4-stroke air-cooled gasoline engine

Quick Reference Guide

General Information 1 jPeriodic Maintenance 2 jFuel System 3 jCooling System 4 jEngine Top End 5 jLubrication System 6 jCamshaft/Crankshaft 7 jElectrical System 8 jTroubleshooting 9 j

This quick reference guide will assistyou in locating a desired topic or pro-cedure.• Bend the pages back to match theblack tab of the desired chapter num-ber with the black tab on the edge ateach table of contents page.•Refer to the sectional table of con-tents for the exact pages to locatethe specific topic required.

FJ180V

4-stroke air-cooled gasoline engine

All rights reserved. No parts of this publication may be reproduced, stored in a retrieval system, ortransmitted in any form or by any means, electronic mechanical photocopying, recording or otherwise,without the prior written permission of Quality Assurance Department/Consumer Products & MachineryCompany/Kawasaki Heavy Industries, Ltd., Japan.No liability can be accepted for any inaccuracies or omissions in this publication, although every possible

care has been taken to make it as complete and accurate as possible.The right is reserved to make changes at any time without prior notice and without incurring an obligation

to make such changes to products manufactured previously.All information contained in this publication is based on the latest product information available at the time

of publication. Illustrations and photographs in this publication are intended for reference use only and maynot depict actual model component parts.

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

LIST OF ABBREVIATIONSA 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 horsepowerBTDC before top dead center psi pound(s) per square inchC degree(s) Celsius r revolutionDC direct current rpm revolution(s) per minuteF farad(s) TDC top dead centerF degree(s) Fahrenheit TIR total indicator readingft foot, feet V volt(s)g gram(s) W watt(s)h hour(s) ohm(s)L liter(s)

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 ofthe 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. Theblow-by gases are led to the breather chamber through the crankcase. Then, it is led to theair cleaner.Oil is separated from the gases while passing through the inside of the breather chamberfrom the crankcase, and then returned back to the bottom of crankcase.

2. Exhaust Emission Control SystemThe 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) theremoval 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 thepurpose of emission control prior to its sale or delivery to the ultimate purchaser or while it is inuse, or (2) the use of the engine after such device or element of design has been removed orrendered 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 bytrained mechanics in a properly equipped shop.However, it contains enough detail and basic in-formation to make it useful to the owner who de-sires to perform his own basic maintenance andrepair work. A basic knowledge of mechanics,the proper use of tools, and workshop proce-dures must be understood in order to carry outmaintenance and repair satisfactorily. When-ever the owner has insufficient experience ordoubts as to his ability to do the work, all ad-justments, maintenance, and repair should becarried out only by qualified mechanics.In order to perform the work efficiently and

to avoid costly mistakes, read the text, thor-oughly familiarize yourself with the proceduresbefore starting work, and then do the work care-fully in a clean area. Whenever special tools orequipment are specified, do not use makeshifttools or equipment. Precision measurementscan only be made if the proper instruments areused, and the use of substitute tools may ad-versely affect safe operation.To get the longest life out of your engine:• Follow the Periodic Maintenance Chart in theService Manual.• Be alert for problems and non-scheduledmaintenance.• Use proper tools and genuine Kawasaki en-gine parts. Genuine parts provided as spareparts 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 newparts installed.

How to Use This ManualIn this manual, the product is divided into

its major systems and these systems make upthe manual’s chapters. The Quick ReferenceGuide shows you all of the product’s systemand assists in locating their chapters. Eachchapter in turn has its own comprehensive Ta-ble of Contents.For example, if you want ignition coil informa-

tion, use the Quick Reference Guide to locate

the Electrical System chapter. Then, use theTable of Contents on the first page of the chap-ter to find the Ignition coil section.Whenever you see these WARNING and

CAUTION symbols, heed their instructions!Always follow safe operating and maintenancepractices.

WARNINGThis warning symbol identifies specialinstructions or procedures which, if notcorrectly followed, could result in per-sonal injury, or loss of life.

CAUTIONThis caution symbol identifies specialinstructions or procedures which, if notstrictly observed, could result in dam-age to or destruction of equipment.

This manual contains four more symbols (inaddition toWARNING andCAUTION)which willhelp you distinguish different types of informa-tion.

NOTEThis note symbol indicates points of par-ticular interest for more efficient and con-venient operation.

• Indicates a procedural step or work to bedone.Indicates a procedural sub-step or how to dothe work of the procedural step it follows. Italso precedes the text of a WARNING, CAU-TION, or NOTE.Indicates a conditional step or what action totake 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 illustrationof the system components follows the Table ofContents. In these illustrations you will find theinstructions indicating which parts require spec-ified tightening torque, oil, grease or a lockingagent during assembly.

GENERAL INFORMATION 1-1

1General InformationTABLE OF CONTENTS

Before Servicing ........................................................................................................................ 1- 2Model Identification.................................................................................................................... 1- 4General Specifications............................................................................................................... 1- 5Torque and Locking Agent......................................................................................................... 1- 6

1-2 GENERAL INFORMATIONBefore Servicing

Before starting to service the engine, carefully read the applicable section to eliminate unnecessarywork. Photographs, diagrams, notes, cautions, warnings, and detailed descriptions have been in-cluded wherever necessary. Nevertheless, even a detailed account has limitations, a certain amountof 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, orother parts, will work as an abrasive and shorten the life of engine. For the same reason, beforeinstalling a new part, clean off any dust or metal filings.

(2) Tightening SequenceGenerally, 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 toavoid distortion of the part and/or causing gas or oil leakage. Conversely when loosening thebolts, nuts, or screws, first loosen all of them by about a quarter of a turn and then remove them.Where there is a tightening sequence indication in this Service Manual, the bolts, nuts, or screwsmust be tightened in the order and method indicated.

(3) TorqueWhen 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. Ifa part seems especially difficult to remove or install, stop and examine what may be causing theproblem. Whenever tapping is necessary, tap lightly using a wooden or plastic-faced mallet. Usean impact driver for screws (particularly for the removal of screws held by a locking agent) in orderto avoid damaging the heads.

(5) EdgesWatch for sharp edges, especially during major engine disassembly and assembly. Protect your

hands with gloves or a piece of thick cloth when lifting the engine or turning it over.(6) High-Flash Point Solvent

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

(7) Gasket, O-RingDo 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 itsouter or inner circumference so that it will go into place smoothly.

(9) Oil Seal and Grease SealReplace any oil or grease seals that were removed with new ones, as removal generally dam-

ages 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 ofseal, until the face of the seal is even with the end of the hole.

(10)Seal GuideA 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 temperaturegrease on the lips to reduce rubber to metal friction.

(11)LubricationEngine 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 (whicheveris more suitable) should be applied to any rubbing surface which has lost its lubricative film. Old

GENERAL INFORMATION 1-3Before Servicing

grease and dirty oil should be cleaned off. Deteriorated grease has lost its lubricative quality andmay contain abrasive foreign particles.Don’t use just any oil or grease. Some oils and greases in particular should be used only in

certain applications and may be harmful if used in an application for which they are not intended.This manual makes reference to molybdenum disulfide grease (MoS2) in the assembly of certainengine parts. Always check manufacturer recommendations before using such special lubricants.

(12)Electrical WiresAll 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 amountof one color and a lesser amount of a second color, so a two-color wire is identified by first theprimary color and then the secondary color. For example, a yellow wire with thin red stripes isreferred to as a "yellow/red" wire; it would be a "red/yellow" wire if the colors were reversed tomake red the main color.

(13)Replacement PartsWhen 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 conditionsor other damage. If there is any doubt as to the condition of them, replace them with new ones.

Abrasion Crack Hardening WarpBent Dent Scratch WearColor change Deterioration Seizure

(15)SpecificationsSpecification 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 dete-

riorated performance, replace the damaged parts.

1-4 GENERAL INFORMATIONModel Identification

GENERAL INFORMATION 1-5General Specifications

Items FJ180VType of engine Forced air-cooled, vertical shaft, OHV, 4-stroke gasoline engineBore 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 shaftCompression release Automatic compression releaseHigh idle speed 3200 rpmIgnition system Flywheel magneto with CDIRFI Per Canada and U.S.A. requirementsStarting system Recoil starterSpark plug NGK BPR5ESCarburetor Float type, fixed main jetAir cleaner Dual stage element, dry typeGovernor Flyweight all speed governorLubrication system Pressure feed by positive displacement pump

Oil capacity(when engine iscompletely dry)

0.65 L (0.69 US-qt)

Cooling system Forced air cooling by fanDimensions (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.

1-6 GENERAL INFORMATIONTorque and Locking Agent

The following tables list the tightening torque for the major fasteners, and the parts requiring use ofa 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.

TorqueFastener

N·m kgf·m ft·lbRemarks

Fuel System:Throttle Valve Screw 0.7 0.07 6 in·lbMain Jet 1.1 0.11 9.7 in·lbGovernor Arm Clamp Nut 7.8 0.80 69 in·lbPriming Nut 1.2 0.12 11 in·lbFuel Tank Cover Bolts 6.9 0.70 61 in·lbTank Drain Bolt 6.9 0.70 61 in·lbFloat Chamber Mounting Bolt 5.4 0.55 48 in·lbDrain 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 =SValve Clearance Lock Screws 6.9 0.70 61 in·lbConnecting Rod Big End 5.9 0.60 52 in·lb =OCap Bolts

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

Lubrication System:Oil Drain Plug 22 2.2 16 in·lbOil 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 31Recoil Starter Mounting Bolts 6.9 0.70 61 in·lbRecoil Starter Set Screw 1.0 0.10 8.9 in·lbSpark Plug 22 2.2 16Brake Lever Assembly Mounting Bolt 6.9 0.70 61 in·lbKill Switch Bolt 1.5 0.15 13 in·lbBrake Arm Mounting Bolt 9.3 0.95 82 in·lb

GENERAL INFORMATION 1-7Torque and Locking Agent

The table below, relating tightening torque to thread diameter, lists the basic torque for the bolts andnuts. Use this table for only the bolts and nuts which do not require a specific torque value. All of thevalues are for use with dry solvent-cleaned threads.

