating surface of the carburetor and intake

•

manifold and install the new gasket [A] and intake mani­fold.

Install the spacers [A] and tighten the intake manifold

•

mounting bolts [B].
Do not clearance between intake manifold and fuel tank.

•

Intake Manifold Inspection

Inspect the intake manifold for cracks.

•

Cracks not visible to the eye may be detected by using a

•

metal crack detection system (Visual color check: com­monly found at automotive parts store.).
If a crack is present in the intake manifold, replace it.
Inspect the gasket surfaces for burrs and nicks.

•

3-18 FUEL SYSTEM

Fuel Tank

Fuel Tank Removal

Remove:

•

Air Cleaner (see Cleaner Body Removal)
Recoil Starter (see Electrical System chapter)
Oil Gauge
Fuel Tank Cover Bolts [A].

Place a suitable container beneath the fuel hose.

•

Loosen the clamp and remove the fuel hose from the car-

•

buretor.
Loosen the clamp and remove the fuel hose from the tank

•

drain.
Remove the fuel tank.

•

Remove the tank drain from the fuel tank.

•

Fuel Tank Installation

Install the tank drain [A] in the fuel tank as shown.

•

When tighting the tank drain, nut must contact fuel tank

•

cover.

Torque - Tank Drain Bolt: 6.9 N·m (0.70 kgf·m, 61 in·lb)

Install the fuel tank.

•

When installing the fuel tank, don’t clearance between

•

intake manifold [A] and fuel tank [B].

Install the fuel hose on the tank drain.

•

Install the fuel hose on the carburetor.

•

Tighten the fuel tank cover bolts.

•

Torque - Fuel Tank Cover Bolts: 6.9 N·m (0.70 kgf·m, 61

in·lb)

Install the other removed parts.

•

Fuel Tank

Fuel Tank Cleaning

WARNING

Clean the fuel tank in a well-ventilated area, and
take care that there is no sparks or flame anywhere
near the working area. Because of the danger of
highly flammable liquids, do not use gasoline or low
flash-point solvent to clean the tank.

Remove the fuel tank (see Fuel Tank Removal).

•

Pour the solvent out of the tank.

•

Pour some high flash-point solvent into the fuel tank and

•

shake the tank to remove dirt and fuel deposits.
Dry the fuel tank with compressed air.

•

Install the fuel tank (see Fuel Tank Installation).

•

FUEL SYSTEM 3-19

3-20 FUEL SYSTEM

Fuel Filter

Fuel Filter Inspection

Refer to Fuel Filter Inspection in the Periodic
Maintenance Chapter (2nd chapter).

Air Cleaner

Element Removal

Refer to Air Element Removal in the Periodic Mainte­nance Chapter (2nd chapter).

Element Installation

Refer to Air Element Instalation in the Periodic Mainte­nance Chapter (2nd chapter).

Element Cleaning and Inspection

Refer to Air Element Cleaning and Inspection in the Peri­odic Maintenance Chapter (2nd chapter).

Cleaner Body Removal

Move the holders [A].

•

FUEL SYSTEM 3-21

Push up the latches [A] and remove the air cleaner case

•

[B].
Remove:

•

Paper Element

Foam Element

Cleaner Body Installation

Install:

•

Foam Element

Paper Element
Install the hollow [A] of the air cleaner case and projection

•

[B] of the air cleaner body are fitting.

3-22 FUEL SYSTEM

Air Cleaner

Move the holders [A].

•

Housing (Case and Body) Inspection

Refer to Air Cleaner Housing (Case and Body) Inspection
in the Periodic Maintenance Chapter (2nd chapter).

COOLING SYSTEM 4-1

Cooling System

TABLE OF CONTENTS

Exploded View........................................................................................................................... 4- 2

Cooling Fan ............................................................................................................................... 4- 4

Cooling Fan Removal .......................................................................................................... 4- 4

Cooling Fan Installation ....................................................................................................... 4- 4

Cooling Fan Inspection ........................................................................................................ 4- 4

4

4-2 COOLING SYSTEM

Exploded View

COOLING SYSTEM 4-3

Exploded View

Torque

No. Fastener

1 Flywheel Bolt 42 4.3 31
2 Fuel Tank Cover Bolts 6.9 0.70 61 in·lb

N·m kgf·m ft·lb

Remarks

4-4 COOLING SYSTEM

Cooling Fan

Cooling Fan Removal

Refer to Flywheel Removal in Electrical S ystem Chapter.

Cooling Fan Installation

Refer to Flywheel Installation in Electrical System Chap­ter.

Cooling Fan Inspection

Visually inspect the blades [A] in the cooling fan [B].

•

If they are any cracks, warps or damage, replace the cool­ing fan.
If any mud or dust have stuck to the cooling fan, clean it.
Cooling fan is cleaned by washing in detergent and water.

•

CAUTION

Do not clean the cooling fan in oil solvent. It may
be damage by oil solvent.

ENGINE TOP END 5-1

Engine To p End

TABLE OF CONTENTS

Exploded View........................................................................................................................... 5- 2

Specifications ............................................................................................................................ 5- 4

Special Tools ............................................................................................................................. 5- 5

Cylinder Head............................................................................................................................ 5- 6

Compression Measurement................................................................................................. 5- 6

Cylinder Head Assembly Rem oval ...................................................................................... 5- 7

Cylinder Head Assembly Installation ................................................................................... 5- 7

Push Rod Removal .............................................................................................................. 5- 8

Push Rod Installation ........................................................................................................... 5-8

Push Rod Inspection............................................................................................................ 5- 8

Valve Mechanism Removal/Installation ............................................................................... 5- 9

Cleaning and Inspection ...................................................................................................... 5- 9

Rocker Arm Inspection......................................................................................................... 5-10

Va lves........................................................................................................................................ 5-11

Valve Clearance Inspection ................................................................................................. 5-11

Valve Clearance Adjustment ................................................................................................ 5-11

Valve Seat Inspection .......................................................................................................... 5-11

