Kawasaki FH500V User Manual

Page 1

FH451V,FH500V,FH531V FH601V,FH641V,FH680V

FH721V

4–stroke air cooled v-twin gasoline engine

Service Manual

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

No liability can be accepted for any inaccuracies or omissions in this publication, although every possible care has been taken to make it as complete and accurate as possible.

The right is reserved to make changes at any time without prior notice and without incurring an obligation to make such changes to products manufactured previously.

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

Page 2

LIST OF ABBREVIATIONS

A ampere(s) lb pound(s) ABDC after bottom dead center m meter(s)

AC alternating current min minute(s) ATDC after top dead center N newton(s) BBDC before bottom dead center Pa pascal(s) BDC bottom dead center PS horsepower BTDC before top dead center psi pound(s) per square inch



C DC direct current rpm revolution(s) per minute F farad(s) TDC top dead center



F degree(s) Fahrenheit TIR total indicator reading ft foot, feet V volt(s) g gram(s) W watt(s) h hour(s) L liter(s)

degree(s) Celsius r revolution



ohm(s)

Read OWNER’S MANUAL before operating.

Page 3

EMISSION CONTROL INFORMATION

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

1. Crankcase Emission Control System A sealed-type crankcase emission control system is used to eliminate blow-by gases. The blow-by

gases are led to the breather chamber through the crankcase. Then, it is led to the air cleaner.

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

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

2. Exhaust Emission Control System

The exhaust emission control system applied to this engine consists of a carburetor and an ignition

system having optimum ignition timing characteristics.

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

economy with a suitable air cleaner and exhaust system.

TAMPERING WITH EMISSION CONTROL SYSTEM PROHIBITED

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

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

Carburetor and internal parts

•

Spark plugs

•

Magneto or electronic ignition system

•

Fuel ﬁlter element

•

Air cleaner elements

•

Crankcase

•

Cylinder heads

•

Breather chamber and internal parts

•

Intake pipe and tube

•

Page 4

Foreword

This manual is designed primarily for use by trained mechanics in a properly equipped shop. However, it contains enough detail and basic information to make it useful to the owner who desires to perform his own basic maintenance and repair work. A basic knowledge of mechanics, the proper use of tools, and workshop procedures must be understood in order to carry out maintenance and repair satisfactorily. Whenever the owner has insufﬁcient experience or doubts as to his ability to do the work, all adjustments, maintenance, and repair should be carried out only by qualiﬁed mechanics.

In order to perform the work efﬁciently and to avoid costly mistakes, read the text, thoroughly familiarize yourself with the procedures before starting work, and then do the work carefully in a clean area. Whenever special tools or equipment are speciﬁed, do not use makeshift tools or equipment. Precision measurements can only be made if the proper instruments are used, and the use of substitute tools may adversely affect safe operation.

To get the longest life out of your engine:

Follow the Periodic Maintenance Chart in the Service

•

Manual.

Be alert for problems and non-scheduled maintenance.

•

Use proper tools and genuine Kawasaki engine parts.

•

Genuine parts provided as spare parts are listed in the

Parts Catalog.

Follow the procedures in this manual carefully. Don’t

•

take shortcuts.

Remember to keep complete records of maintenance

•

and repair with dates and any new parts installed.

If you want spark plug information, for example, go to the Periodic Maintenance Chart ﬁrst. The chart tells you how frequently to clean and gap the plug. Next, use the Quick Reference Guide to locate the Electrical System chapter. Then, use the Tableof Contents on the ﬁrst page of the chapter to ﬁnd the Spark Plug section.

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

This warning symbol identiﬁes special instruc-

tions or procedures which, if not correctly fol-

lowed, could result in personal injury, or loss of

life.

CAUTION

This caution symbol identiﬁes special instruc-

tions or procedures which, if not strictly ob-

served, could result in damage to or destruction

of equipment.

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

NOTE



This note symbol indicates points of particular interest for more efﬁcient and convenient operation.

How to Use This Manual

In preparing this manual, we divided the product into its major systems. These systems became the manual’s chapters. All information for a particular system from adjustment through disassembly and inspection is located in a single chapter.

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

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

Indicates a procedural step or work to be done.

•



Indicates a procedural sub-step or how to do the work of the procedural step it follows. It also precedes the text of a WARNING, CAUTION, or NOTE. Indicates a conditionalsteporwhataction to take based on the results of the test or inspection in the procedural step or sub-step it follows.

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

Page 5

GENERAL INFORMATION 1-1

General Information

Table of Contents

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

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

General Speciﬁcations.......................................................................................................................................................1-6

Periodic Maintenance Chart...............................................................................................................................................1-7

Torque and Locking Agent.................................................................................................................................................1-9

Special Tools....................................................................................................................................................................1-13

Page 6

1-2 GENERAL INFORMATION

Before Servicing

Before starting to service the engine, carefully read the applicable section to eliminate unnecessary work. Photographs, diagrams, notes, cautions, warnings, and detailed descriptions have been included wherever necessary. Nevertheless, even a detailed account has limitations, a certain amount of basic knowledge is required for successful work.

Especially note the following:

(1) Dirt

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

(2) Battery Ground

Remove the ground (—) lead from the battery before performing any disassembly operations on the equipment. This prevents: (a) the possibility of accidentally turning the engine over while partially disassembled. (b) sparks at electrical connections which will occur when they are disconnected. (c) damage to electrical parts.