Basic Torque for General FastenersThreads dia Torque

(mm) N·m kgf·m ft·lb4 2.0 0.20 17 in·lb5 3.4 0.35 30 in·lb6 5.9 0.60 52 in·lb8 15 1.5 11

PERIODIC MAINTENANCE 2-1

2

Periodic MaintenanceTABLE OF CONTENTS

Periodic Maintenance Chart ...................................................................................................... 2- 2Specifications ............................................................................................................................ 2- 3Special Tools ............................................................................................................................. 2- 4Periodic Maintenance Procedures............................................................................................. 2- 5Fuel System............................................................................................................................ 2- 5High Idle Speed Adjustment ................................................................................................ 2- 5Fuel System Cleanliness Inspection .................................................................................... 2- 5Fuel Filter Inspection............................................................................................................ 2- 6Air Element Removal ........................................................................................................... 2- 6Air Element Installation ........................................................................................................ 2- 7Air Element Cleaning and Inspection................................................................................... 2- 7Air Cleaner Housing (Case and Body) Inspection ............................................................... 2- 8

Engine Top End ...................................................................................................................... 2- 8Cylinder Head Cleaning and Inspection............................................................................... 2- 8Valve Clearance Inspection ................................................................................................. 2- 8Valve Clearance Adjustment................................................................................................ 2- 9Valve Seat Inspection .......................................................................................................... 2- 9Valve Seat Repair ................................................................................................................ 2-10

Lubrication System ................................................................................................................. 2-13Oil Level Inspection.............................................................................................................. 2-13Oil Change ........................................................................................................................... 2-13

Electrical System .................................................................................................................... 2-14Spark Plug Cleaning and Inspection.................................................................................... 2-14Spark Plug Gap Inspection .................................................................................................. 2-14

2-2 PERIODIC MAINTENANCEPeriodic Maintenance Chart

To ensure satisfactory operation over an extended period of time, any engine requires normal main-tenance regular intervals. The Periodic Maintenance Chart below shows periodic inspection andmaintenance items and suitable intervals. The bullet mark (•) designates that the corresponding itemshould 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.

OPERATION INTERVALDaily First 8

hr.Every25 hr.

Every50 hr.

Every100 hr.

Every200 hr.

Every300 hr.

Check or clean air intake screen •Check and add engine oil •Check for fuel and oil leakage •Check for loose or lost nuts andscrews •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 cylinderand 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 EngineDealer for service, unless you have the proper equipment and mechanical proficiency.

PERIODIC MAINTENANCE 2-3Specifications

Item StandardFuel System

High idle speed 3200 r/min (rpm)

Air cleaner:Type Dual stage filtration systemPre-cleaner Foam elementSecond-stage cleaner Paper element

Engine Top EndValve clearance Intake Exhaust 0.10 ~ 0.15 mm (0.004 ~ 0.006 in.)Valve seating surface angle Intake Exhaust 45Valve seating surface width Intake Exhaust 0.6 ~ 0.9 mm (0.024 ~ 0.035 in.)

Lubrication SystemEngine oil:Type SF, SG, SH or SJ classViscosity SAE30, SAE10W-30Capacity [When engine is completely dry]

0.65 L (0.69 US-qt)Level Operating range (grid area) on dipstick

Electrical SystemSpark plug gap 0.75 mm (0.030 in.)

2-4 PERIODIC MAINTENANCESpecial Tools

Valve Seat Cutter, 45 - �27.5: 57001–1114



Valve Seat Cutter Holder Bar: 57001–1128

Valve Seat Cutter Holder - �6.0: 57001–1360

PERIODIC MAINTENANCE 2-5Periodic Maintenance Procedures

Fuel SystemHigh Idle Speed Adjustment

CAUTIONDo not adjust high idle speed with the air cleanerremoved.

•Start and warm up the engine throughly.

WARNINGAlways 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 tomove the control panel assembly.•Carefully move the control panel assembly right or left toobtain the specified high idle speed.

High Idle Speed3200 rpm

•Tighten the Mounting bolts.Fuel System Cleanliness Inspection

WARNINGGasoline is extremely flammable and can be ex-plosive under certain conditions. Turn the engineswitch stop position. Do not smoke. Make sure thearea is well-ventilated and free from any source offlame or sparks, this includes any appliance with apilot 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 checkto 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 fueltank (see Fuel System chapter).

2-6 PERIODIC MAINTENANCEPeriodic 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. Replacethe 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]


Air Element Installation• Install:Foam ElementPaper Element• Install the hollow [A] of the air cleaner case and projection[B] of the air cleaner body are fitting.

•Move the holders [A].

Air Element Cleaning and InspectionNOTE

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

WARNINGBecause of the danger of highly flammable liquids,do not use gasoline or a low flash-point solvent toclean 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 installingit.

• Clean the paper element [A] by tapping it gently on a flatsurface to remove dust. If the element is very dirty, re-place it with a new one.

CAUTIONDo not use compressed air to clean the paper ele-ment. Do not oil the paper or foam element.


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. Thehousing must seal well and permit only filtered air to reachthe carburetor.If the housing is damaged, it must be replaced.• Check that no foreign material is obstructing the air pas-sage.

Engine Top EndCylinder Head Cleaning and Inspection•Remove the cylinder head (see Engine Top End chapter).• Scrape the carbon deposits from the head and exhaustport with a suitable tool [A].• To avoid gouging, use scrapers that are made of a mate-rial that will not cause damage.• Clean the head in a bath of high flash-point solvent anddry it with compressed air.

WARNINGClean 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 alow flash-point solvent to clean the cylinder head.A fire or explosion could result.

•Straight edge [A] across the mating surface of the head atseveral different points, and measure warp by inserting athickness 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 isbadly damaged.

Cylinder Head WarpService 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 usinga 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

NOTEValve clearance must be checked when the engine iscold (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.


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

Valve Clearance (when cold)Intake, Exhaust 0.10 ~ 0.15 mm (0.004 ~ 0.006in.)

Valve Clearance Adjustment•Since valve repairs change the valve clearance, adjustthe valve clearance to the specification.• Assemble the cylinder head and install the cylinder headassembly on the block (see Engine Top End chapter).• Turn the crankshaft to the proper direction until the pistonis at TDC of the compression stroke (described above).• Loosen the lock screws [A] and valve clearance adjustingnuts [B].• Insert a 0.10 mm (0.004 in.) thickness gauge [C] betweenthe rocker arm and valve stem, and tighten the adjustingnut until the thickness gauge begins to bind between therocker arm and valve stem end. Use a sweeping motionwith the thickness gauge while making this adjustment.

Valve Clearance (when cold)Intake, Exhaust 0.10 ~ 0.15 mm (0.004 ~ 0.006in.)

•Holding the adjusting nut with a wrench, tighten the lockscrew 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 ifnecessary.

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 recondition-ing, replace the cylinder head.• Pitted or worn valve seats can be refaced. Lap the valvesto 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 thevalve head. It must be the correct width [A] and even allthe way around.


NOTEThe valve stem and guide must be in good condition orthis check will not be valid.

Good [A]Too wide [B]Too narrow [C]Uneven [D]If the valve seating pattern is not correct, repair the seat.

Valve Seating Surface Width (STD)Inlet, Exhaust 0.6 ~ 0.9 mm (0.024 ~ 0.035 in.)

Valve Seat Repair• Follow the manufacturer’s instructions for use of valveseat cutters.

Special ToolsIntake Valve:Seat Cutter 45 - �27.5 : 57001-1114Outside Cutter 32 - �28.0 : 57001-1119Exhaust Valve:Seat Cutter 45 - �27.5 : 57001-1114Outside Cutter 32 - �25.0 : 57001-1118Valve Seat Cutter Holder-�6.0 : 57001-1360Valve Seat Cutter Holder Bar : 57001-1128If the manufacturer’s instructions are not available, usethe following procedure.

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 pur-poses.

2. Do not drop or hit the valve seat cutter, or the diamondparticles may fall off.

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

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

4. Setting the valve seat cutter holder [A] in position, op-erate the cutter [B] with one hand [C]. Do not apply toomuch force to the diamond portion.

NOTEPrior to grinding, apply oil to the cutter, and during theoperation wash off any ground particles sticking to thecutter with washing oil.

5. After use wash the cutter with washing oil and apply athin layer of engine oil before storing.


Marks Stamped on the Cutter:The marks stamped on the back of the cutter represent thefollowing.1 Cutter number, selected from 1 to 1230 Cutter angle [A]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 withmachinist’s dye.•Measure the seat width [A]. If it is more than the STDwidth, the seating surface should be refaced.• If the valve seating pattern is not correct, repair the seat.•Coat the seat with machinist’s dye.• Fit a 45 seat cutter [A] to the holder and slide it into thevalve guide.Resurface the valve seat with a 45 cutter, removing onlyenough material to produce a smooth and concentricseat.

CAUTIONDo not grind the seat too much. Overgrinding willreduce valve clearance by sinking the valve into thehead. If the valve sinks too far into the head, it willbe impossible to adjust the clearance, and the cylin-der head must be replaced. Do not turn the cuttercounterclockwise or drop it against the seat, or itwill be dulled.


•Use a 32 seat cutter [A] to narrow the seat width to theSTD width.Turn the seat cutter one turn at a timewhile pressing downvery lightly. Check the seat width after each turn.

CAUTIONThe 32 cutter removes material very quickly.Check the seat width frequently to prevent overgrinding.

NOTEKeep the seat width as close as possible to the STDwidth.

•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 thevalve, and snap it closed against the seat several times.The valve surface should show good contact all the wayaround. Be sure the valve seat is centered on the valveface. The position of the valve in the seat is evident afterlapping the valve.If the seat does not make proper contact, lap the valveinto 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 theseat.• Lift the valve slightly from the seat every 8 to 10 strokes,continue lapping operation until a uniform ring appearsaround entire surface of the valve face.

•When lapping is completed, wash all parts in solvent toremove lapping compound. Dry the parts thoroughly.• Note the position of the lapping mark on the valve face.The lapping mark should appear on or near the center ofthe valve face.•When the engine is assembled, be sure to adjust the valveclearances (see Valve Clearance Adjustment).


Lubrication SystemOil Level Inspection•Place the engine on a level surface.•Remove the oil filler cap [A] and wipe its dipstick [B] witha clean cloth.• Insert the dipstick into gauge hole [C] without screwing itin, 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 en-gine oil to bring oil level to the operating range.

CAUTIONDo not add more oil above the operating range. Ex-cess oil will cause a smoking condition.

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

NOTEIf the engine oil type and make are unknown, use anybrand of the specified oil to top up the level in preferenceto running the engine with the oil level low. Then at yourearliest convenience, change the oil completely.