Valve Seat Repair ................................................................................................................ 5-11

Valve Head Thickness ......................................................................................................... 5-11

Valve Stem Runout .............................................................................................................. 5-11

Valve Stem Diameter ........................................................................................................... 5-11

Valve Guide Inside Diameter ............................................................................................... 5-12

Valve Spring Inspection ....................................................................................................... 5-12

Automatic Compression Release (ACR) Device Inspection ................................................ 5-12

Cylinder, Piston.......................................................................................................................... 5-13

Piston Removal.................................................................................................................... 5-13

Piston Installation................................................................................................................. 5-14

Piston Cleaning.................................................................................................................... 5-16

Piston Ring and Ring Groove Wear..................................................................................... 5-17

Piston Ring End Gap ........................................................................................................... 5-17

Piston Pin, Piston Pin Hole, and Connecting Rod Wear...................................................... 5-18

Piston Diameter ................................................................................................................... 5-18

Cylinder Inside Diameter...................................................................................................... 5-19

Muffler ....................................................................................................................................... 5-20

Muffler Removal ................................................................................................................... 5-20

Muffler Installation ................................................................................................................ 5-20

Inspection............................................................................................................................. 5-20

5

5-2 ENGINE TOP END

Exploded View

ENGINE TOP END 5-3

Exploded View

Torque

No. Fastener

1 Cylinder Head Bolts 22 2.2 16 S
2 Valve Clearance Lock Screws 6.9 0.70 61 in·lb
3 Connecting Rod Big End Cap Bolts 5.9 0.60 52 in·lb O
4 Rocker Arm Bolts 28 2.8 20
5 Spark Plug 22 2.2 16
6 Rocker Cover Mounting Bolts 5.9 0.60 52 in·lb
7 Muffler Cover Self Tap Bolt (1) 6.9 0.70 61 in·lb

O: Apply engine oil.

S: Follow the specific tightening sequence.

N·m kgf·m ft·lb

Remarks

5-4 ENGINE TOP END

Specifications

Item Service Limit

Cylinder Head:

Cylinder compression (MIN) [196 kPa (28.4 psi)] (MIN)
Cylinder head warp 0.03 mm (0.001 in.)

Valves:

Valve head thickness Intake 0.35 mm (0.014 in.)

Exhaust 0.36 mm (0.014 in.)
Valve stem runout Intake, Exhaust 0.05 mm (0.002 in.)
Valve stem diameter Intake, Exhaust 5.93 mm (0.233 in.)
Valve guide inside diameter Intake, Exhaust 6.08 mm (0.239 in.)
Valve spring free length Intake, Exhaust 33.5 mm (1.32 in.)
Rocker arm push rod rounout Intake, Exhaust 0.5 mm (0.02 in.)
Exhaust valve lift height by ACR 0.9 mm (0.04 in.)

Cylinder, Piston

Piston diameter 64.79 mm (2.551 in.)
Piston ring/groove clearance Top, Second 0.17 mm (0.007 in.)
Piston ring thickness Top, Second 1.40 mm (0.055 in.)
Piston ring end gap Top, Second 0.75 mm (0.029 in.)

Oil 1.05 mm (0.041 in.)
Piston pin outside diameter 15.96 m m (0.628 in.)
Piston pin hole inside diameter 16.08 mm (0.633 in.)
Connecting rod small end inside diameter 16.06 mm (0.632 in.)
Cylinder inside diameter Standard Cylinder 65.10 mm (2.563 in.)

0.50 mm Oversize 65.60 mm (2.583 in.)

Cylinder bore out round 0.056 mm (0.0022 in.)

Item Standard

Valve clearance Intake, Exhaust 0.10 ~ 0.15 mm (0.004 ~ 0.006 in.)
Valve seating surface angle Intake, Exhaust 45
Valve seating surface width Intake, Exhaust 0.6 ~ 0.9 mm (0.024 ~ 0.035 in.)
Valves guide inside diameter Intake, Exhaust 6.00 ~ 6.012 mm

(0.2362 ~ 0.2367 in.)

Cylinder bore diameter standard cylinder

Standard cylinder 64.98 ~ 65.00 mm

(2.558 ~ 2.559 in.)

0.50 mm Oversize 65.48 ~ 65.50 mm

(2.578 ~ 2.579 in.)

Special Tools

ENGINE TOP END 5-5

Compression Gauge: 57001–221

Piston Ring Compression: 57001–1095

Piston Ring Compression Belt, f55 ~ f67:
57001–1096

Compression Gauge Adapter M14 ×1.25 :
57001–1159

5-6 ENGINE TOP END

Cylinder Head

Compression Measurement

Before measuring compression, do the following.

•

Thoroughly warm up the engine so that engine oil be­tween the piston and cylinder wall will help seal compres­sion as it does during normal running.
Stop the engine.
Disconnect the spark plug cap of and remove the spark

•

plug.
Attach the compression gauge assembly firmly into spark

•

plug hole.

Special Tools - Compression Gauge: 57001–221 [A]

Compression Gauge Adapter: 57001–1159

[B]

Ground the spark plug to the engine.

•

WARNING

To avoid fire, do not ground the spark plug in prox­imity to t he plug hole. Keep the plug as far away as
possible from the plug hole.

With the throttle fully open, turn engine over with the recoil

•

starter knob several times until the compression gauge
stops rising, the compression is the highest reading ob­tainable.

Cylinder Compression (MIN)196 kPa (28.4 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 crown and cylinder head

- clean off any carbon on the piston crown 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 by worn
valve guides or worn piston oil ring. 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 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

Cylinder Head Assembly Removal

Remove:

•

Air Cleaner (see Fuel System chapter)
Recoil Starter (see Electrical System chapter)
Fuel Tank (see Fuel System chapter)
Muffler (see M uffler Removal)
Fan Housing (see Flywheel Removal)
Intake Manifold and Carburetor (see Fuel System chap­ter)
Spark Plug

Loosen the rocker cover mounting bolts [A] and remove

•

the cover [B] and gasket.
When removing the cylinder head, set at T.D.C of Power

•

stroke in.