(3) Tightening Sequence

Generally, when installing a part with several bolts, nuts, or screws, start them all in their holes and tighten them to a snug ﬁt. Then tighten them evenly, in a staggered sequence. This is to avoid distortion of the part and/or causing gas or oil leakage. Conversely when loosening the bolts, nuts, or screws, ﬁrst loosen all of them by about a quarter of a turn and then remove them. Where there is a tightening sequence indication in this Service Manual, the bolts, nuts, or screws must be tightened in the order and method indicated.

(4) Torque

When torque values are given in this Service Manual, use them. Either too little or too much torque may lead to serious damage. Use a good quality, reliable torque wrench.

(5) Force

Common sense should dictate how much force is necessary in assembly and disassembly. If a part seems especially difﬁcult to remove or install, stop and examine what may be causing the problem. Whenever tapping is necessary, tap lightly using a wooden or plastic-faced mallet. Use an impact driver for screws (particularly for the removal of screws held by a locking agent) in order to avoid damaging the heads.

(6) Edges

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

(7) High-Flash Point Solvent

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

(8) Gasket, O-Ring

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

(9) Liquid Gasket, Non-Permanent Locking Agent

Follow manufacturer’s directions for cleaning and preparing surfaces where these compounds will be used. Apply sparingly. Excessive amounts may block engine oil passages and cause serious damage. An example of a nonpermanent locking agent commonly available in North America is Loctite Lock’n Seal (Blue).

(10) Press

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

(11) Ball Bearing

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

(12) Oil Seal and Grease Seal

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

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

(13) Seal Guide

A seal guide is required for certain oil or grease seals during installation to avoid damage to the seal lips. Before a shaft passes through a seal, apply a little oil, preferably high temperature grease on the lips to reduce rubber to metal friction.

(14) Circlip, Retaining Ring

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

Page 7

GENERAL INFORMATION 1-3

Before Servicing

(15) Cotter Pin

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

(16) Lubrication

Engine wear is generally at its maximum while the engine is warming up and before all the rubbing surfaces have an adequate lubricative ﬁlm. During assembly, oil or grease (whichever is more suitable) should be applied to any rubbing surface which has lost its lubricative ﬁlm. Old grease and dirty oil should be cleaned off. Deteriorated grease has lost its lubricative quality and may contain abrasive foreign particles.

Don’t use just any oil or grease. Some oils and greases in particular should be used only in certain applications and may be harmful if used in an application for which they are not intended. This manual makes reference to molybdenum disulﬁde grease (MoS2) in the assembly of certain engine parts. Always check manufacturer recommendations before using such special lubricants.

(17) Electrical Wires

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

(18) Replacement Parts

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

(19) Inspection

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

Abrasion Crack Hardening Warp Bent Dent Scratch Wear Color change Deterioration Seizure

(20) Speciﬁcations

Speciﬁcation terms are deﬁned as follows:

"Standards" show dimensions or performances which brand-new parts or systems have.

"Service Limits" indicate the usable limits. If the measurement shows excessive wear or deteriorated performance, replace the damaged parts.

Page 8

1-4 GENERAL INFORMATION

Model Identiﬁcation

Electric Starter Model-FH500V

Recoil Starter Model-FH500V

Cylinder Number Designation:

No.1 Cylinder is the left-hand cylinder viewed from the air cleaner. No.2 Cylinder is the right-hand cylinder viewed from the air cleaner.

Page 9

Model Identiﬁcation

Electric Starter Model-FH680V

GENERAL INFORMATION 1-5

Page 10

1-6 GENERAL INFORMATION

General Speciﬁcations

Items

Type of engine Cylinder layout 90 V-Twin Bore x Stroke 68 mm x 68 mm (2.68 in x 2.68 in) 75.2 mm x 76 mm (2.96 in x 2.99 in) Piston displacement 494 mL (30.1 cu. in) 675 mL (41.19 cu.in) Direction of rotation Counterclockwise facing the PTO shaft Compression release Automatic compression release Low idle speed 1550 rpm Fast idle speed 3600 rpm Ignition system Transistorized-ﬂy wheel magneto RFI Per Canada and U.S.A. requirements Starting system Electric starter and/or recoil starter Charging system 12 V - 13 amps with regulator Spark plug CHAMPION RCJ8Y NGK BPR4ES Carburetor Float type, ﬁxed main jet Float type, ﬁxed main jet, two barrel Fuel pump Diaphragm type pulse pump Air cleaner Dual stage element, dry type Governor Flyweight all speed governor Lubrication system Pressure feed by positive displacement pump

Oil ﬁlter Cartridge type full ﬂow ﬁlter Oil pressuer switch ON-OFF switch Oil capacity

(when engine is completely dry)

Cooling system Forced air cooling by fan Dimensions (L x W x H ) 425 mm x 359 mm x 324 mm 458 mm x 430 mm x 381mm

Electric starter model (16.7 in x 14.1 in x 12.8 in) (18.0 in x 16.9 in x 15.0 in)

Recoil starter model (16.7 in x 14.1 in x 14.2 in)

Dry weight

Electric starter model 34 kg (75 lb) 40.5 kg (89.3 lbs) 41.2 kg Recoil starter model 32 kg (71 lb)

FH451V, FH500V, FH531V FH601V, FH641V, FH680V FH721V

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

1.8 L (1.9 US-qt) 1.9 L

425 mm x 359 mm x 361 mm

(2.0 US-qt)

(90.8 lbs)

Speciﬁcations are subject to change without notice.

Page 11

GENERAL INFORMATION 1-7

Periodic Maintenance Chart

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

Some adjustments require the use of special tools or other equipment. An electronic tachometer will facilitate setting idle and running speeds.