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

Oil Change•Change the oil after first 8 hours of operation. Thereafterchange 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.

WARNINGBe careful of hot oil when drained. It may be hotenough 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)


•Remove the oil filler cap and pour in the specified typeand amount of oil.

Engine Oil :Type: SF, SG, SH or SJ ClassViscosity: SAE30, SAE10W-30Capacity: [When engine is completely dry]

0.65 L (0.69 US-qt)

Electrical SystemSpark 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 theplug using a high flash-point solvent and a wire brush orother suitable tool.If the spark plug electrodes are corroded or damaged,or if the insulator is cracked, replace the plug. Use thestandard spark plug or its equivalent.Insulator [A]Center Electrode [B]Plug Gap [C]Side Electrode [D]

Spark Plug Gap Inspection•Measure the gap with a wire-type thickness gauge.If the gap is incorrect, carefully bend the side electrodewith a suitable tool to obtain the correct gap.

Spark Plug GapStandard: 0.75 mm (0.030 in.)

FUEL SYSTEM 3-1

3

Fuel SystemTABLE OF CONTENTS

Exploded View........................................................................................................................... 3- 2Specifications ............................................................................................................................ 3- 6Governor Link Mechanism......................................................................................................... 3- 7

Control Panel Assembly Removal ....................................................................................... 3- 7Control Panel Assembly Installation .................................................................................... 3- 7Governor Arm Removal ....................................................................................................... 3- 7Governor Arm Installation .................................................................................................... 3- 8Governor Assembly Inspection and Removal...................................................................... 3- 8Governor Assembly Installation ........................................................................................... 3- 9Governor Shaft Removal ..................................................................................................... 3- 9Governor Shaft Installation .................................................................................................. 3- 9

Carburetor ................................................................................................................................. 3-10Fuel and Air Flow ................................................................................................................. 3-10High Idle Speed Adjustment ................................................................................................ 3-11High Altitude Operation........................................................................................................ 3-11Main Jet Replacement ......................................................................................................... 3-11Fuel System Cleanliness Inspection .................................................................................... 3-12Carburetor Removal............................................................................................................. 3-12Carburetor Installation.......................................................................................................... 3-12Carburetor Disassembly/Assembly ..................................................................................... 3-13Carburetor Cleaning............................................................................................................. 3-14Carburetor Inspection .......................................................................................................... 3-15

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

Intake Manifold .......................................................................................................................... 3-17Intake Manifold Removal ..................................................................................................... 3-17Intake Manifold Installation .................................................................................................. 3-17Intake Manifold Inspection ................................................................................................... 3-17

Fuel Tank................................................................................................................................... 3-18Fuel Tank Removal .............................................................................................................. 3-18Fuel Tank Installation ........................................................................................................... 3-18Fuel Tank Cleaning .............................................................................................................. 3-19

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

Air Cleaner................................................................................................................................. 3-21Element Removal ................................................................................................................ 3-21Element Installation.............................................................................................................. 3-21Element Cleaning and Inspection ........................................................................................ 3-21Cleaner Body Removal ....................................................................................................... 3-21Cleaner Body Installation ..................................................................................................... 3-21Housing (Case and Body) Inspection .................................................................................. 3-22

3-2 FUEL SYSTEMExploded View

FUEL SYSTEM 3-3Exploded View

TorqueNo. Fastener N·m kgf·m ft·lb Remarks1 Govenor Arm Clamp Nut 7.8 0.80 69 in·lb2 Fuel Tank Cover Bolts 6.9 0.70 61 in·lb3 Tank Drain Bolt 6.9 0.70 61 in·lb

3-4 FUEL SYSTEMExploded View

FUEL SYSTEM 3-5Exploded View

TorqueNo. Fastener N·m kgf·m ft·lb Remarks1 Priming Nut 1.2 0.12 11 in·lb2 Throttle Valve Screw 0.7 0.07 6 in·lb3 Main Jet 1.1 0.11 9.7 in·lb4 Float Chamber Mounting Bolt 5.4 0.55 48 in·lb5 Drain Screw 4.2 0.43 37 in·lb

3-6 FUEL SYSTEMSpecifications

StandardItem

FJ180VCaburetor Specification:Make/ type Walbro LMJ-17AThrottle 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) 2 3/4(Idle mixture screw turns out)

Float level Float parallel to carburetor bodyHigh idle speed 3200 r/min (rpm)

Air Cleaner:Type Dual stage filtration systemPre-cleaner Foam elementSecond-stage cleaner Paper element

Fuel:Fuel requirement Unleaded regular grade gasoline

Governor:Type Flyweight all speed governor

FUEL SYSTEM 3-7Governor Link Mechanism

Control Panel Assembly Removal•Remove:Air Cleaner (see Cleaner Body Removal)Recoil Starter (see Electrical System chapter)Fuel Tank (see Fuel Tank Removal)Control Panel Mounting Bolts [A]

•Remove the control panel [B] unhooking the governorspring [A] end loop at the panel bracket.

Control Panel Assembly InstallationIf 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 clearthe throttle link rod lower end [D].

3-8 FUEL SYSTEMGovernor 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 throttlelever [E] toward each other.• Loosen the clamp nut [F] on the governor arm enough tomove the governor shaft.• Turn the top end of the governor arm counterclockwise[G] to fully open the carburetor throttle valve and hold itthere.• Turn the governor shaft counterclockwise, fully turn theshaft to end of its travel.There should be no gap between the governor arm andthe 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/Crankshaftchapter).• Visually check the governor assembly as built in thecrankcase cover for damage or wear.

CAUTIONDo not remove the governor assembly unless theparts are to be replaced. The parts cannot bereused once they are removed.

•When removing the governor gear assembly [A] for re-placing, use two screw drivers [B] of an appropriate size.

CAUTIONProtect the gasket-mount surface of the crankcasecover when removing the governor assembly withthe screw drivers.

FUEL SYSTEM 3-9Governor Link Mechanism

Governor Assembly Installation• Instal the sleeve [A] on the governor assembly [B].

CAUTIONFirst install the sleeve. The sleeve cannot be in-stalled after the governor gear assembly has beeninstalled.

•To install, first place the thrust washer [C] on the boss ofthe shaft [D]. Then, install the governor assembly (withthe sleeve attached) on the shaft so that step [E] is fittedsecurely in groove [F].• After installing the assembly, turn the governor by handto make sure that the governor weight [G] and the sleevemove 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)

•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 operatingrange.

3-10 FUEL SYSTEMCarburetor

Fuel and Air FlowThe main system of the carburetor consists of the main jet

[A], main nozzle [B], and the main air passage [C] (main airjet [D]). The main system meters fuel to the engine duringmoderate to high load conditions. Fuel flows through themain jet and into the main nozzle, where it is joined by airfrom the main air passage (main air jet). The resulting mix-ture flows out the end of the main nozzle into the carburetorbore, where it is atomized by the high speed air flow, andcarried 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 thebypass holes [I]. The pilot systemmeters the fuel/air mixturewhile the engine is idling and running under a light load.Under these conditions there is very little air flow throughthe carburetor bore, so little that it is not enough to draw fuelthrough the main system of the carburetor and atomize it.Instead, the fuel is drawn through the pilot system, since thenearly closed throttle valve [J] causes high speed air flowpast the pilot outlet and bypass holes (even at low enginespeed).Fuel flow in the pilot system is metered by the pilot jet. Air

for better atomization is admitted via the pilot air jet in themouth of the carburetor. The fuel/air mixture passes intothe bore of the carburetor side stream of the throttle valvethrough the bypass holes and pilot outlet. While the throt-tle valve is almost closed, it covers the small bypass holesopening into the bore from the pilot system. As the throttlevalve begins to open, it uncovers the bypass holes, allow-ing more fuel/air mixture to flow. The extra flow is neededbecause the engine starts to run faster as the throttle isopened. The pilot screw controls the amount of fuel/airmixture allowed through the pilot outlet, but does not me-ter the bypass holes. A moderate amount of air comes inaround the throttle valve at idle, so adjusting the pilot screwchanges the fuel/air ratio. Turning the pilot screw (Idle mix-ture screw) out (Counterclockwise) enriches the mixture;turning it in (clockwise) leans the mixture.Main Fuel Flow �

Pilot Fuel Flow �

FUEL SYSTEM 3-11Carburetor

High Idle Speed AdjustmentRefer to High Idle Speed Adjustment in the Periodic Main-tenance Chapter (2nd chapter).

High Altitude OperationAt high altitude, the standard carburetor air-fuel mixture

will be excessively rich. Performance will decrease, andfuel consumption will increase. High altitude performancecan be improved by installing a smaller diameter main jet inthe carburetor and correct high idle speed.

NOTEThe main jet high altitude kits are available if the equip-ment is to be used in the high altitudes. The main jetnumbers are stamped on ends of the main jets.

High Altitude Main Jet

Main Jet No.

Altitude FJ180V

0 � 1 000 m (0 � 3 000 ft) 92063–7048

1 000 � 2 000 m (3 000 � 6 000 ft) 92063–7049

2 000 m (6 000 ft) and higher 92063–7050

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 unscrewingthe drain screw [B] at the bottom of the float chamber.•Remove the carburetor (see Carburetor Removal).• Unscrew the float chamber mounting bolt [C] and take offthe 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 CarburetorDisassembly 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 PumpInstallation).


• Install the primer pipe [A] and drain screw as shown.90 � 100 [B]

Fuel System Cleanliness InspectionRefer to Fuel System Cleanliness Inspection in the Peri-odic Maintenance Chapter (2nd chapter).

Carburetor RemovalWARNING

Gasoline is extremely flammable and can be ex-plosive under certain conditions. Turn the engineswitch stop position. Do not smoke. Make sure thearea is well- ventilated and free from any source offlame or sparks, this includes any appliance with apilot 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 unscrewingthe 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 nosepliers.

Carburetor Installation•Clean the mating surfaces of the carburetor and intakemanifold, and fit the new gaskets.• Take care not to bend the throttle during installation. Makesure the link spring around the throttle link rod is in placeand that it pulls the governor arm and carburetor throttleshaft lever toward each other.• Adjust:High Idle Speed


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, mark the out side of throttle valve forassembling them.•Replace the pilot screw in accordance with the followingprocedure if necessary.Carefully mark the position of the pilot screw limiter onthe carburetor body so that it can be installed and set toits original position later.Remove the limiter. Be careful not to turn pilot screw atthis point.Turn the pilot screw clockwise and count the number ofturns 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 gentlyseated. Then open the screw the same number of turnsas recorded prior to removal.Align the limiter with the mark on the carburetor body toinstall, taking care not to turn the pilot screw.• Install the throttle valve on the shaft as the out side markof them facing out side.•Drive the float pin into the carburetor body from the limiterside.• Assemble carburetor parts with recommended tighteningtorque (see Exploded View).