Loosen the cylinder head bolts 1/4 turn in the sequence

•

shown.

CAUTION

If the above procedure is not followed, the cylinder
head may be warped during removal.

ENGINE TOP END 5-7

Repeat the sequence until all bolts are removed and lift

•

off the cylinder head assembly.

NOTE

Mark the push-rods so they can be installed in their orig­inal position during assembly.

Cylinder Head Assembly Installation

Clean the mating surfaces of the cylinder head and cylin-

•

der.
Install the push rods in their original positions on cylinder

•

(see Push Rod Installation).
Install the knock pins.

•

Set cylinder at T.D.C of power stroke in.

•

Put new gasket and the cylinder head assembly on cylin-

•

der, then align the push rods under the rocker arms.

Tighten the cylinder head bolts following the tightening

•

sequence as shown.

Torque - Cylinder Head Bolts: 22 N·m (2.2 kgf·m, 16 ft·lb)

CAUTION

A torque wrench must be used to assure proper
torque. Improper tightening of the head bolts can
result in warping of the cylinder head.

Check and adjust the valve clearance (see Periodic Main-

•

tenance chapter).
Install the gasket and rocker cover.

•

Torque - Rocker Cover Mounting Bolts: 5.9 N·m (0.60

kgf·m, 52 in·lb)

Install the other removed parts.

•

5-8 ENGINE TOP END

Cylinder Head

Push Rod Removal

Set at T.D.C of power stroke in.

•

Remove the rocker cover (see Cylinder Head Assembly

•

Removal).
Loosen the valve clearance adjusting nuts [A].

•

Move the rocker arms [B] to clear the push rod upper

•

ends.
Pull out the push rods.

•

NOTE

Mark the push rods so they can be installed in their orig­inal positions during assembly.

Push Rod Installation

Set at T.D.C of power stroke in.

•

Install the push rods [A] in their original positions on cylin-

•

der.
To Install the push rod in the correct position on the tappet
[B], insert the push rod so end of the push rod is sliding
down along inside wall [C] of the crankcase and position
the push rod end onto the tappet.
Check that both intake and exhaust push rod on cylinder

•

is at lowest position on the cam lobes [D], if not, turn the
flywheel clockwise one turn (360
power stroke in.
Be sure the end of the push rods are correctly seated on

•

the tappets.
Tighten the valve clearance adjusting nuts ( see Periodic

•

Maintenance chapter).
Check and adjust the valve clearance (see P eriodic Main-

•

tenance chapter).

) and reset at T.D.C of

Push Rod Inspection

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

•

possible, and set a dial gauge [A] on the rod at a point
halfway 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: 0.5 mm (0.02 in.)

Cylinder Head

Valve Mechanism Removal/Installation

Remove the cylinder head assembly (see Cylinder Head

•

Assembly Removal).

NOTE

When removing the valve mechanism parts, note their
position so that they may be r einstalled in their original
position during assembly.

Remove:

•

Valve Clearance Adjusting Nuts [A]
Rocker Arms [B]

Support the valve head in the combustion chamber with

•

a suitable block.
To remove the collets [B], push down the valve retainer

•

[A] with thumbs and remove the collets.
Removethespring[C]andvalve[D].

•

ENGINE TOP END 5-9

NOTE

Valve guide [A] is not replaceable, do not remove it.

Apply engine oil to the valve stem.

•

Install the valve.

•

Check to see that the valve moves smoothly up and down

•

in the guide.
Install the spring and valve retainer.

•

To install the collets, push down the valve retainer with

•

thumbs and install the collets.
Soak the valve clearance adjusting nuts and rocker arms
in the engine oil.
Install the rocker arms by the valve clearance adjust

•

screws.
Adjust the valve clearance (see Periodic Maintenance

•

chapter).

Cleaning and Inspection

Refer to Cylinder Head Cleaning and Inspection in the
Periodic M aintenance Chapter (2nd chapter).

5-10 ENGINE TOP END

Cylinder Head

Rocker Arm Inspection

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.

Valves

Valve Clearance Inspection

Refer to Valve Clearance Inspection in the Periodic Main­tenance Chapter (2nd chapter).

Valve Clearance Ad justment

Refer to Valve Clearance Adjustment in the Periodic
Maintenance Chapter (2nd chapter).

Valve Seat Inspection

Refer to Valve Seat Inspection in the Periodic Mainte­nance Chapter (2nd chapter).

Valve Seat Repair

Refer to Valve Seat Repair in the Periodic Maintenance
Chapter (2nd chapter).

ValveHeadThickness

Remove the valve (see Valve Mechanism Removal/Instal-

•

lation).
Measure the thickness of the valve head.

•

If the valve head thickness (valve margin) [A] is less than
the service limit, replace the valve.

ENGINE TOP END 5-11

Valve Head Thickness

Service Limit

Valve Stem Runout

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

•

Position a dial gauge perpendicular to t he stem.

•

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

•

If the stem runout is greater than service limit, replace the
valve.

Valve Stem Runout

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

Valve Stem Diame ter

Measure the diameter of the valve stem [A] in two di-

•

rections 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

Service Limit (IN, EX): 5.93 mm (0.233 in.)

IN:

EX:

0.35 mm (0.014 in.)

0.36 mm (0.014 in.)

5-12 ENGINE TOP END

Valves

Valve Guide Inside Diameter

Use a small bore gauge or a micrometer to measure the

•

inside diameter [A] of the valve guides [B] at three places
down the length of the guides.
If the measurement is more than the service limit, replace
the cylinder head with a new one.

Valve Guide Inside Diameter

Service Limit (IN, EX) : 6.08 mm (0.239 in.)

Valve Spring Inspection

Inspect the valve spring for pitting, cracks, rusting, and

•

burns. Replace the spring if necessary.
Measure the free length [A] of the spring.

•

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

Valve Spring Free Length

Service Limit: 33.5 mm (1.32 in.)