FH451V, FH500V, FH531V

OPERATION INTERVAL

Daily First

Check or clean air intake screen Check and add engine oil Check for fuel and oil leakage Check for loose or lost nut and screw Check battery electrolyte level Clean air cleaner foam element (1) Clean air cleaner paper element (1) Clean dust and dirt from cylinder and

cylinder head ﬁns (1) Tighten nut and screws

Change engine oil Clean and re-gap spark plugs Change Oil ﬁlter Change air cleaner paper element (1)

Check and adjust vlave clearance Clean and lap valve seating surface Clean combustion chamber

(1): Service more frequently under dusty conditions.

: These items must be performed with the proper tools. See your authorized Kawasaki Engine Dealer for service,

unless you have the proper equipment and mechanical proﬁciency.

•

8hr.

• •

Every 25 hr.

•

Every 50 hr.

•

Every

100 hr.

•

Every

200 hr.

•

Every

300 hr.

•

Page 12

1-8 GENERAL INFORMATION

Periodic Maintenance Chart

FH601V, FH641V, FH680V, FH721V

OPERATION

Daily First

cylinder head ﬁns (1) Tighten nut and screws

Change engine oil Clean and re-gap spark plugs Check and clean oil cooler ﬁns (FH721V

engines). Change Oil ﬁlter

Change air cleaner paper element (1)

Check and adjust vlave clearance Clean and lap valve seating surface Clean combustion chamber

(1): Service more frequently under dusty conditions.

: These items must be performed with the proper tools. See your authorized Kawasaki Engine Dealer for service,

unless you have the proper equipment and mechanical proﬁciency.

•

8hr.

• •

Every 25 hr.

•

INTERVAL

Every 50 hr.

Every

100 hr.

•

Every

200 hr.

•

Every

300 hr.

•

Page 13

GENERAL INFORMATION 1-9

Torque and Locking Agent

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

locking agent or liquid gasket.

Letters used in the "Remarks" column mean:

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

S:Tighten the fasteners following the speciﬁed sequence.

SS : Apply silicone sealant.

FH451V, FH500V, FH531V

Fastener

Fuel System:

Choke Valve Screw 0.7 0.07 6in1lb

Throttle Valve Screws 1.0 0.10 9in

Pilot Jet 1.7 0.17 15 in

Main Jet 0.7 0.07 6in1lb

Main Air Jet 0.7 0.07 6in

Main Nozzle 2.0 0.20 17 in1lb

Pilot Air Jet 0.7 0.07 6in

Drain Screw (Carburetor) 1.3 0.13 11 in

Earth Lead Screw 3.4 0.35 30 in

(Carburetor Side)

Fuel Shut Off Solenoid Valve 6.9 0.70 61 in

(Carburetor)

Float Chamber Mounting Screw 8.8 0.90 78 in-lb

(Carburetor) Governor Arm Clamp Nut 7.8 0.8 69 in1lb Governor Shaft Plate Screws 2.0 0.20 18 in-lb Holder Plate Nuts (Air Cleaner, 5.9 0.60 52 in

Carburetor Mounting) Intake Manifold Mounting Bolts 5.9 0.6 52 in Cleaner Body Mounting Screws 3.4 0.35 30 in Control Panel Mounting Bolts 5.9 0.6 52 in1lb

Cooling System:

Engine-shoroud Bolt (M8) 15 1.5 11 Engine-shoroud Bolts (M6) 5.9 0.6 52 in1lb Plug Bolt (Engine-shroud) 5.9 0.6 52 in1lb Plug Screw (Engine-shroud) 3.4 0.35 30 in

Engine Top End

Cylinder Head Bolts 25 2.6 19.0 =S Valve Clearance Lock Screws 6.9 0.70 61 in1lb Connecting Rod Big End 5.9 0.60 52 in1lb =O

Cap Bolts Rocker Arm Bolts 28 2.8 20 Rocker Cover Mounting Bolts 5.9 0.6 52 in1lb Exhaust Pipe Flange Nuts 15 1.5 11 Spark Plugs 22 2.2 16

FH451V, FH500V, FH531V

Torque

kg1m ft1lb

Remarks

Page 14

1-10 GENERAL INFORMATION

Torque and Locking Agent

Fastener

Lubrication System:

Engine Drian Plugs (Plastic) Engine Drain Plug (Metal) 20 2.0 14.5 Engine Drain Plug Joint (Plastic) 17 1.7 12.0 Engine Drain Plug Joint (Metal) 39 4.0 29 Oil Pressure Switch Oil Passage Plug 3.9 0.40 35 in1lb Oil Pump Cover Plate Mounting Bolts 5.9 0.6 52 in1lb Oil Filter in the text

Camshaft/Crankshaft:

Crankcase Cover Bolts 25 2.6 19.0 =S Breather Chamber Cover Bolts 5.9 0.6 52 in

Electrical System:

Starter Coil Screws 3.4 0.35 30 in1lb Flywheel Bolt 56 5.7 41 Fan Housing Bolts 5.9 0.6 52 in1lb Screen Bolts 5.9 0.6 52 in1lb Regulator Screws 3.4 0.35 30 in Ignition Coil Bolts (Studs) 7.8 0.8 69 in Ignition Coil Bolts (Bolts) 5.9 0.6 52 in1lb Starter Motor Mounting Bolts 15 1.5 11 Recoil Starter Mounting Nuts 5.9 0.6 52 in1lb Recoil Starter Retainier Screw 7.8 0.8 69 in1lb Spark Plugs 15 1.5 11.0

FH451V, FH500V, FH531V

Torque

N1m kg1m ft1lb

6.9 0.70 61 in1lb

9.8 1.0 87 in

Remarks

=SS

Page 15

Torque and Locking Agent

FH601V, FH641V, FH680V, FH721V

GENERAL INFORMATION 1-11

Fasteners

Fuel System:

Choke Valve Screw 1.0 0.10 8.9 in Throttle Valve Screws Pilot Jet – – – Main Jet – – Plug, Main Jet 19 1.9 14 Main Nozzle – – – Main Air Jet – – – Pilot Air Jet – – – Drain Screw(Carburetor) 2.0 0.2 18 in1lb Earth lead screw – – –

(Carburetor Side) Fuel Shut Off Solenoid Valve (Carburetor) 20 2.0 15

Float Chamber Mounting 3.9 0.4 35 in1lb Screw(Carburetor) Governor Arm Clamp Nut 7.8 0.8 69 in Governor Shaft Plate Screws 2.0 0.2 18 in Intake Pipe Mounting Bolts and Nuts 5.9 0.6 52 in1lb

Intake Manifold Mounting Bolts 5.9 0.6 52 in1lb Cleaner Body Mounting Screws – – – Control Panel Mounting Bolts 5.9 0.6 52 in

Cooling System:

Engine-shroud Bolt (M8) 15 1.5 11 Engine-shroud Bolts (M6) 5.9 0.6 52 in Plug Bolt (Engine-shroud) – – – Plug Screw (Engine-shroud) 3.4 0.35 30 in

Engine Top End:

Cylinder Head Bolts 25 2.6 19 =S Valve Clearance Lock Screws 6.9 0.7 61 in Connecting Rod Big End 21 2.1 15 =O Cap Bolts Rocker Arm Bolts 28 2.8 20 Rocker Cover Mounting Bolts 5.9 0.6 52 in-lb Exhaust Pipe Flange Nuts 15 1.5 11 Spark Plugs 22 2.2 16

FH601V, FH641V, FH680V, FH721V

Torque

1.0 0.10 8.9 in

kg1m ft1lb

Remarks

=L =L

Page 16

1-12 GENERAL INFORMATION

Torque and Locking Agent

Fastener

Lubrication System:

Engine Drian Plugs (Plastic) Engine Drain Plug (Metal) 20 2.0 14.5 Engine Drain Plug Joint (Plastic) 17 1.7 12 Engine Drain Plug Joint (Metal) 39 4.0 29 Oil Pressure Switch Oil Passage Plug 3.9 0.40 35 in1lb Oil Pump Cover Plate Mounting Bolts 5.9 0.6 52 in1lb Oil Filter in the text Oil Cooler Mounting Joint 44 4.5 33

Camshaft/Crankshaft:

Crankcase Cover Bolts Breather Chamber Cover Bolts 5.9 0.6 52 in1lb

Electrical System:

Starter Coil Screws 3.4 0.35 30 in Flywheel Bolt 56 5.7 41 Fan Housing Bolts 5.9 0.6 52 in1lb Screen Bolts 5.9 0.6 52 in Regulator Screws 3.4 0.35 30 in Ignition Coil Bolts (Studs) 7.8 0.8 69 in1lb Ignition Coil Bolts (Bolts) 5.9 0.6 52 in Starter Motor Mounting Bolts 15 1.5 11 Recoil Starter Mounting Nuts – – – Recoil Starter Retainier Screw – – – Spark Plugs 22 2.2 16

FH601V, FH641V, FH680V, FH721V

Torque

N1m kg1m ft1lb

6.9 0.7 61 in1lb

9.8 1.0 87 in

25 2.6 19.0 =S

Remarks

=SS

S:Tighten the fasteners following the speciﬁed sequence.

SS : Apply silicone sealant.