1. Throttle Valve Screw2. Throttle Valve3. Throttle Shaft4. Seal5. Screw6. Spring7. Limiter8. Spring9. Main Nozzle10. Main Jet11. Float12. Needle Jet13. Float Pin14. Gasket15. Float Chamber16. Gasket17. Float Chamber Mounting Bolt18. Drain Screw19. Primer Pipe


Carburetor CleaningWARNING

Clean the carburetor in a well-ventilated area, andtake care that there is no sparks or flame anywherenear the working area, this includes any appliancewith a pilot light. Because of the danger of highlyflammable liquids, do not use gasoline or low flash-point solvents to clean the carburetor.

CAUTIONDo not use compressed air on an assembled carbu-retor, or the float may be crushed by the pressure.Remove as many rubber or plastic parts from thecarburetor as possible before cleaning the carbu-retor with a cleaning solution. This will prevent todamage or deterioration of the parts.The carburetor body has plastic parts that cannotbe removed. Do not use a strong carburetor clean-ing solution which could attack these parts instead,use a mild high flash-point cleaning solution safefor plastic parts.Do not use wire or any other hard instrument toclean carburetor parts, especially jets, as they maybe damaged.

•Disassemble the carburetor.• Immerse all the carburetor metal parts in a carburetorcleaning solution and clean them.• Rinse the parts in water and dry them with compressedair.• Do not use rags or paper to dry parts. Lint may plug thehole or passages.• Blow air through the holes and fuel passages with thecompressed air. All holes must be open.• Assemble the carburetor.


Carburetor InspectionWARNING

Gasoline is extremely flammable and can be explo-sive under certain. Turn the engine switch stopposition. Do not smoke. Make sure the area iswell ventilated and free from any source of flame orsparks this includes any appliance with a pilot light.

• Inspect the carburetor body for damage. Flange sealingsurfaces should be smooth and free of burrs and nicks.Replace the gasket if necessary.• Turn the throttle shaft to check that the throttle butterflyvalve move smoothly.If the valve do not move smoothly, replace the carburetorbody 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.

CAUTIONDo not push down on the float during float levelchecking.

•With the float [A] assembly installed onto the carburetorbody, hold the carburetor upside down at eye level. Gen-tly support the float with a finger and bring it down slowlyso that the float arm tab [B] touches the float valve [C]. Thefloat lower surface [D] should be parallel with the carbu-retor body mating surfaces.If the float position is not correct, replace the float with anew one.

• Inspect the float valve for excessive wear or damage. Thetip should be smooth, without any grooves, scratches, ortears. The rod at the other end of the needle should movesmoothly when push in and released.Good [A]Bad [B]If either the needle or the seat is worn or damaged, re-place the float assembly and carburetor body as a set.

3-16 FUEL SYSTEMPriming Pump

Priming Pump Removal•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 damages.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]

FUEL SYSTEM 3-17Intake Manifold

Intake Manifold Removal•Unscrew the intake manifold mounting bolts [A].• Remove the breather pipe [B] from the intake manifold.

Intake Manifold Installation•Replace the O-ring [A] with a new one.•Clean the mating surface of the carburetor and intakemanifold.

•Clean the mating surface of the carburetor and intakemanifold and install the new gasket [A] and intake mani-fold.

• Install the spacers [A] and tighten the intake manifoldmounting 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 ametal crack detection system (Visual color check: com-monly 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 SYSTEMFuel Tank

Fuel Tank Removal•Remove:Air Cleaner (see Cleaner Body Removal)Recoil Starter (see Electrical System chapter)Oil GaugeFuel 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 tankdrain.• 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 tankcover.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 betweenintake 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 SYSTEM 3-19Fuel Tank

Fuel Tank CleaningWARNING

Clean the fuel tank in a well-ventilated area, andtake care that there is no sparks or flame anywherenear the working area. Because of the danger ofhighly flammable liquids, do not use gasoline or lowflash-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 andshake the tank to remove dirt and fuel deposits.•Dry the fuel tank with compressed air.• Install the fuel tank (see Fuel Tank Installation).

3-20 FUEL SYSTEMFuel Filter

Fuel Filter InspectionRefer to Fuel Filter Inspection in the PeriodicMaintenance Chapter (2nd chapter).

FUEL SYSTEM 3-21Air Cleaner

Element RemovalRefer to Air Element Removal in the Periodic Mainte-nance Chapter (2nd chapter).

Element InstallationRefer to Air Element Instalation in the Periodic Mainte-nance Chapter (2nd chapter).

Element Cleaning and InspectionRefer to Air Element Cleaning and Inspection in the Peri-odic Maintenance Chapter (2nd chapter).

Cleaner Body Removal•Move the holders [A].

• Push up the latches [A] and remove the air cleaner case[B].•Remove:Paper ElementFoam Element

Cleaner Body Installation• Install:Foam ElementPaper Element• Install the hollow [A] of the air cleaner case and projection[B] of the air cleaner body are fitting.

3-22 FUEL SYSTEMAir Cleaner

•Move the holders [A].

Housing (Case and Body) InspectionRefer to Air Cleaner Housing (Case and Body) Inspectionin the Periodic Maintenance Chapter (2nd chapter).

COOLING SYSTEM 4-1

4

Cooling SystemTABLE OF CONTENTS

Exploded View........................................................................................................................... 4- 2Cooling Fan ............................................................................................................................... 4- 4

Cooling Fan Removal .......................................................................................................... 4- 4Cooling Fan Installation ....................................................................................................... 4- 4Cooling Fan Inspection ........................................................................................................ 4- 4

4-2 COOLING SYSTEMExploded View

COOLING SYSTEM 4-3Exploded View

TorqueNo. Fastener N·m kgf·m ft·lb Remarks1 Flywheel Bolt 42 4.3 312 Fuel Tank Cover Bolts 6.9 0.70 61 in·lb

4-4 COOLING SYSTEMCooling Fan

Cooling Fan RemovalRefer to Flywheel Removal in Electrical System Chapter.

Cooling Fan InstallationRefer to Flywheel Installation in Electrical System Chap-ter.

Cooling Fan Inspection•Visually inspect the blades [A] in the cooling fan [B].If they are any cracks, warps or damage, replace the cool-ing fan.If any mud or dust have stuck to the cooling fan, clean it.• Cooling fan is cleaned by washing in detergent and water.

CAUTIONDo not clean the cooling fan in oil solvent. It maybe damage by oil solvent.

ENGINE TOP END 5-1

5

Engine Top EndTABLE OF CONTENTS

Exploded View........................................................................................................................... 5- 2Specifications ............................................................................................................................ 5- 4Special Tools ............................................................................................................................. 5- 5Cylinder Head............................................................................................................................ 5- 6

Compression Measurement................................................................................................. 5- 6Cylinder Head Assembly Removal ...................................................................................... 5- 7Cylinder Head Assembly Installation ................................................................................... 5- 7Push Rod Removal .............................................................................................................. 5- 8Push Rod Installation........................................................................................................... 5- 8Push Rod Inspection............................................................................................................ 5- 8Valve Mechanism Removal/Installation ............................................................................... 5- 9Cleaning and Inspection ...................................................................................................... 5- 9Rocker Arm Inspection......................................................................................................... 5-10

Valves ........................................................................................................................................ 5-11Valve Clearance Inspection ................................................................................................. 5-11Valve Clearance Adjustment................................................................................................ 5-11Valve Seat Inspection .......................................................................................................... 5-11Valve Seat Repair ................................................................................................................ 5-11Valve Head Thickness ......................................................................................................... 5-11Valve Stem Runout .............................................................................................................. 5-11Valve Stem Diameter ........................................................................................................... 5-11Valve Guide Inside Diameter ............................................................................................... 5-12Valve Spring Inspection ....................................................................................................... 5-12Automatic Compression Release (ACR) Device Inspection ................................................ 5-12

Cylinder, Piston.......................................................................................................................... 5-13Piston Removal.................................................................................................................... 5-13Piston Installation................................................................................................................. 5-14Piston Cleaning.................................................................................................................... 5-16Piston Ring and Ring Groove Wear..................................................................................... 5-17Piston Ring End Gap ........................................................................................................... 5-17Piston Pin, Piston Pin Hole, and Connecting Rod Wear...................................................... 5-18Piston Diameter ................................................................................................................... 5-18Cylinder Inside Diameter...................................................................................................... 5-19

Muffler ....................................................................................................................................... 5-20Muffler Removal................................................................................................................... 5-20Muffler Installation................................................................................................................ 5-20Inspection............................................................................................................................. 5-20

5-2 ENGINE TOP ENDExploded View

ENGINE TOP END 5-3Exploded View

TorqueNo. Fastener N·m kgf·m ft·lb Remarks1 Cylinder Head Bolts 22 2.2 16 S2 Valve Clearance Lock Screws 6.9 0.70 61 in·lb3 Connecting Rod Big End Cap Bolts 5.9 0.60 52 in·lb O4 Rocker Arm Bolts 28 2.8 205 Spark Plug 22 2.2 166 Rocker Cover Mounting Bolts 5.9 0.60 52 in·lb7 Muffler Cover Self Tap Bolt (1) 6.9 0.70 61 in·lbO: Apply engine oil.S: Follow the specific tightening sequence.

5-4 ENGINE TOP ENDSpecifications

Item Service LimitCylinder 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, PistonPiston 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 mm (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 StandardValve clearance Intake, Exhaust 0.10 � 0.15 mm (0.004 � 0.006 in.)Valve seating surface angle Intake, Exhaust 45Valve 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 cylinderStandard 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.)

ENGINE TOP END 5-5Special Tools

Compression Gauge: 57001–221

Piston Ring Compression: 57001–1095

Piston Ring Compression Belt, �55 ~ �67:57001–1096

Compression Gauge Adapter M14 ×1.25 :57001–1159

5-6 ENGINE TOP ENDCylinder Head

Compression Measurement•Before measuring compression, do the following.Thoroughly warm up the engine so that engine oil be-tween the piston and cylinder wall will help seal compres-sion as it does during normal running.Stop the engine.• Disconnect the spark plug cap of and remove the sparkplug.• Attach the compression gauge assembly firmly into sparkplug 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 prox-imity to the plug hole. Keep the plug as far away aspossible from the plug hole.