Automatic Compression Release (ACR) Device Inspection

The ACR reduces the compression of the cylinder in or­der to facilitate the revolution of the crankshaft during the
starting of the engine.

Remove:

•

Rocker Cover (see Cylinder Head Assembly Removal)
Spark Plug (see Electrical System chapter)

Check whether the valves have the specified clearance

•

(see Periodic Maintenance chapter).

Slowly turn the crankshaft in the direction and observe the

•

movement of the exhaust valve [A] and the rocker arm [B].

Immediately after the intake valve has closed, the rocker

arm should push open the exhaust valve to attain a lift that

is greater. If the exhaust valve does not lift to that height,

the ACR that is provided on the camshaft is faulty (see

Camshaft/Crankshaft chapter).

Exhaust Valve Lift Height Service Limit by ACR

Standard: 0.9 mm (0.04 in.)

Cylinder, Piston

Piston Removal

Remove:

•

Air Cleaner (see Fuel System chapter)
Recoil Starter (see Electrical System chapter)
Fuel Tank (see Fuel System chapter)
Flywheel (see Electrical System chapter)

Remove the crankcase cover (see Camshaft/Crankshaft

•

chapter).
Remove the camshaft (see Camshaft/Crankshaft chap-

•

ter).
Turn the crankshaft to expose the connecting rod cap

•

bolts [A].
Remove the bolts and take off the connecting rod cap [B].

•

NOTE

Note the position of the connecting rod cap for rein­stalling the cap.

Push the connecting rod end into the cylinder, and pull the

•

piston and connecting rod out of the cylinder.

ENGINE TOP END 5-13

Remove one of the piston pin snap rings [A] with needle

•

nose pliers [B].

Remove the piston by pushing the piston pin [A].

•

5-14 ENGINE TOP END

Cylinder, Piston

Carefully spread the ring opening with your thumbs and

•

then push up on the opposite side of the ring [A] to remove

it.

Remove the 3-piece oil ring with your thumbs in the same

•

manner.

Piston Installation

Install the expander [A] in the piston oil ring groove so that

•

the expander ends [B] touch together, never overlap.

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

•

Down to the rails. They can be installed either way.

Do not mix up the top and second ring.

•

Install the second ring so that the “0” mark faces up.

•

Install the top ring.

•

The rings should turn freely in the grooves.

•

Piston Head [A]
TopRing[B]
Second Ring [C]

Align the piston and rings with the piston ring end gap as

•

shown.

Arrow Match Mark [A]
Top ring End Gap, Upper Steel Rail End Gap [B]
45

[C]

Second Ring End Gap, Lower Steel Rail End Gap [D]

Cylinder, Piston

Apply engine oil to the piston pin.

•

Assemble the piston onto the connecting rod as follows:

•

Set the arrow mark [A] on the piston head come reverse
side of the “K” mark [B] side the connecting rod, then in­sertthepistonpinintothepistonpinhole.

Install the snap ring [A] in the piston [B] as shown.

•

CAUTION

Do not reuse the snap rings, as removal weakens
and deforms them. They could fall out and score
the cylinder wall.

ENGINE TOP END 5-15

Apply engine oil to the piston skirt and the cylinder bore.

•

Using the piston ring compressor grip [A] and the belt [B],
lightly tap the top of the piston with a plastic mallet [C] to
insert the piston and connecting rod into the cylinder.

Special Tools - Piston Ring Compressor Grip: 57001–1095

Piston Ring Compressor Belt: 57001–1096

Insert the piston and connecting rod so that the arrow

•

mark [A] on the top of the piston is facing the flywheel
side [B].

5-16 ENGINE TOP END

Cylinder, Piston

CAUTION

The connecting rod and the connecting rod big end

cap are machined at the factory in the assembled

state, so they must be replaced together as a set.

Apply engine oil to the inner surface [A] of the connecting

•

rod big end [B] and cap [C].

Set rod and cap aligning the mark [D] of rod to the mark of

•

cap, install the connecting rod big end cap in their original

position on connecting rod big end.

Apply a small amount of engine oil to the cap bolts [E].

•

Tighten the cap bolts.

•

Torque - Connecting Rod Big E nd Cap Bolts: 5.9 N·m (0.60

kgf·m, 52 in·lb)

Install:

•

Camshaft (see Camshaft/Crankshaft chapter)
Crankcase Cover (see Cam shaft/Crankshaft chapter)

Install the other removed parts.

•

Piston Cleaning

Remove the piston and piston rings (see Piston Re-

•

moval).

CAUTION

Never clean the piston head assembled. Carbon

particles will fall between the piston and cylinder,

and damage the piston and cylinder.

Scrape the carbon off [A] the piston head.

•

Use 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.

Cleanthepistonringgrooves[A]withabrokenpistonring

•

or other suitable tools.

CAUTION

Be careful not to widen the ring grooves. Damaged

ring grooves will require piston replacement.

Cylinder, Piston

Piston Ring and Ring Groove Wear

Clean the piston (see Piston Cleaning).

•

Visually inspect the piston rings and ring grooves.

•

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.
Measure the clearance between the top and second rings

•

and their grooves using a thickness gauge [A].
If the piston ring/groove clearance is greater than the
specified value, replace the piston.

Piston Ring/Groove Clearance

Service Limit

Top, Second 0.17 mm (0.007 in.)

NOTE

The oil ring is a three piece assembled ring. It is difficult
to measure the ring groove clearance and thickness,
visually inspect only.

ENGINE TOP END 5-17

Measure the piston ring thickness [A].

•

Use a micrometer to measure at several points around
the rings.
If any of the measurement are less than the service limit,
replace the entire set of rings.

Piston Ring Thickness

Service Limit

Top, Second 1.40 mm (0.055 in.)

NOTE

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.

Piston Ring End Gap

Removethepistonrings.

•

Push each ring (one at a time) in the cylinder bore t o a

•

point close to the bottom of the cylinder bore.
Use the piston to push it in to be sure it is square.
Measure the gap [A] between the ends of the ring [B] with

•

a thickness gauge.
If the end gap of any ring is greater than the service limit,
replace the entire set of rings.