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

Basic Torque for General Fasteners

Threads dia

Torque

(mm) N1m kg1m ft1lb

4 2.0 0.2 17 in1lb 5 3.4 0.35 30 in1lb 6 5.9 0.6 52 in-lb 8 15 1.5 11

Page 17

Special Tools

GENERAL INFORMATION 1-13

Compression Gauge: 57001–221

Piston Ring Pliers: 57001–115

Piston Ring Compression Grip: 57001–1095

Valve Seat Cutter Holder Ø6: 57001–1360

Valve Seat Cutter, 45- Ø35.0: 57001–1116

Valve Seat Cutter, 30- Ø 33.0: 57001–1199

Piston Ring Compression Belt, Ø67 -Ø79: 57001–1097

Valve Seat Cutter Holder Bar: 57001–1128

Compression Gauge Adapter M14 x 1.25: 57001–1159

Valve Seat Cutter, 30- Ø 30.0: 57001–1120

Page 18

1-14 GENERAL INFORMATION

Special Tools

Oil Filter Wrench : 57001–1249

Hand Tester: 57001–1394

Kawasaki Bond (Silicone Sealant) : 56019–120

Page 19

FUEL SYSTEM 2-1

Fuel System

Table of Contents

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

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

Governor Link Mechanism..........................................2-9

Control Panel Assembly Removal........................2-9

Control Panel Assembly Installation.....................2-9

Governor Arm Removal........................................2-9

Governor Arm Installation...................................2-10

Governor Assembly Removal.............................2-10

Governor Assembly Installation..........................2-10

Governor Assembly Inspection...........................2-11

Governor Shaft Removal....................................2-11

Governor Shaft Installation.................................2-11

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

Fuel and Air Flow...............................................2-12

Fuel Shut Off Solenoid Valve (Electric Starter

Model).................................................................2-13

Low Idle Speed Adjustment................................2-13

High Idle Speed Adjustment...............................2-13

High Altitude Operation......................................2-14

Main Jet Replacement........................................2-14

Fuel system Cleanliness Inspection...................2-15

Carburetor Removal............................................2-16

Carburetor Installation........................................2-16

Carburetor Disassembly/Assembly - FH451V, 500V,

531V...................................................................2-17

Carburetor Disassembly/Assembly-FH601V, 641V,

680V, 721V..........................................................2-18

Carburetor Cleaning...........................................2-19

Carburetor Inspection.........................................2-20

Fuel Shut-Off Solenoid Valve Test (ElectricStarter

Model).................................................................2-21

Intake Manifold..........................................................2-22

Intake Manifold Removal....................................2-22

Intake Manifold Installation.................................2-22

Intake Manifold Inspection..................................2-23

Fuel Pump, Fuel Filter...............................................2-24

Fuel Pump Inspection.........................................2-24

Fuel Filter Inspection..........................................2-24

Air Cleaner.................................................................2-25

Element Removal - FH451V, 500V, 531V..........2-25

Element Removal - FH601V, 641V, 680V, 721V 2-25

Element Installation............................................2-25

Element Cleaning and Inspection - FH451V, 500V,

531V...................................................................2-25

Element Cleaning and Inspection - FH601V, 641V,

680V, 721V ........................................................2-26

Cleaner Body Removal - FH451V, 500V, 531V..2-26 Cleaner Body Removal - FH601V, FH641V, FH680V,

FH721V .............................................................2-27

Cleaner Body Installation - FH451V, 500V, 531V2-27 Cleaner Body Installation - FH601V, 641V, 680V,

721V ..................................................................2-27

Housing (Case and Body) Inspection.................2-28

Page 20

2-2 FUEL SYSTEM

Exploded View

[FH451V, FH500V, FH531V]

Page 21

Exploded View

[FH451V, FH500V, FH531V]

1. Pilot Screw

2. Pilot Air Jet

3. Main Air Jet

4. Main Jet

5. Pilot Jet

6. Solenoid Valve

FUEL SYSTEM 2-3

T1: 0.7 N T2: 1.0 N T3: 1.3 N T4: 1.7 N T5: 2.0 N T6: 3.4 N T7: 3.9 N T8: 6.9 N T9: 7.8 N

T10: 8.8 N

m (0.07 kg

m (0.10 kg

m (0.13 kg

m (0.17 kg

m (0.20 kg

m (0.35 kg

m (0.40 kg

m (0.70 kg

m (0.80 kg

m (0.90 kg

m, 6 in

m, 9 in

m, 11 in

m, 15 in

m, 17 in

m, 30 in

m, 35 in

m, 61 in

m, 69 in

m, 78 in

lb)

Page 22

2-4 FUEL SYSTEM

Exploded View

[FH601V, FH641V, FH680V, FH721V]

Page 23

Exploded View

[FH601V, FH641V, FH680V, FH721V]

1. Pilot Screw

2. Pilot Air Jet

3. Main Air Jet

4. Main Jet

5. Pilot Jet

6. Solenoid Valve

FUEL SYSTEM 2-5

T1: 1.0 N T2: 3.9 N T3: 2.0 N T4: 19 N T5: 20 N T6: 6.9 N

m (0.10 kg

m (0.40 kg

m (0.20 kg

m (1.9 kg

m (2.0 kg

m (0.70 kg

m, 9 in

m, 35 in

m, 18 in

m, 14 ft

m, 15 ft

m, 61 in

lb)

Page 24

2-6 FUEL SYSTEM

Exploded View

Page 25

Exploded View

[FH451V, FH500V, FH531V]

T5: 2.0 N T8: 5.9 N T9: 7.8 N

[FH601V, FH641V, FH680V, FH721V]

T5: 2.0 N T8: 5.9 N T9: 7.8 N

O: Apply engine oil.

m (0.20 kg

m (0.60 kg1m , 52 in

m (0.80 kg1m , 69 in

m (0.20 kg

m (0.60 kg

m (0.80 kg1m , 69 in

m , 17 in

m , 52 in

lb)

FUEL SYSTEM 2-7

Page 26

2-8 FUEL SYSTEM

Speciﬁcations

Standard

Item

Caburetors Speciﬁcations:

Make/ type MIKUNI B24T1 Throttle bore diameter 24 mm (0.94 in.) Venturi diameter 16 mm (0.63 in.) 18 mm (0.71 in.) 21 mm (0.83 in.) Main Jet (MJ) #125 #116.3 L: #136, R: #140 Pilot jet (PJ) #48.8 #43.8 L: #46, R: #44 Main air jet (MAJ) ø1.7 ø1.4 Pilot air jet (PAJ) ø1.2 ø0.8

Pilot air screw turns out (PS) 2 1/4 1 3/8 L: 2 1/4, R: 1 1/4

(Idle mixture screw turns out)

Float level Float parallel to carburetor body

Idle Speed: (1)

Low idle speed 1550 r/min (rpm) High idle speed 3600 r/min (rpm)

Air Cleaner:

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

Fuel:

Fuel requirement Unleaded regular grade gasoline

Fuel Pump:

Type Pulse-diaphragm pump

Governor:

Type Flyweight all speed governor

FH451V, FH500V,

FH531V

FH601V, FH641V, FH680V,

Nikki 621266 26 mm (1.02 in.)



1.7



1.1

FH721V

(1) Idle speeds may vary depending on each equipment. Refer to the equipment speciﬁcation.

Page 27

Governor Link Mechanism

Control Panel Assembly Removal

Remove:

•

Air Cleaner (see Cleaner Body Removal) Air Cleaner Mount Bracket Bolts [A] Air Cleaner Mount Bracket [B] Earth Lead (Starter Model) Control Panel Mounting Bolts [C]

Remove the control panel assembly [A] while unhooking the governor

•

spring [B] end loop at the panel bracket. Clear the choke link rod lower end [C] from the choke lever.