•With the throttle fully open, turn engine over with the recoilstarter knob several times until the compression gaugestops rising, the compression is the highest reading ob-tainable.

Cylinder Compression (MIN)196 kPa (28.4 psi)

If the compression is higher than the specified value, thepiston rings, cylinder and valves are probably in good con-dition.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 cylinderhead.

2. Cylinder head gasket - use only the proper gasket. Theuse of a gasket of incorrect thickness will change thecompression.

3. Valve guides and piston rings - rapid carbon accumula-tion in the combustion chamber may be caused by wornvalve guides or worn piston oil ring. This may be indi-cated by white exhaust smoke.If cylinder compression is lower than the (MIN), check thefollowing:

1. Gas leakage around the cylinder head - replace thedamaged gasket and check and check the cylinder headwarp.

2. Condition of the valve seating.3. Valve clearance.4. Piston/cylinder wear, piston seizure.5. Piston ring, piston ring groove.

ENGINE TOP END 5-7Cylinder 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 Muffler Removal)Fan Housing (see Flywheel Removal)Intake Manifold and Carburetor (see Fuel System chap-ter)Spark Plug• Loosen the rocker cover mounting bolts [A] and removethe cover [B] and gasket.•When removing the cylinder head, set at T.D.C of Powerstroke in.

• Loosen the cylinder head bolts 1/4 turn in the sequenceshown.

CAUTIONIf the above procedure is not followed, the cylinderhead may be warped during removal.

•Repeat the sequence until all bolts are removed and liftoff the cylinder head assembly.

NOTEMark the push-rods so they can be installed in their orig-inal 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 tighteningsequence as shown.Torque - Cylinder Head Bolts: 22 N·m (2.2 kgf·m, 16 ft·lb)

CAUTIONA torque wrench must be used to assure propertorque. Improper tightening of the head bolts canresult 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.


Push Rod Removal•Set at T.D.C of power stroke in.• Remove the rocker cover (see Cylinder Head AssemblyRemoval).• Loosen the valve clearance adjusting nuts [A].•Move the rocker arms [B] to clear the push rod upperends.• Pull out the push rods.

NOTEMark the push rods so they can be installed in their orig-inal 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 slidingdown along inside wall [C] of the crankcase and positionthe push rod end onto the tappet.• Check that both intake and exhaust push rod on cylinderis at lowest position on the cam lobes [D], if not, turn theflywheel clockwise one turn (360 ) and reset at T.D.C ofpower stroke in.• Be sure the end of the push rods are correctly seated onthe tappets.• Tighten the valve clearance adjusting nuts (see PeriodicMaintenance chapter).• Check and adjust the valve clearance (see Periodic Main-tenance chapter).

Push Rod Inspection•Place the push rod in V blocks that are as far apart aspossible, and set a dial gauge [A] on the rod at a pointhalfway between the blocks. Turn the rod to measure therunout. The difference between highest and the lowestdial readings is the amount of runout.If the runout exceeds the service limit, replace the rod.

Rocker Arm Push Rod RunoutService Limit: 0.5 mm (0.02 in.)

ENGINE TOP END 5-9Cylinder Head

Valve Mechanism Removal/Installation•Remove the cylinder head assembly (see Cylinder HeadAssembly Removal).

NOTEWhen removing the valve mechanism parts, note theirposition so that they may be reinstalled in their originalposition during assembly.

•Remove:Valve Clearance Adjusting Nuts [A]Rocker Arms [B]

• Support the valve head in the combustion chamber witha suitable block.• To remove the collets [B], push down the valve retainer[A] with thumbs and remove the collets.•Remove the spring [C] and valve [D] .

NOTEValve 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 downin the guide.• Install the spring and valve retainer.• To install the collets, push down the valve retainer withthumbs and install the collets.Soak the valve clearance adjusting nuts and rocker armsin the engine oil.• Install the rocker arms by the valve clearance adjustscrews.• Adjust the valve clearance (see Periodic Maintenancechapter).

Cleaning and InspectionRefer to Cylinder Head Cleaning and Inspection in thePeriodic Maintenance Chapter (2nd chapter).


Rocker Arm Inspection•Clean and inspect the rocker arm where it touches thepush rod and valve stem.If the contact points [A] are worn or damaged, replace therocker arm.

ENGINE TOP END 5-11Valves

Valve Clearance InspectionRefer to Valve Clearance Inspection in the Periodic Main-tenance Chapter (2nd chapter).

Valve Clearance AdjustmentRefer to Valve Clearance Adjustment in the PeriodicMaintenance Chapter (2nd chapter).

Valve Seat InspectionRefer to Valve Seat Inspection in the Periodic Mainte-nance Chapter (2nd chapter).

Valve Seat RepairRefer to Valve Seat Repair in the Periodic MaintenanceChapter (2nd chapter).

Valve Head Thickness•Remove the valve (see Valve MechanismRemoval/Instal-lation).•Measure the thickness of the valve head.If the valve head thickness (valve margin) [A] is less thanthe service limit, replace the valve.

Valve Head ThicknessService Limit IN: 0.35 mm (0.014 in.)

EX: 0.36 mm (0.014 in.)

Valve Stem Runout•Support the valve in V blocks at each end of the stem.•Position a dial gauge perpendicular to the stem.• Turn the valve and read the variation on the dial gauge.If the stem runout is greater than service limit, replace thevalve.

Valve Stem RunoutService Limit (IN, EX): 0.05 mm (0.002 in.)

Valve Stem Diameter•Measure the diameter of the valve stem [A] in two di-rections at right angles, at four different positions on thestem.If any single measurement is less than the service limit,replace the valve.

Valve Stem DiameterService Limit (IN, EX): 5.93 mm (0.233 in.)

5-12 ENGINE TOP ENDValves

Valve Guide Inside Diameter•Use a small bore gauge or a micrometer to measure theinside diameter [A] of the valve guides [B] at three placesdown the length of the guides.If the measurement is more than the service limit, replacethe cylinder head with a new one.

Valve Guide Inside DiameterService Limit (IN, EX) : 6.08 mm (0.239 in.)

Valve Spring Inspection• Inspect the valve spring for pitting, cracks, rusting, andburns. Replace the spring if necessary.•Measure the free length [A] of the spring.If the measurement is less than the service limit, replacethe spring.

Valve Spring Free LengthService Limit: 33.5 mm (1.32 in.)

Automatic Compression Release (ACR) DeviceInspectionThe ACR reduces the compression of the cylinder in or-

der to facilitate the revolution of the crankshaft during thestarting 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 themovement of the exhaust valve [A] and the rocker arm [B].Immediately after the intake valve has closed, the rockerarm should push open the exhaust valve to attain a lift thatis greater. If the exhaust valve does not lift to that height,the ACR that is provided on the camshaft is faulty (seeCamshaft/Crankshaft chapter).

Exhaust Valve Lift Height Service Limit by ACRStandard: 0.9 mm (0.04 in.)

ENGINE TOP END 5-13Cylinder, 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/Crankshaftchapter).• Remove the camshaft (see Camshaft/Crankshaft chap-ter).• Turn the crankshaft to expose the connecting rod capbolts [A].• Remove the bolts and take off the connecting rod cap [B].

NOTENote the position of the connecting rod cap for rein-stalling the cap.

•Push the connecting rod end into the cylinder, and pull thepiston and connecting rod out of the cylinder.

•Remove one of the piston pin snap rings [A] with needlenose pliers [B].

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

5-14 ENGINE TOP ENDCylinder, Piston

•Carefully spread the ring opening with your thumbs andthen push up on the opposite side of the ring [A] to removeit.• Remove the 3-piece oil ring with your thumbs in the samemanner.

Piston Installation• Install the expander [A] in the piston oil ring groove so thatthe expander ends [B] touch together, never overlap.• Install the upper and lower steel rails. There is no UP orDown 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]Top Ring [B]Second Ring [C]

• Align the piston and rings with the piston ring end gap asshown.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]


•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 reverseside of the “K” mark [B] side the connecting rod, then in-sert the piston pin into the piston pin hole.

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

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

•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] toinsert 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 arrowmark [A] on the top of the piston is facing the flywheelside [B].


CAUTIONThe connecting rod and the connecting rod big endcap are machined at the factory in the assembledstate, so they must be replaced together as a set.

•Apply engine oil to the inner surface [A] of the connectingrod big end [B] and cap [C].• Set rod and cap aligning the mark [D] of rod to the mark ofcap, install the connecting rod big end cap in their originalposition 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 End Cap Bolts: 5.9 N·m (0.60

kgf·m, 52 in·lb)

• Install:Camshaft (see Camshaft/Crankshaft chapter)Crankcase Cover (see Camshaft/Crankshaft chapter)• Install the other removed parts.Piston Cleaning•Remove the piston and piston rings (see Piston Re-moval).

CAUTIONNever clean the piston head assembled. Carbonparticles 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 pistonhead. To avoid gouging, use scrapers that are made of amaterial that will not cause damage.• Clean the piston ring grooves [A] with a broken piston ringor other suitable tools.

CAUTIONBe careful not to widen the ring grooves. Damagedring grooves will require piston replacement.


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, replacethem.If the ring grooves are worn unevenly or damaged, re-place both the piston and piston rings.•Measure the clearance between the top and second ringsand their grooves using a thickness gauge [A].If the piston ring/groove clearance is greater than thespecified value, replace the piston.

Piston Ring/Groove ClearanceService Limit

Top, Second 0.17 mm (0.007 in.)

NOTEThe oil ring is a three piece assembled ring. It is difficultto measure the ring groove clearance and thickness,visually inspect only.

•Measure the piston ring thickness [A].Use a micrometer to measure at several points aroundthe rings.If any of the measurement are less than the service limit,replace the entire set of rings.

Piston Ring ThicknessService Limit

Top, Second 1.40 mm (0.055 in.)

NOTEWhen using new rings in a used piston, check for un-even groove wear. The rings should fit perfectly parallelto the groove sides. If not, replace the piston.

Piston Ring End Gap•Remove the piston rings.• Push each ring (one at a time) in the cylinder bore to apoint 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] witha thickness gauge.If the end gap of any ring is greater than the service limit,replace the entire set of rings.