Piston Ring End Gap

Service Limit
Top, Second 0.75 mm (0.029 in.)
Oil 1.05mm(0.041in.)

5-18 ENGINE TOP END

Cylinder, Piston

Piston Pin, Piston Pin Hole, and Connecting Rod Wear

Remove the piston pin.

•

Measure the diameter of the piston pin with a m icrometer

•

at several points.
If the outside diameter is less than service limit, replace
thepistonpin.

Piston Pin Outside Diameter

Service Limit: 15.96 mm (0.628 in.)

Measure the inside diameter [A] 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 Inside Diameter

Service Limit: 16.08 mm (0.633 in.)

Measure the inside diameter [A] of 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 Inside Diameter

Service Limit: 16.06 mm (0.632 in.)

Piston Diameter

Measure the outside diameter [A] of the piston 12.5 mm

•

(0.9 in.) up [B] from the bottom of the piston at a right
angle to the direction of the piston pin hole.
If the measurement is less than the service limit, replace
the piston.

Piston Diameter

Service Limit: 64.79 mm (2.551 in.)

Cylinder, Piston

Cylinder Inside Diameter

Clean and measure the cylinder inside diameter.

•

Use a dial bore gauge to measure front-to-back and side

-to-side at the points shown figure.
If any of the cylinder bore measurements is greater than
the service limit, replace the cylinder with a new one.

10 mm (0.39 in.) [A]
Middle [B]

Cylinder Inside Diameter

Standard: 64.98 ~ 65.00 mm (2.558 ~ 2.559 in.)
Service Limit: 65.10 mm (2.563 in.)

Cylinder Bore Out-of-Round

Standard: 0.01 mm (0.0004 in.)

Service Limit: 0.056 mm (0.0022 in.)

ENGINE TOP END 5-19

5-20 ENGINE TOP END

Muffler

Muffler Removal

Remove:

•

Muffler Cover Self Tap Bolt [C]
Muffler Cover Nuts [A]
Muffler Cover [B]
Muffler

Remove the gasket.

•

Do not use unnecessary force on the muffler when remov-

•

ing the muffler assembly, or they could become damaged
or distored.

Muffler Installation

Clean the gasket surface and install a new gasket each

•

time the muffler installed.
Install the muffler.

•

Install the muffler cover.

•

Tighten the muffler cover nuts and self tap bolt.

•

Torque - Muffler Cover Self Tap Bolt: 6.9 N·m (0.70 kgf·m,

61 in·lb)

After installation, thoroughly warm up the engine, wait un-

•

til the engine cools down and retighten the nuts and bolt.

Inspection

Inspect the muffler for dents, cracks, rust and holes.

•

If the muffler is damaged, it should be replaced for best
performance and least noise.
Check the muffler for distortion or loose internal compo-

•

nents. Loss of power could develop if loose internal muf­fler components restrict exhaust flow.

LUBRICATION SYSTEM 6-1

Lubrication System

TABLE OF CONTENTS

Exploded View........................................................................................................................... 6- 2

Engine Oil Flow Chart................................................................................................................ 6- 4

Specifications ............................................................................................................................ 6- 5

Engine Oil ................................................................................................................................. 6- 6

Oil Level Inspection..............................................................................................................6-6

Oil Change ........................................................................................................................... 6- 6

Lubrication System .................................................................................................................... 6- 7

Oil Pump.................................................................................................................................... 6- 8

Oil Pump Removal ............................................................................................................... 6- 8

Oil Pump Installation ............................................................................................................ 6- 8

Oil Pump Inspection............................................................................................................. 6-8

6

6-2 LUBRICATION SYSTEM

Exploded View

LUBRICATION SYSTEM 6-3

Exploded View

Torque

No. Fastener

1 Oil Drain Plug 22 2.2 16
2 Tank Drain Bolt 6.9 0.70 61 in·lb
3 Oil Filter Cover Bolt 6.9 0.70 61 in·lb

O: Apply engine oil.

N·m kgf·m ft·lb

Remarks

6-4 LUBRICATION SYSTEM

Engine Oil Flow Chart

LUBRICATION SYSTEM 6-5

Specifications

Item Standard

Engine Oil:

Type SF, SG, SH or SJ class

Viscosity SAE30, SAE10W-30

Capacity [When engine is completely dry] 0.65 L (0.69 US-qt)

Level Operating range (grid area) on dipstick

Item

Oil Pump:

Inner and outer rotor clearance 0.14 mm (0.006 in.)

Outer rotor outside diameter 22.940 mm (0.9031 in.)

Outer rotor thickness 11.960 mm (0.4709 in.)

Pump housing inside diameter 23.241 mm (0.915 in.)

Pump housing depth 12.220 mm (0.4811 in.)

Service Limit

6-6 LUBRICATION SYSTEM

Engine Oil

CAUTION

Engine operation with insufficient, deteriorated,
or contaminated engine oil will cause accelerated
wear and may result in engine seizure and accident.
Before starting the engine for the first time, add oil:
The engine is shipped dry. Preoil the engine to force
all air from the internal oil passages.

Fill fresh engine oil to the specified level (see Periodic

•

Maintenance chapter).
Run the engine at slow speed 2 minutes.

•

Stop the engine and check the oil level.

•

Oil Level Inspection

Refer to Oil Level Inspection in the Periodic Maintenance
Chapter (2nd chapter).

Oil Change

Refer to Oil Change in the Periodic Maintenance Chapter
(2nd chapter).

LUBRICATION SYSTEM 6-7

Lubrication System

Pressure the oil of oil pump is elevate the oil passages of crankcase of thread. Discharge the oil
camshaft to side from crank celing side and the revolution of the camshaft to dissemination the oil
mist from the crankshaft chamber. Lubrication t he piston and big end, small end, shaft, gear.