•

FUEL SYSTEM 2-9

Control Panel Assembly Installation

Before installing the control panel assembly, check to see that the

•

choke lever [A] and engine speed control lever [B] move smoothly in all directions. If any part is worn or damaged, replace the control panel assembly. After installation, adjust the low idle speeds and high idle speeds

•

to the speciﬁcations (see Low Idle Speed and High Idle Speed adjustment).

Governor Arm Removal

Remove:

•

Control Panel Assembly Loosen the clamp nut [A] and take off the governor arm [B].

•

Unhooking the throttle link rod spring [C] end loop and clear the

•

throttle link rod lower end [D].

Page 28

2-10 FUEL SYSTEM

Governor Link Mechanism

Governor Arm Installation

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

•

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

•

and that it pulls the governor arm and throttle lever [E] each other.

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

•

governor shaft.

Turn the top end of the governor arm counterclockwise to fully open

•

the carburetor [G] throttle valve and hold it there.

Turn the governor shaft counterclockwise, fully turn the shaft to end

•

of its travel.

Tighten the clamp nut.

•

Torque - Governor Arm Clamp Nut: 7.8 N1m (0.80 kg

Be sure the governor shaft extend from the governor arm is approxi-

•

mately 7 mm (0.3 in) [H] as shown.

Install the control panel assembly, and connect the governor arm with

•

the governor spring.

m, 69 in1lb)

Governor Assembly Removal

Remove the crankcase cover (see Camshaft/Crankshaft chapter).

•

Remove the push rod. (see Engine Top End chapter)

•

Upside down the engine.

•

Remove the camshaft [A].

•

Remove:

•

Washer [A]

Snap Ring [B]

Sleeve [C]

Governor Plate [D]

Snap Ring [B]

Steel balls [E]

Ball Guide [F]

Ball Plate [G]

Governor Assembly Installation

Fit the snap rings [A] into the grooves securely.

•

Spin the governor plate by hand and check that the steel balls and

•

governor plate operate freely.

Page 29

Governor Link Mechanism

Governor Assembly Inspection



Visually check all governor parts for wear and damage. If any parts are worm or damaged, replace them.

Governor Shaft Removal

Split the crankcase (see Camshaft/Crankcase chapter).

•

Unscrewthe governor shaft plate screws [A], and pull out the governor

•

shaft [B] outside.

NOTE



It is not necessary to remove the governor shaft unless it is being replaced.

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

•

been damaged.

The oil seal [A] must be assembled with seal lip towards inside of the

•

engine. Press in the oil seal 0

•

crankcase surface [C].

1.0 mm (0.04 in.) [B] ﬂush or below the

FUEL SYSTEM 2-11

Governor Shaft Installation

Apply engine oil to the governor shaft.

•

Insert the governor shaft into the crankcase.

•

Install the governor shaft plate [A] to the shaft [B] as shown.

•

Torque - Governor Shaft Plate Screws: 2.0 N1m (0.20 kg1m, 17 in1lb)

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

•

NOTE



If the oil seal is removed, oil seal is put on after shaft is installed.

Page 30

2-12 FUEL SYSTEM

Carburetor

Fuel and Air Flow

The main system of the carburetor consists of the main jet [A], Valve seat [B] main nozzle [C], and the main air passage [D] (main air jet [E]). The main system meters fuel to the engine during moderate to heavy load conditions. Fuel ﬂows through the main jet and into the main nozzle, where it is joined by air from the main air passage (main air jet). The resulting mixture ﬂows out the end of the main nozzle into the carburetor bore, where it is atomized by the high speed air ﬂow, and carried into the engine.

The pilot system includes the pilot jet [F], pilot screw [G] (Idle mixture screw), pilot air jet [H], pilot outlet [I], and the bypass holes [J]. The pilot system meters the fuel/air mixture while the engine is idling and running under a light load. Under these conditions there is very little air ﬂow through the carburetor bore; so little that it is not enough to draw fuel through the main system of the carburetor and atomize it. Instead, the fuel is drawn through the pilot system, since the nearly closed throttle valve [K] causes high speed air ﬂow past the pilot outlet and bypass holes (even at low engine speed).

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

Main Fuel Flow Pilot Fuel Flow ⇒

Page 31

Carburetor

Fuel Shut Off Solenoid Valve (Electric Starter Model)

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

The valve opens automatically when the switch key is turned to the “Run” position.

Low Idle Speed Adjustment

Disconnect all possible external loads from the engine.

•

Start the engine and warm it up thoroughly.

•

Always keep your hands clear of the moving parts.

Move the throttle lever on dash to the idle position, and hold the

•

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

arm clockwise all the way) and adjust the low idle speed screw [A]

until the engine idles at speciﬁed speed. - F

H451V,500V,531V

FUEL SYSTEM 2-13

Adjust the low idle speed screw [C] with Phillips Screwedriver [D] until

•

the engine idles at speciﬁed speed.– F

Idle Speed (Carburetor idle rpm)

1450 rpm

Release the throttle lever and adjust the low idle speed set screw [B]

•

on the control plate to obtain the speciﬁed governed low idle speed.

Low Idle Speed (Governed idle rpm)

1550 rpm

High Idle Speed Adjustment

NOTE



High idle speed adjustment should be made after the idle speed adjustment is performed.

H601V,641V,680V,721V

CAUTION

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

Start and warm up the engine thoroughly.

•

Page 32

2-14 FUEL SYSTEM

Carburetor

Always keep your hands clear of the moving parts.