Piston Ring End GapService Limit

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


Piston Pin, Piston Pin Hole, and Connecting RodWear•Remove the piston pin.•Measure the diameter of the piston pin with a micrometerat several points.If the outside diameter is less than service limit, replacethe piston pin.

Piston Pin Outside DiameterService Limit: 15.96 mm (0.628 in.)

•Measure the inside diameter [A] of the piston pin hole atseveral points on both side. Use a dial bore gauge.If the inside diameter is more than the service limit, re-place the piston.

Piston Pin Hole Inside DiameterService Limit: 16.08 mm (0.633 in.)

•Measure the inside diameter [A] of the small end of theconnecting rod at several points. Use a dial bore gauge.If the inside diameter is more than the service limit, re-place the connecting rod.

Connecting Rod Small End Inside DiameterService 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 rightangle to the direction of the piston pin hole.If the measurement is less than the service limit, replacethe piston.

Piston DiameterService Limit: 64.79 mm (2.551 in.)


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 thanthe service limit, replace the cylinder with a new one.10 mm (0.39 in.) [A]Middle [B]

Cylinder Inside DiameterStandard: 64.98 � 65.00 mm (2.558 � 2.559 in.)Service Limit: 65.10 mm (2.563 in.)

Cylinder Bore Out-of-RoundStandard: 0.01 mm (0.0004 in.)Service Limit: 0.056 mm (0.0022 in.)

5-20 ENGINE TOP ENDMuffler

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 themuffler when remov-ing the muffler assembly, or they could become damagedor distored.

Muffler Installation•Clean the gasket surface and install a new gasket eachtime 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 bestperformance and least noise.• Check the muffler for distortion or loose internal compo-nents. Loss of power could develop if loose internal muf-fler components restrict exhaust flow.

LUBRICATION SYSTEM 6-1

6

Lubrication SystemTABLE OF CONTENTS

Exploded View........................................................................................................................... 6- 2Engine Oil Flow Chart................................................................................................................ 6- 4Specifications ............................................................................................................................ 6- 5Engine Oil ................................................................................................................................. 6- 6

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

Lubrication System.................................................................................................................... 6- 7Oil Pump.................................................................................................................................... 6- 8

Oil Pump Removal ............................................................................................................... 6- 8Oil Pump Installation ............................................................................................................ 6- 8Oil Pump Inspection............................................................................................................. 6- 8

6-2 LUBRICATION SYSTEMExploded View

LUBRICATION SYSTEM 6-3Exploded View

TorqueNo. Fastener N·m kgf·m ft·lb Remarks1 Oil Drain Plug 22 2.2 162 Tank Drain Bolt 6.9 0.70 61 in·lb3 Oil Filter Cover Bolt 6.9 0.70 61 in·lbO: Apply engine oil.

6-4 LUBRICATION SYSTEMEngine Oil Flow Chart

LUBRICATION SYSTEM 6-5Specifications

Item StandardEngine Oil:Type SF, SG, SH or SJ classViscosity SAE30, SAE10W-30Capacity [When engine is completely dry] 0.65 L (0.69 US-qt)Level Operating range (grid area) on dipstick

Item Service LimitOil 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.)

6-6 LUBRICATION SYSTEMEngine Oil

CAUTIONEngine operation with insufficient, deteriorated,or contaminated engine oil will cause acceleratedwear 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 forceall air from the internal oil passages.

• Fill fresh engine oil to the specified level (see PeriodicMaintenance chapter).• Run the engine at slow speed 2 minutes.• Stop the engine and check the oil level.Oil Level InspectionRefer to Oil Level Inspection in the Periodic MaintenanceChapter (2nd chapter).

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

LUBRICATION SYSTEM 6-7Lubrication System

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

6-8 LUBRICATION SYSTEMOil 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 Camshaft/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 the 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 them.Check the clearance [A] between the inner and outer rotorwith a feeler gauge. Measure the clearance between thehigh point of the inner rotor and the high point of the outerrotor.If the measurement exceed the service limit, replace therotors as a set.

Inner and Outer Rotor ClearanceService Limit: 0.14 mm (0.006 in.)

•Measure the outside diameter [A] of the outer rotor with amicrometer at several points.If the rotor diameter is less than the service limit, replaceboth the inner and outer rotor.

Outer Rotor Outside DiameterService Limit: 22.940 mm(0.9031 in.)

•Measure the thickness [B] of the outer rotor with a mi-crometer at several pointsIf the rotor thickness is less than the service limit, replaceboth the inner and outer rotor.

Outer Rotor ThicknessService Limit: 11.960 mm (0.4709 in.)

LUBRICATION SYSTEM 6-9Oil Pump

•Measure the inside diameter [A] of the pump housing withan inside micrometer at several points.If the inside diameter is more than the service limit, re-place the crankcase.

Pump Housing Inside DiameterService Limit: 23.241 mm (0.915 in.)

•Measure the depth [B] of the pump housing with a depthmicrometer at several points.If any of measurement is more than the service limit, re-place the crankcase.

Pump Housing DepthService Limit: 12.220 mm (0.4811 in.)

CAMSHAFT/CRANKSHAFT 7-1

7

Camshaft/CrankshaftTABLE OF CONTENTS

Exploded View........................................................................................................................... 7- 2Specifications ............................................................................................................................ 7- 4Crankcase ................................................................................................................................. 7- 5

Crankcase Cover Removal .................................................................................................. 7- 5Crankcase Cover Installation ............................................................................................... 7- 5Inspection............................................................................................................................. 7- 6Cleaning............................................................................................................................... 7- 6

Breather..................................................................................................................................... 7- 7Breather Chamber Cover Removal ..................................................................................... 7- 8Breather Chamber Cover Installation .................................................................................. 7- 8Breather Valve Inspection .................................................................................................... 7- 8

Camshaft, Tappet ...................................................................................................................... 7- 9Camshaft, Tappet Removal.................................................................................................. 7- 9Camshaft, Tappet Installation............................................................................................... 7-10Camshaft Disassembly ........................................................................................................ 7-10Camshaft Assembly ............................................................................................................. 7-10Camshaft Inspection ............................................................................................................ 7-10Camshaft Bearing/Journal Wear.......................................................................................... 7-11

Crankshaft, Connecting Rod ..................................................................................................... 7-12Connecting Rod Removal .................................................................................................... 7-12Connecting Rod Installation ................................................................................................. 7-12Crankshaft Removal ............................................................................................................ 7-12Crankshaft Installation ......................................................................................................... 7-12Cleaning/Inspection ............................................................................................................ 7-12Connecting Rod Bend/Twist................................................................................................. 7-13Connecting Rod Big End/Crankpin Width Wear .................................................................. 7-13Connecting Rod Big End Bearing/Crankpin Wear ............................................................... 7-14Crankshaft Runout ............................................................................................................... 7-14Crankshaft Main Journal/Wear ............................................................................................ 7-15

7-2 CAMSHAFT/CRANKSHAFTExploded View

CAMSHAFT/CRANKSHAFT 7-3Exploded View

TorqueNo. Fastener N·m kgf·m ft·lb Remarks1 Crankcase Cover Bolts 8.8 0.90 78 in·lb S2 Connecting Rod Big End Cap Bolts 5.9 0.60 52 in·lb O3 Valve Clearance Lock Screws 6.9 0.70 61 in·lb4 Rocker Arm Bolts 28 2.8 20G: Apply grease.

O: Apply engine oil.

S: Follow the specific tightening sequence.

7-4 CAMSHAFT/CRANKSHAFTSpecifications

Item Service LimitCamshaft, 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

(0.008/3.94 in.)Connecting rod twist 0.2/100 mm

(0.008/3.94 in.)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.) TIRCrankshaft journal diameter PTO side 27.96 mm (1.101 in.)

Flywheel side 27.98 mm (1.102 in.)Crankcase:PTO shaft hole inside diameterCrankcase cover 27.98 mm (1.102 in.)

Crankshaft journal metal inside diameterCrankcase 27.98 mm (1.102 in.)

CAMSHAFT/CRANKSHAFT 7-5Crankcase

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 Chapter)•Unscrew the mounting bolts [A] and remove thecrankcase 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 gentlytap loose the crankcase cover.

Crankcase Cover Installation•Chip off the old gasket from the mating surfaces of thecrankcase and cover.•Using compressed air, blow out the oil passage in thecrankcase cover.•With a high flash-point solvent, clean off the mating sur-faces of the crankcase and cover, and wipe dry.

WARNINGClean the crankcase and cover in a well-ventilatedarea, and take care that there are no sparks or flameanywhere near the working area, this includes anyappliance with a pilot light. Do not use gasoline ora low flash-point solvent to clean parts. A fire orexplosion 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 thespace between the seal lip [C] and dust lip [D]. Press inthe new oil seal using a press or suitable tools until it isflush with flange surface [E]. Do not damage the seal lips.

•Check to see that the dowel pins [A] are in place on thecrankcase.• Install the gasket on the crankcase.

7-6 CAMSHAFT/CRANKSHAFTCrankcase

• Install the crankcase cover and tighten the crankcasecover 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 holeon the crankcase cover at several points. Replace thecrankcase cover if the inside diameter is more than theservice limit.

PTO Shaft Hole Inside DiameterService Limit: 27.98 mm (1.102 in.)

•Measure the inside diameter [A] of the crankshaft journalmetal on the crankcase at several points. Replace thecrankcase if the inside diameter is more than the servicelimit.

Crankshaft Journal Metal Inside DiameterService Limit: 27.98 mm (1.102 in.)

Cleaning•Remove:Camshaft and Tappets (see Camshaft, Tappet Removal)Connecting Rod and Piston (see Engine Top End chap-ter)Crankshaft (see Crankshaft Removal)• Clean up the crankcase and cover with a high flash-pointsolvent, and blow out any foreign particles that may be inthe pockets inside of the crankcase with compressed air.

WARNINGClean the crankcase and cover in a well-ventilatedarea, and take care that there is no sparks or flameanywhere near the working area. Because of thedanger of highly flammable liquids, do not usegasoline or low flash-point solvents.

CAMSHAFT/CRANKSHAFT 7-7Breather

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

7-8 CAMSHAFT/CRANKSHAFTBreather

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, andtighten the bolts.