6-8 LUBRICATION SYSTEM

Oil Pump

Oil Pump Removal

Remove:

•

Air Cleaner (see Fuel System chapter)
Recoil Starter (see Electrical System chapter)
Fuel Tank (see Fuel System chapter)
Flywheel (see Electrical System chapter)
Crankcase Cover (see Cam shaft/Crankshaft chapter)
Camshaft (see Camshaft/Crankshaft chapter)
Connecting Rod (see Camshaft/Crankshaft chapter)
Crankshaft (see Camshaft/Crankshaft chapter)

Remove the oil pump assembly [A].

•

Oil Pump Installation

Fill the rotor housing with engine oil for initial lubrication.

•

Install the pump assembly [A] in t he crankcase.

•

Install the other removed parts.

•

Oil Pump Inspection

Remove the oil pump (see Oil Pump Removal).

•

Visually inspect the outer and inner rotor.

•

If there is any damage or uneven wear, replace t hem.
Check 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

Service Limit: 0.14 mm (0.006 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 Outside Diameter

Service Limit: 22.940 mm(0.9031 in.)

Measure the thickness [B] of the outer rotor with a mi-

•

crometer at several points
If the rotor thickness is less than the service limit, replace
both the inner and outer rotor.

Outer Rotor Thickness

Service Limit: 11.960 mm (0.4709 in.)

Oil Pump

Measure the inside diameter [A] of the pump housing with

•

an inside micrometer at several points.

If the inside diameter is more than the service limit, re-

place the crankcase.

Pump Housing Inside Diameter

Service Limit: 23.241 mm (0.915 in.)

Measure the depth [B] of the pump housing with a depth

•

micrometer at several points.

If any of measurement is more than the service limit, r e-

place the crankcase.

Pump Housing Depth

Service Limit: 12.220 mm (0.4811 in.)

LUBRICATION SYSTEM 6-9

CAMSHAFT/CRANKSHAFT 7 -1

Camshaft/Crankshaft

TABLE OF CONTENTS

Exploded View........................................................................................................................... 7- 2

Specifications ............................................................................................................................ 7- 4

Crankcase ................................................................................................................................. 7- 5

Crankcase Cover Removal .................................................................................................. 7- 5

Crankcase Cover Installation ............................................................................................... 7- 5

Inspection............................................................................................................................. 7- 6

Cleaning ............................................................................................................................... 7- 6

Breather..................................................................................................................................... 7- 7

Breather Chamber Cover Removal ..................................................................................... 7- 8

Breather Chamber Cover Installation .................................................................................. 7- 8

Breather Valve Inspection .................................................................................................... 7- 8

Camshaft, Tappet ...................................................................................................................... 7- 9

Camshaft, Tappet Removal.................................................................................................. 7- 9

Camshaft, Tappet Installation............................................................................................... 7-10

Camshaft Disassembly ........................................................................................................ 7-10

Camshaft Assembly ............................................................................................................. 7-10

Camshaft Inspection ............................................................................................................ 7-10

Camshaft Bearing/Journal Wear.......................................................................................... 7-11

Crankshaft, Connecting Rod ..................................................................................................... 7-12

Connecting Rod Removal .................................................................................................... 7-12

Connecting Rod Installation................................................................................................. 7-12

Crankshaft Removal ............................................................................................................ 7-12

Crankshaft Installation ......................................................................................................... 7-12

Cleaning/Inspection ............................................................................................................ 7-12

Connecting Rod Bend/Twist................................................................................................. 7-13

Connecting Rod Big End/Crankpin Width Wear .................................................................. 7-13

Connecting Rod Big End Bearing/Crankpin Wear ............................................................... 7-14

Crankshaft Runout ............................................................................................................... 7-14

Crankshaft Main Journal/Wear ............................................................................................ 7-15

7

7-2 CAMSHAFT/CRANKSHAFT

Exploded View

CAMSHAFT/CRANKSHAFT 7 -3

Exploded View

Torque

No. Fastener

1 Crankcase Cover Bolts 8.8 0.90 78 in·lb S
2 Connecting Rod Big End Cap Bolts 5.9 0.60 52 in·lb O
3 Valve Clearance Lock Screws 6.9 0.70 61 in·lb
4 Rocker Arm Bolts 28 2.8 20

G: Apply grease.

O: Apply engine oil.

S: Follow the specific tightening sequence.

N·m kgf·m ft·lb

Remarks

7-4 CAMSHAFT/CRANKSHAFT

Specifications

Item

Camshaft, Tappet:

Cam lobe height Intake, Exhaust 22.060 mm (0.8685 in.)
Camshaft journal diameter PTO side 7.77 mm (0.3059 in.)

Flywheel side 13.927 mm (0.5483 in.)

Camshaft hole inside diameter Crankcase cover 11.060 mm (0.4354 in.)

Crankshaft, Connecting Rod:

Connecting rod bend 0.2/100 mm

Connecting rod twist 0.2/100 mm

Connecting rod big end width 23.44 mm (0.92 in.)
Crankpin width 24.17 mm (0.95 in.)
Connecting rod big end inside diameter 31.040 mm (1.222 in.)
Crankpin outside diameter 30.97 mm (1.219 in.)
Crankshaft runout 0.05 mm (0.002 in.) TIR
Crankshaft journal diameter PTO side 27.96 mm (1.101 in.)

Flywheel side 27.98 mm (1.102 in.)

Crankcase:

PTO shaft hole inside diameter

Crankcase cover 27.98 mm (1.102 in.)

Crankshaft journal metal inside diameter

Crankcase 27.98 mm (1.102 in.)

Service Limit

(0.008/3.94 in.)

(0.008/3.94 in.)

Crankcase

Crankcase Cover Removal

Drain the oil (see Lubrication System chapter).

•

Remove:

•

Air Cleaner (see Fuel System Chapter)
Recoil Starter (see Electrical System Chapter)
Fuel Tank (see Fuel System Chapter)
Flywheel (see Electrical System C hapter)

Unscrew the mounting bolts [A] and remove the

•

crankcase cover [B] from the crankcase.