Move the throttle lever at a dash to the high idle position and match

•

the lever hole position with the panel hole by inserting 6 mm dia., pin or bolt [A]. Loosen two M6 control panel mounting bolts [B] enough to move the

•

control panel assembly. Carefully move the control panel assembly right side [C] up or down

•

to obtain the speciﬁed high idle speed.

High Idle Speed

3600 rpm

Tighten the M6 Mounting bolts.

•

Torque - Control Panel Mounting Bolts: 5.9 N

Remove the 6 mm dia., pin or bolt.

•

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

•

CAUTION

Be sure to make the idle and high idle speeds respectively correspond to those of the equipment.

m (0.60 kg

m, 52 in1lb)

High Altitude Operation

At high altitude, the standard carburetor air-fuel mixture will be excessively rich. Performance will decrease, and fuel consumption will increase. High altitude performance can be improved by installing a smaller diameter main-jet in the carburetor and correct idle speed.

NOTE



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

High Altitude Main Jet

Main Jet No

Altitude FH451V, FH531V FH601V,

FH500V FH641V,

FH680V,

FH721V 0 1 000 m (0 3 000 ft) #125 #116.3 L: #136 R: #140 1 000 2 000 m #122.5 #113.8 L: #133 R: #139

(3 000 6 000 ft)

2 000 m (6 000 ft) #120 #111.3 L: #130 R: #134

and higher

Main Jet Replacement

Place the engine (equipment) on a level surface.

•

Close the fuel shut off valve in the equipment.

•

Drain the fuel in the carburetor completely by unscrewing the drain

•

screw at the bottom of the ﬂoat chamber. Remove the carburetor (see Carburetor Removal).

•

Unscrew the ﬂoat chamber bolt [A] and take off the ﬂoat chamber [B].

•

Unscrew the solenoid valve, and take off the valve and gasket.

•

(Electric Starter Model)

Page 33

Carburetor

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

•

with a new one for altitude expected. Tighten the main jet to the speciﬁcation (see Carburetor Disassembly

•

Assembly Notes). Install the ﬂoat chamber, gasket and solenoid valve.– F

•

531V

Remove the carburetor (see Carburetor Removal).

•

Unscrew the main jet plugs [C] and take off the main jet plugs and

•

gaskets. Make sure that “L”[L] or “R”[R] mark on the ﬂoat chamber is shown

•

the main jet position. Using a proper blade screw driver, carefully replace the main jet [D]

•

with a new one for altitude expected. Tighten the main jet to the speciﬁcation (see Carburetor Disassembly/

•

Assembly). Install the gasket and the main jet plug-F

•

Torque - Main Jet Plug: 19 N1m (1.9 kg1m, 14 ft

H601V, 641V, 680V, 721V.

lb)

H451V,500V

FUEL SYSTEM 2-15

Fuel system Cleanliness Inspection

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

Remove the air cleaner. (see Cleaner Body Removal)

•

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

•

carburetor. Turn out the drain screw a few turns to drain the carburetor and check

•

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

•

Torque - [FH451V, 500V, 531V]

Drain Screw: 1.3 N [FH601V, 641V, 680V, 721V] Drain Screw: 2.0 N

If any water or dirt is found, clean the carburetor (see Carburetor

•

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

m (0.13 kg1m, 11 in1lb)

m (0.2 kg

m, 18 in1lb)

Page 34

2-16 FUEL SYSTEM

Carburetor

Carburetor Removal

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

Remove:

•

Air Cleaner and Related Parts (see Cleaner Body).

Turn the fuel shut off valve to the OFF position.

•

Drain the carburetor.

•

Disconnect the fuel tube at the fuel inlet joint [A] of the carburetor.

•

Disconnect the solenoid valve lead terminal and remove the earth

•

terminal (Electric Starter Model). Unhook the throttle link spring [B] at the throttle shaft lever [C] top

•

end with a long nose plier. Unhook the throttle [D] and choke link rods [E] at the top ends of their

•

arms while pull off the carburetor - F Unhook the throttle link spring [B] at the link clip [F] with a long nose

•

plier. Unhook the link clip [F] and remove the throttle [D] and choke link rods

•

[E] at the ends of their arms while pull off the carburetor - F 641V, 680V, 721V.

H451V,500V,531V

H601V,

Carburetor Installation

Clean the mating surfaces of the carburetor and intake manifold, and

•

ﬁt the new gaskets. Take care not to bend the throttle and choke link rods during

•

installation. Make sure the link spring around the throttle link rod is inplace and that it pulls the governor arm and carburetor throttle shaft lever toward each other. Be sure the fuel tube clip ends [A] face horizontal direction.

•

Improper installation of the fuel intake hose clamp can result in gasoline leakage and potential ﬁre hazard.

Be sure the clip ends of the hose clamp face in a horizontal direction. In a vertical position (see illustration), the clip ends [A] can come into contact with the intake pipe and become loose.

Adjust:

•

Carburetor Pilot Screw Idle Speed

Page 35

Carburetor

Carburetor Disassembly/Assembly

- FH451V, 500V, 531V

Refer to the illustration shown for disassembly and assembly.

•

There are several passage plugs (Ball plugs) in the carburetor body.

•

Do not remove. Before disassembly, mark the out side of choke valve and throttle

•

valves for assembling them. Replace the pilot screw in accordance with the following procedure if

•

necessary.



Carefully mark the position of the pilot screw limiter on the carburetor body so that it can be installed and set to its original position later.



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



Turn the pilot screw clockwise and count the number of turns until screw is gently seated in the pilot passage. Record the number of turns needed to closed the screw.