Breather Valve Inspection•Remove the breather valve [A].• Inspect the breather valve [A] for breakage, hair crack ordistortion, replace it if necessary.• Inspect the valve seating surface. The surface should befree of nicks or burrs.• Be sure the drain hole on the breather chamber does notaccumulate with slugs before installing the breather valve.

CAMSHAFT/CRANKSHAFT 7-9Camshaft, 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 compressionstroke in.• Push down [A] the spring side of the rocker arm [B] andmove it to clear the push rod [C].•Remove the push rods and mark them so they can beinstalled in their original positions during assembly.

• 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 beinstalled in their original positions during assembly.

7-10 CAMSHAFT/CRANKSHAFTCamshaft, Tappet

Camshaft, Tappet Installation•Apply engine oil to the following.Tappet JournalCamshaft JournalCam Lobe SurfaceCamshaft Gear• Install the tappets in those old positions.• Align the punch marks [A] on the crankshaft gear and onthe camshaft gear.• Install the push rods (see Push Rod Installation).• Install the rocker arms on the push rods, and install thevalve 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 compression 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 swingssmoothly.

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/CRANKSHAFT 7-11Camshaft, Tappet

• Inspect the camshaft to make sure that its automatic com-pression Reduction (ACR) function operates smoothlyand 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] islower than the base [C], replace the ACR with a new one.When the weight is pulled entirely outward with your fin-ger, 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 eitherlobe, replace the camshaft.

Cam Lobe HeightService Limit (IN, EX) : 22.060 mm (0.8685 in.)

•Measure both camshaft journals at several points aroundthe journal circumference.If the journal diameter is less than the service limit, re-place the camshaft.

PTO Side Camshaft Journal DiameterService Limit: 7.77 mm (0.3059 in.)

Flywheel Side Camshaft Journal DiameterService Limit: 13.927 mm (0.5483 in.)

•Measure the inside diameter [A] of the camshaft hole onthe crankcase cover at several points.Replace the crankcase cover if the inside diameter ismore than the service limit.

Camshaft Hole Inside Diameter (Crankcase Cover)Service Limit: 11.060 mm (0.4354 in.)

7-12 CAMSHAFT/CRANKSHAFTCrankshaft, 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 Camshaft/Crankshaft chapter)Camshaft (see Camshaft/Crankshaft chapter)Connecting Rod (see Camshaft/Crankshaft chapter)• Pull the crankshaft [A] out of the crankcase. Tap gentlywith a wooden or plastic mallet if necessary to loosen thecrankshaft.

Crankshaft Installation•Clean up the crankshaft and crankcase thoroughly.• Check that the pivot arm for the governor is installed (seeFuel System chapter).• Pack some amount of high temperature grease into theoil seal on the crankcase.• Apply engine oil journal.• Install the crankshaft in the crankcase.Cleaning/Inspection•After removing, clean the connecting rod and crankshaftwith a high flash-point solvent and dry them with com-pressed air.• Inspect the teeth of the crankshaft gear for pitting, fatiguecracks, 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 dam-ages.Replace them if necessary.

CAMSHAFT/CRANKSHAFT 7-13Crankshaft, Connecting Rod

Connecting Rod Bend/Twist•Measure connecting rod bend.Select an arbor of the same diameter as the connectingrod big end, and insert the arbor through the connectingrod big end.Select an arbor of the same diameter as the piston pinand at least 100 mm long, and insert the arbor throughthe 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 heightgauge to measure the difference in the height of thesmall end arbor above the surface plate over a 100 mmlength to determine the amount of connecting rod bendby dial gauge [B].If connecting rod bend exceeds the service limit, the con-necting rod must be replaced.

Connecting Rod BendService Limit: 0.2/100 mm (0.008/3.94 in.)

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

Connecting Rod TwistService 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, replacethe connecting rod.

Connecting Rod Big End WidthService Limit: 23.44 mm (0.92 in.)

7-14 CAMSHAFT/CRANKSHAFTCrankshaft, Connecting Rod

•Measure the crankpin width [A] with a dial caliper.If the crankpin width is more than the service limit, replacethe crankshaft.

Crankpin WidthService 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 specifiedtorque (see Piston Installation in Engine Top End chap-ter).•Measure the inside diameter [A] of big end at severalpoints with a telescoping gauge or inside micrometer.If the inside diameter is more than the service limit, re-place the connecting rod with a new one.

Connecting Rod Big End Inside DiameterService Limit: 31.040 mm (1.222 in.)

•Measure the crankpin outside diameter [A].Use a micrometer to measure several points around thecrankpin circumference.If the crankpin diameter is less than the service limit, re-place the crankshaft with a new one.

Crankpin Outside DiameterService Limit: 30.97 mm (1.219 in.)

Crankshaft Runout•Measure the crankshaft runout.Set the crankshaft in a flywheel alignment jig [A] or on Vblocks gauge.Set a dial gauge [B] against both journals.Turn the crankshaft slowly to measure the runout. The dif-ference between the highest and lowest dial gauge read-ings (TIR) is the amount of runout.If the measurement exceeds the service limit, replace thecrankshaft.

Crankshaft RunoutService Limit: 0.05 mm (0.002 in.) TIR

CAMSHAFT/CRANKSHAFT 7-15Crankshaft, Connecting Rod

Crankshaft Main Journal/Wear•Measure both journals at several points around the jour-nal circumference.If the journal diameter is less than the service limit, re-place the crankshaft with a new one.

PTO Side Crankshaft Journal Diameter [A]Service Limit: 27.96 mm (1.101 in.)

Flywheel Side Crankshaft Journal Diameter [B]Service Limit: 27.98 mm (1.102 in.)

ELECTRICAL SYSTEM 8-1

8

Electrical SystemTABLE OF CONTENTS

Exploded View........................................................................................................................... 8- 2Specifications ............................................................................................................................ 8- 4Special Tools ............................................................................................................................. 8- 5Wiring Diagram ......................................................................................................................... 8- 6Precautions................................................................................................................................ 8- 7Charging, Ignition System ......................................................................................................... 8- 8

Flywheel Removal................................................................................................................ 8- 8Flywheel Installation............................................................................................................. 8- 9Circuit Composition.............................................................................................................. 8-11Action Principle ................................................................................................................... 8-11Cautions of handling and maintenance................................................................................ 8-12Ignition Coil Removal ........................................................................................................... 8-12Ignition Coil Installation ........................................................................................................ 8-12Ignition Coil Inspection......................................................................................................... 8-13Spark Plug Removal ............................................................................................................ 8-13Spark Plug Installation ......................................................................................................... 8-13Spark Plug Cleaning and Inspection.................................................................................... 8-13Spark Plug Gap Inspection .................................................................................................. 8-13

Starter System........................................................................................................................... 8-14Recoil Starter Removal ........................................................................................................ 8-14Recoil Starter Installation ..................................................................................................... 8-14Recoil Starter Disassembly.................................................................................................. 8-14Recoil Starter Assembly....................................................................................................... 8-15

Pad Brake.................................................................................................................................. 8-17Pad Brake Assembly Removal ............................................................................................ 8-17Pad Brake Assembly Installation ......................................................................................... 8-17Brake Switch Removal/Installation....................................................................................... 8-18

8-2 ELECTRICAL SYSTEMExploded View

ELECTRICAL SYSTEM 8-3Exploded View

TorqueNo. Fastener N·m kgf·m ft·lb Remarks1 Flywheel Bolt 42 4.3 312 Recoil Starter Set Screw 1.0 0.10 8.9 in·lb3 Spark Plug 22 2.2 164 Brake Arm Mounting Bolt 9.3 0.95 82 in·lb5 Fuel Tank Cover Bolts 6.9 0.70 61 in·lb6 Recoil Starter Mounting Bolts 6.9 0.70 61 in·lb7 Brake Lever Assembly Mounting Bolt 6.9 0.70 61 in·lb8 Kill Switch Bolt 1.5 0.15 13 in·lbDO: Degrease the taper.

8-4 ELECTRICAL SYSTEMSpecifications

Item Standard Service LimitIgnition System:Ignition coil:Primary winding resistance in the text – – –Secondary winding resistance in the text – – –

Spark Plug NGK BPR5ES – – –Plug gap 0.75 mm (0.030 in.) – – –

ELECTRICAL SYSTEM 8-5Special Tools

Hand Tester: 57001–1394 Bracket Holder: 57001–1536

8-6 ELECTRICAL SYSTEMWiring Diagram

ELECTRICAL SYSTEM 8-7Precautions

There are a number of important precautions that mustbe taken when servicing electrical systems. Learn and ob-serve all the rules below.The electrical parts should never be struck sharply, aswith a hammer, or allowed to fall on a hard surface. Sucha shock to the parts can damage them.Troubles may involve one or in some cases all items.Never replace a defective part without determining whatCAUSED the failure. If the failure was brought on bysome other item or items, they too must be repaired orreplaced, or the replacement part will soon fail again.Make sure all connectors in the circuit are clean and tight,and examine wires for signs of burning, fraying, etc. Poorwires and bad connections will affect electrical system op-eration.Measure coil and winding resistance when the part is cold(at room temperature).

Electrical Connectors:Female Connector [A]Male Connector [B]

8-8 ELECTRICAL SYSTEMCharging, Ignition System

Flywheel Removal•Remove:Air Cleaner (see Fuel System chapter)Recoil Starter (see Electrical System chapter)Fuel Tank (see Fuel System chapter)

• Hold the pulley [B] with a bracket holder [A], remove theflywheel bolt and washer.Special Tool - Bracket Holder: 57001–1536

•Remove the pulley.

• Loosen the fan housing bolts [A] and remove the fanhousing [B] and screen [C].• Remove the fan.

• Remove:Ignition Coil (see Ignition Coil Removal)• Remove the pad brake (see Pad Brake Removal).• Using a suitable flywheel puller [A], remove the flywheel[B].

CAUTIONAlways use flywheel puller.

ELECTRICAL SYSTEM 8-9Charging, Ignition System

•Remove:Woodruff Key [A]

Flywheel Installation•Using a cleaning fluid, clean off any oil or dirt on the fol-lowing portions and dry them with a clean cloth.Crankshaft Tapered Portion [A]Flywheel Tapered Portion [B]Degrease the flywheel taper, crankshaft taper, before as-sembring.• Fit the Woodruff key [C] securely in the slot in the crank-shaft before installing the flywheel.• Install the flywheel onto the crankshaft taper so that thewoodruff key fits in the key way in the hub of the flywheel.