There are two knock pins on the crankcase mating sur-

face. A wooden or plastic mallet may be used to gently

tap loose the crankcase cover.

Crankcase Cover Installation

Chip off the old gasket from the mating surfaces of the

•

crankcase and cover.

Using compressed air, blow out the oil passage in the

•

crankcase cover.

With a high flash-point solvent, clean off the mating sur-

•

faces of the crankcase and cover, and wipe dry.

CAMSHAFT/CRANKSHAFT 7 -5

WARNING

Clean the crankcase and cover in a well-ventilated

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-point solvent to clean parts. A fire or

explosion could result.

Be sure to replace any oil seal removed with a new one.

•

Install the oil seal so that the marks [A] face out.

Thoroughly pack high temperature grease [B] into the

space between the seal lip [C] and dust lip [D]. Press in

the new oil seal using a press or suitable tools until it is

flush with flange surface [E]. Do not damage the seal lips.

Check to see that the dowel pins [A] are in place on the

•

crankcase.

Install the gasket on the crankcase.

•

7-6 CAMSHAFT/CRANKSHAFT

Crankcase

Install the crankcase cover and tighten the crankcase

•

cover bolts following the tightening sequence shown.

Torque - Crankcase Cover Bolts: 8.8 N·m (0.90 kgf·m, 78

in·lb)

Do not turn one bolt down completely before the others,
as it may cause the crankcase cover to warp.

Inspection

Measure the inside diameter [A] of the PTO shaft hole

•

on the crankcase cover at several points. Replace the
crankcase cover i f the inside diameter is more than the
service limit.

PTO Shaft Hole Inside Diameter

Service Limit: 27.98 mm (1.102 in.)

Measure the inside diameter [A] of the crankshaft journal

•

metal on t he crankcase at several points. Replace the
crankcase if the inside diameter is more than the service
limit.

Crankshaft Journal Metal Inside Diameter

Service Limit: 27.98 mm (1.102 in.)

Cleaning

Remove:

•

Camshaft and Tappets (see Camshaft, Tappet Removal)
Connecting Rod and Piston (see Engine Top End chap­ter)
Crankshaft (see Crankshaft Removal)

Clean up the crankcase and cover with a high flash-point

•

solvent, and blow out any foreign particles that may be in
the pockets inside of the crankcase with compressed air.

WARNING

Clean the crankcase and cover in a well-ventilated
area, and take care that there is no sparks or flame
anywhere near the working area. Because of the
danger of highly flammable liquids, do not use
gasoline or low flash-point solvents.

CAMSHAFT/CRANKSHAFT 7 -7

Breather

The function of the breather is to create a negative pressure in the crankcase which prevents oil from
being forced out of the engine through the piston rings, oil seals or gaskets. Valve controls direction
of air flow caused by piston movement so that air flow from inside to outside can pass reed valve
but not from outside to inside. Blow-by gas in crankcase passes through valve and expands in valve
chamber. The air passes through expands in breather chamber. Then air passes through maze in
breather chamber and is vented to intake pipe, through breather pipe.

7-8 CAMSHAFT/CRANKSHAFT

Breather

Breather Chamber Cover Removal

Remove the bolts [A] and breather chamber cover [B].

•

Breather Chamber Cover Installation

Install a new gasket and the breather chamber cover, and

•

tighten the bolts.

Breather Valve Inspection

Remove the breather valve [A].

•

Inspect the breather valve [A] for breakage, hair crack or

•

distortion, replace it if necessary.
Inspect the valve seating surface. The surface should be

•

free of nicks or burrs.
Be sure the drain hole on the breather chamber does not

•

accumulate with slugs before installing the breather valve.

Camshaft, Tappet

Camshaft, Tappet Removal

Drain the oil (see Lubrication System chapter).

•

Remove:

•

Air Cleaner (see Fuel System chapter)
Recoil Starter (see Electrical System chapter)
Fuel Tank (see Fuel System chapter)
Flywheel (see Electrical System chapter)
Crankcase Cover (see Crankcase Cover Removal)
Rocker Cover [A]

Position the piston TDC at the end of the compression

•

stroke in.

Push down [A] the spring side of the rocker arm [B] and

•

move it to clear the push rod [C].

Remove the push rods and mark them so they can be

•

installed in their original positions during assembly.

CAMSHAFT/CRANKSHAFT 7 -9

Place the crankcase with flywheel side toward top side.

•

Pull the camshaft [A] out of the crankcase.

•

Remove the tappets [A] and mark them so they can be

•

installed in their original positions during assembly.

7-10 CAMSHAFT/CRANKSHAFT

Camshaft, Tappet

Camshaft, Tappet Installation

Apply engine oil to the following.

•

Tappet Journal
Camshaft Journal
Cam Lobe Surface
Camshaft Gear

Install the tappets in those old positions.

•

Align the punch marks [A] on the crankshaft gear and on

•

the camshaft gear.
Install the push rods (see Push Rod Installation).

•

Install the rocker arms on the push rods, and install the

•

valve clearance adjust nuts.
Adjust the valve clearance (see Engine Top End chapter).

•

Install the gasket and rocker cover.

•

Install the other removed parts.

•

Camshaft Disassembly

Remove the governor assembly (see Fuel System chap-

•

ter).
Remove:

•

Spring [A]
Do not remove the ACR (automatic com pression release)
weight [B].

Camshaft Assembly

Install the governor assembly (see Fuel System chapter).

•

After assembling the camshaft, check the following items.

•

While shaking the camshaft, ACR weight swings
smoothly.

Camshaft Inspection

Check the camshaft gear [A] for pitting, fatigue cracks,

•

burrs or an evidence of improper tooth contact.
Replace the shaft if necessary.
Check the top of the cam lobes [B] for wear, burrs or un-

•

even contact.
Replace the shaft if necessary.