• Install:Ignition Coil (see Ignition Coil Installation)Pad Brake (see Pad Brake Installation)• Install the fan [A] so that two positioning bosses [B] fitaround flywheel ignition magnet [C].• Install the fan housing and tighten the fan housing mount-ing screws.• Install the screen to the fan housing.

• The pulley [A] so that the project [B] fit into the recess [C]of the flywheel.


• Install the pulley [A] and washer [B].• Tighten the flywheel bolt [C].Torque - Flywheel Bolt: 42 N·m (4.3 kgf·m, 31 ft·lb)

• Install the washer [A] as shown.Flywheel Bolt [B]• Install the other removed parts.


Circuit Composition

Co: Ignition Coil CoreC: CondenserD1: DiodeD2: DiodeD3: Diode

E: Exciter CoilL1: Primary CoilL2: Secondary Coil

SCR: ThyristorSP: Spark Plug

Action Principle(1) Fundamental action1. Genarated positive direction voltage by rotor rotated in the exciter coil (E) flow the electrical currentthrough the diode (D1), and discharged to the condenser (C).

2. Generated opposite direction current flow to the thyristor (SCR) because of voltage had generatedin the exciter coil (E) also at the opposite direction.

3. If the voltage of opposite direction reaches to the trigger voltage of the thyristor (SCR), the thyris-tor (SCR) will be ON state, and voltage is charged by the condenser (C) discharge rapidly to theprimary coil (L1).

4. The primary voltage of several hundreds volt generate because of large electrical current flowsrapidly to the primary coil (L1), the primary voltage are pressure risen by the secondary coil (L2),and turn into the secondary voltage of several thousands volt, and spark generate to the spark plug(SP) of output side.

(2) Spark advance characteristic1. If the revolutions number rises, the opposite direction voltage of exciter coil (E) which the trigger po-sition of the thyristor (SCR) changes and spark advance because of voltage wave form will change.

2. Spark advance is controlled by spark advance characteristic control circuit in the figure.(3) Spark delay characteristic1. The trigger position of the thyristor (SCR) changes and spark delay by decreasing the voltage waveform applied to the thyristor (SCR) in the revolutions number set up in the spark delay characteristiccontrol circuit in the figure.

2. The start revolutions number of spark delay is controlled by spark delay characteristic control circuitin the figure.


Cautions of handling and maintenance(1) Do not near the magnet by the heat of fire.(2) Ignition timing is no adjustment because of it is fixed.(3) When carry out the spark test, pull the recoil starter knob with strong force. If the flywheel does

not turned more than the ignition revolutions, spark does not ignite.

Ignition Coil Removal•Remove:Fan (see Flywheel Removal)Spark Plug CapEarth Read Wire [A]Bolts [B]Ignition Coil [C]

Ignition Coil Installation• Install ignition coil [A] on crankcase and tighten bolt (1)first, then tighten bolt (2). While tightening bolts, adjustthe air gap [B] between the leg of ignition coil and themagnet to the specified gap value as shown.

Ignition Coil Air GapStandard: 0.2 � 0.4 mm (0.008 � 0.016 in.)

NOTEAbove procedure must be used to insure proper coil airgap is not too large.

• Install:Ignition Coil [A]Bolts [B]Earth Read Wire [C]•When installing the earth read wire, put earth read wirebetween second and third fin.


Ignition Coil Inspection•Remove the ignition coil (see Ignition Coil Removal).•Measure the winding resistance as follows.Set the hand tester to the R × 1 k range.Special Tool - Hand Tester: 57001–1394Make the measurements shown in the table.

Ignition Coil Winding Resistance

CAUTIONUse only Tester 57001–1394 with new battery atroom temperature for this test. A tester other thanthe Kawasaki Hand Tester should show differentreadings.If a megger or a meter with a large-capacity batteryis used, the ignition coil will be damaged.

If the tester does not read as specified, replace the coil.

Spark Plug Removal•Carefully pull the plug cap from the spark plug.•Remove the spark plug using a suitable plug wrench.Spark Plug Installation• Insert the spark plug vertically into the plug hole with theplug installed in the plug wrench.• Tighten the plug.Torque - Spark Plug: 22 N·m (2.2 kgf·m, 16 ft·lb)

•Fit the plug cap securely.• Pull up the spark plug cap lightly to make sure of the in-stallation of the spark plug cap.

Spark Plug Cleaning and InspectionRefer to Spark Plug Cleaning and Inspection in the Peri-odic Maintenance Chapter (2nd chapter).

Spark Plug Gap InspectionRefer to Spark Plug Gap Inspection in the Periodic Main-tenance Chapter (2nd chapter).

8-14 ELECTRICAL SYSTEMStarter System

Recoil Starter Removal•Remove:Recoil Starter Mounting Bolts [A]Recoil Starter [B]

Recoil Starter Installation• Install the recoil starter and tighten the mounting bolts.Torque - Recoil Starter Mounting Bolts: 6.9 N·m (0.70

kgf·m, 61 in·lb)

Recoil Starter Disassembly•Remove the recoil starter (see Recoil Starter Removal).• Pull the starter knob [A] 30 cm (1 ft), and clamp the rope[B] with the clip [D] so it can not wind back onto the reel[C].• Pry the knot [E] out of the starter knob and untie it.• Remove the starter knob from the rope.

WARNINGWear gloves to avoid injury for the remaining steps.

•While carefully holding the reel [A] and case [B], removethe clip.• Unwind the spring tension slowly.

NOTEDo not wedge the rope between the reel and case.

•Remove:Set Screw [A]Ratchet Guide [B]Friction Spring [C]Ratchets [D]Reel [E]

ELECTRICAL SYSTEM 8-15Starter System

WARNINGWhen removing the reel [A], be careful that the spi-ral spring [B] in the reel does not fly loose and causeinjury. The spring is under great pressure.

NOTEThere should be no spring tension on the reel whenremoving it. If tension is felt, push the reel back intoplace and gently “wiggle” it until the reel can be easilyremoved.

•Slowly lift the reel straight up out of the case [C].WARNING

Be careful that the spiral spring does not fly looseand cause injury. The spring is under great pres-sure.

If the spiral spring must be removed, hold the reel facingdownward in a suitable container and remove the spiralspring by tool.

Recoil Starter AssemblyWARNING

Wear gloves during the spiral spring installation toavoid injury. The spiral spring must be assembledwith great pressure.

•Apply grease the spiral spring.•Wind the rope clockwise [A] on the reel, and hold the ropeend [B] with tape.• Install the spiral spring by tool.

• Apply grease the shaft [A].• Put the reel with the notch [B] aligned with the spring innertongue [C].• At that time engage the spiral spring with the starter case.• Turn the reel clockwise until you feel the hang hook onthe catch.

8-16 ELECTRICAL SYSTEMStarter System

•Remove the tape.• Install:Ratchets [A]Friction Spring [B]

• Install the ratchet guide [A].• Tighten the set screw [B].Torque - Recoil Starter Set Screw: 1.0 N·m (0.10 kgf·m, 8.9

in·lb)

• Turn the reel two turns counterclockwise to preload thespiral spring.

•While holding the reel to keep it from unwinding, feed theend of the rope through the hole in the case.• Clip [A] the rope as shown to hold it.• Install the starter knob [B] and secure it with a knot [C].• Remove the clip to release the rope.

ELECTRICAL SYSTEM 8-17Pad Brake

Pad Brake Assembly Removal•Remove:Air Cleaner (see Fuel System chapter)Recoil Starter (see Electrical System chapter)Fuel Tank (see Fuel System chapter)Pulley (see Flywheel Removal)Fan Housing and Fan (see Flywheel Removal)

•Remove the brake lever assembly mounting bolt [A].• Remove the spring [B] from the lever assembly and re-move the lever assembly [C].•Remove the spring [B] and bolt [D].

• Remove the earth read wire from the ignition coil.• Remove the control panel assembly (see Fuel Systemchapter).• Remove the spring [A] from the brake panel assembly.•Remove the spring [A].•Remove the brake arm mounting bolt [B] and nut [C].•Remove the brake arm and brake panel.

CAUTIONMake sure that pad brake always stop engine within3 secondswhen pad brake is ON. If not, check brakeshoe and/or related parts for wear and damage. Re-place parts if necessary.

Pad Brake Assembly Installation• Install the brake arm [A], brake panel [B] and spring [C]as shown.• Install the brake arm mounting bolt and nut.Torque - Brake Arm Mounting Bolt: 9.3 N·m (0.95 kgf·m, 82

in·lb)

• Install the brake panel assembly and control panel as-sembly (see Fuel System chapter).• Install the earth read wire in the ignition coil (see IgnitionCoil Installation).

8-18 ELECTRICAL SYSTEMPad Brake

• Tighten the bolt [A].• Install the lever assembly [B].• Tighten the brake lever assembly mounting bolt [C].Torque - Brake Lever Assembly Mounting Bolt: 6.9 N·m

(0.70 kgf·m, 61 in·lb)Check the lever assembly move smoothly was installed.• Install the spring [D].• Install the other removed parts.• Adjust the high idle speed to the specifications (see Peri-odic Maintenance chapter).

Brake Switch Removal/Installation•Refer to the illustration shown for removal and installation.Nut [A]Washer [B]Earth Read Wire [C]Cover [D]Brake Panel Assembly [E]Insulator [F]Terminal [G]Kill Switch Bolt [H]Torque - Kill Switch Bolt: 1.5 N·m (0.15 kgf·m, 13 in·lb)

• Install the brake switch [A] so that face out as shown.

TROUBLESHOOTING 9-1

9

TroubleshootingTABLE OF CONTENTS

Engine Troubleshooting Guide .................................................................................................. 9- 2

9-2 TROUBLESHOOTINGEngine Troubleshooting Guide

If the engine malfunctions, check if the way the engine is used is correct. If engine malfunctionseven if engine is used correctly, systematically carry out troubleshooting starting with simple points.This chart describes typical troubleshooting procedures.It’s not necessary to disassemble carburetor, magneto or engine unless it has been found to be the

cause of the malfunction.

TROUBLESHOOTING 9-3Engine Troubleshooting Guide

9-4 TROUBLESHOOTINGEngine Troubleshooting Guide

TROUBLESHOOTING 9-5Engine Troubleshooting Guide

4-stroke air-cooled gasoline engine

Documents

Transcript of 4-stroke air-cooled gasoline engine