Camshaft, Tappet

Inspect the camshaft to make sure that its automatic com-

•

pression Reduction (ACR) function operates smoothly
and does not have any damage or abnormal wear.
If ACR parts are worn, replace the ACR with a new one.
When the weight [A] is closed, if the top of the arm [B] is
lower than the base [C], replace the ACR with a new one.
When the weight is pulled entirely outward with your fin­ger, if the top of the arm is higher than the cam base,
replace the ACR with a new one.

Camshaft Bearing/Journal Wear

Measure the height [A] of each cam lobe.

•

If the cam height is less than the service limit for either
lobe, replace the camshaft.

Cam Lobe Height

Service Limit (IN, EX) : 22.060 mm (0.8685 in.)

CAMSHAFT/CRANKSHAFT 7-11

Measure both c amshaft journals at several points around

•

the journal circumference.
If the journal diameter is less than the service limit, re­place the camshaft.

PTO Side Camshaft Journal Diameter

Service Limit: 7.77 mm ( 0.3059 in.)

Flywheel Side Camshaft Journal Diameter

Service Limit: 13.927 mm (0.5483 in.)

Measure the inside diameter [A] of the camshaft hole on

•

the crankcase cover at several points.
Replace the crankcase cover if the inside diameter is
more than the service limit.

Camshaft Hole Inside Diameter (Crankcase Cover)

Service Limit: 11.060 mm (0.4354 in.)

7-12 CAMSHAFT/CRANKSHAFT

Crankshaft, Connecting Rod

Connecting Rod Removal

Remove:

•

Piston (see Engine Top End chapter)

Connecting Rod Installation

Install:

•

Piston (see Engine Top End chapter)

Crankshaft Removal

Drain the oil (see Lubrication System chapter).

•

Remove:

•

Air Cleaner (see Fuel System chapter)

Recoil Starter (see Electrical System chapter)

Fuel Tank (see Fuel System chapter)

Flywheel (see Electrical System chapter)

Crankcase Cover (see Cam shaft/Crankshaft chapter)

Camshaft (see Camshaft/Crankshaft chapter)

Connecting Rod (see Camshaft/Crankshaft chapter)
Pull the crankshaft [ A] out of the crankcase. Tap gently

•

with a wooden or plastic mallet if necessary to loosen the
crankshaft.

Crankshaft Installation

Clean up the crankshaft and crankcase thoroughly.

•

Check that the pivot arm for the governor is installed (see

•

Fuel System chapter).
Pack some amount of high temperature grease into the

•

oil seal on the crankcase.
Apply engine oil journal.

•

Install the crankshaft in the crankcase.

•

Cleaning/Inspection

After removing, clean the connecting rod and crankshaft

•

with a high flash-point solvent and dry them with com­pressed air.
Inspect the teeth of the crankshaft gear for pitting, fatigue

•

cracks, burrs and evidence of improper tooth contact.
Replace the gear if necessary.
Inspect the crankshaft and connecting rod for wear,

•

scratches, evidence of improper contact or other dam­ages.
Replace them if necessary.

Crankshaft, Connecting Rod

Connecting Rod Bend/Twist

Measure connecting rod bend.

•

Select an arbor of the same diameter as the connecting
rod big end, and insert the arbor through the connecting
rod big end.
Select an arbor of the same diameter as the piston pin
and at least 100 mm long, and insert the arbor through
the connecting rod small end.
On a surface plate, set the big-end arbor on V blocks [A].
With the connecting rod held vertically, use a height
gauge to measure the difference in the height of the
small end arbor above the surface plate over a 100 mm
length to determine the amount of connecting rod bend
by dial gauge [B].
If connecting rod bend exceeds the service limit, the con­necting rod must be replaced.

Connecting Rod Bend

Service Limit: 0.2/100 mm (0.008/3.94 in.)

CAMSHAFT/CRANKSHAFT 7-13

Measure connecting rod twist.

•

With the big-end arbor still on the V blocks [A], hold the
connecting rod horizontally and measure the amount that
the small end arbor varies from being parallel with the sur­face plate over a 100 mm length of the arbor to determine
the amount of connecting rod twist by dial gauge [B].
If connecting rod twist exceeds the service limit, the con­necting rod must be replaced.

Connecting Rod Twist

Service Limit: 0.2/100 mm (0.008/3.94 in.)

Connecting Rod Big End/Crankpin Width Wear

Measure the connecting rod big end width [A] with a mi-

•

crometer or dial caliper.
If the measurement is less than the service limit, replace
the connecting rod.

Connecting Rod Bi g End Width

Service L imit: 23.44 mm (0.92 in.)

7-14 CAMSHAFT/CRANKSHAFT

Crankshaft, Connecting Rod

Measure the crankpin width [A] with a dial caliper.

•

If the crankpin width is more than the service limit, replace
the crankshaft.

Crankpin Width

Service Limit: 24.17 mm (0.95 in.)

Connecting Rod Big End Bearing/Crankpin Wear

Apply a light film of oil on the thread of the cap bolts.

•

Install the cap bolts and tighten the bolts to the specified

•

torque (see Piston Installation in Engine Top End chap­ter).
Measure the inside diameter [A] of big end at several

•

points with a telescoping gauge or inside micrometer.
If the inside diameter is more than the service limit, re­place the connecting rod with a new one.

Connecting Rod Big End Inside Diameter

Service Limit: 31.040 mm (1.222 in.)

Measure the crankpin outside diameter [A].

•

Use a micrometer to measure several points around the
crankpin circumference.
If the crankpin diameter is less than the service limit, re­place the crankshaft with a new one.

Crankpin Outside Diameter

Service Limit: 30.97 mm (1.219 in.)

Crankshaft Runout

Measure the crankshaft runout.

•

Set the crankshaft in a flywheel alignment jig [A] or on V
blocks gauge.
Set a dial gauge [B] against both journals.
Turn the crankshaft slowly to measure the runout. The dif­ference between the highest and lowest dial gauge read­ings (TIR) is the amount of runout.
If the measurement exceeds the service limit, replace the
crankshaft.

Crankshaft Runout

Service Limit: 0.05 mm (0.002 in.) TIR