Turn out the pilot screw to replace it with anew one.



Install the new pilot screw until the screw is gently seated. Then open the screw the same number of turns as recorded prior to removal.



Align the limiter with the mark on the carburetor body to install, taking care not to turn the pilot screw. Install the choke valve and throttle valve on the shaft as the out side

•

mark of them facing out side. Drive the ﬂoat pin so that it’s big diameter side faces the engine ﬂange

•

side. The fuel inlet valve seat is pressed into the carburetor body and is

•

not replaceable. Assemble carburetor parts which recommended tightening torque.

•

(see Exploded View)

1. Limiter 19. Main Nozzle

2. Pilot Screw 20. Valve Seat

3. Spring 21. Float Chamber

4. Low Idle Speed Screw 22. Gasket

5. Spring 23. Bolt

6. Seal 24. Gasket

7. Ring 25. Solenoid Valve

8. Throttle Shaft (Electric Starter Model)

9. Throttle Valve 26. Drain Screw

10. Screws 27. Gasket

11. Pilot Jet 28. Pin

12. Screw 29. Snap Ring

13. Choke Valve 30. Float Valve

14. Choke Shaft 31. Main Air Jet

15. Spring 32. Air Jet

16. Coller 33. Washer

17. Main jet 34. E Type Circlip

18. Float 35. Cap

36. Earth Lead (Electric Starter Model)

FUEL SYSTEM 2-17

Page 36

2-18 FUEL SYSTEM

Carburetor

Carburetor Disassembly/AssemblyFH601V, 641V, 680V, 721V.

Refer to the illustration shown for disassembly and assembly.

•

There are several passage plugs (Ball plugs) in the carburetor body.

•

Do not remove. Before disassembly, mark the out side of choke valve and throttle

•

valves for assembling them.

1. Plug Pilot Screw 15. Float

2. Pilot Screw 16. Gasket

3. Low Idle Speed Screw 17. Float Chamber

4. Spring 18. Screw

5. Seal 19. Clamp

6. Collar 20. Plug Main Jet

7. Throttle Valve 21. Gasket

8. Screws 22. Main Jet: L

9. Throttle Shaft 23. Main Jet: R

10. Choke Valve 24. Slow Jet

11. Choke Shaft 25. Drain Screw

12. Seal 26. Spring

13. Float Valve 27. Gasket

14. Pin 28. Solenoid Valve

Replace the pilot screw [A] in accordance with the following procedure

•

if necessary.



Remove the pilot screw plug [B](material: Stainless steel) as follows: Punch a hole in the plug and pry it out with an awl or other suitable tool.



Turn in the pilot screw and count the number of turns until it seats fully but not tightly, and then remove the screw. This is to set the screw to its original position when assembling.



Turn in the new pilot screw[A] fully but not tightly, and then back it out the same number of turns counted during disassembly.



Install a new pilot screw plug [B] in the pilot screw hole by pressing with the rod[C], and apply a small amount of a bonding agent [D] to the circumference of the plug to ﬁx the plug. Install the choke valve and throttle valve on the shaft as the out side

•

mark of them facing out side, and apply a small amount of a bonding agent to the valve screw threads.

CAUTION

Do not apply too much bonding agent to the valve screws itself may be ﬁxed.

Page 37

Carburetor

Drive the ﬂoat pin so that it’s big diameter side faces the throttle shaft

•

lever side. The fuel inlet valve seat is pressed into the carburetor body and is

•

not replacable. Assemble carburetor parts which recommended tightening torque.

•

(see Exploded View)

FUEL SYSTEM 2-19

Carburetor Cleaning

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

CAUTION

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

Disassemble the carburetor.

•

Immerse all the carburetor metal parts in a carburetor cleaning

•

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

•

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

•

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

•

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

•

Page 38

2-20 FUEL SYSTEM

Carburetor

Carburetor Inspection

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

Inspect the carburetor body for damage. Flange sealing surfaces

•

should be smooth and free of burns and nicks. Replace the gasket if necessary. Turn the throttle and choke shafts to check that the throttle and choke

•

butterﬂy valves move smoothly. If the valves do not move smoothly, replace the carburetor body and/ or throttle shaft and choke shaft assembly. 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 damage. Replace

•

the part if necessary. Clean and check the ﬂoat level as follows.

•

CAUTION

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

With the ﬂoat [A] assembly installed onto the carburetor body [B],

•

hold the carburetor upside down at eye level. Gently support the ﬂoat with a ﬁnger and bring it down slowly so that the ﬂoat arm tab [C] just touches the ﬂoat valve [D]. The ﬂoat lower surface [E] should be parallel with the carburetor body mating surfaces [F]. If the ﬂoat position is not correct, replace the ﬂoat with a new one.

Inspect the ﬂoat valve for excessive wear or damage. The tip should

•

be smooth, without any grooves, scratches, or tears. The rod at the other end of the needle should move smoothly when push in and released. If either the needle or the seat is worn or damaged, replace the ﬂoat assembly and carburetor body as a set.

Inspect the tapered portion [A] of the pilot screw [B] for wear or

•

damage. If the pilot screw is worn or damaged on the taper portion, replace it. Check the spring for weakened condition, replace it, if necessary.

•

Page 39

Carburetor

Fuel Shut-Off Solenoid Valve Test (Electric Starter Model)

Unscrew the fuel shut off valve and remove the valve.

•

Connect a 12 VDC source to the solenoid as shown.

•

If the actuate solenoid plunger (Needle Valve) does not pop in when the Test Voltage is applied, replace it.

NOTE



If may be necessary to push the plunger slightly for the plunger to withdraw.

FUEL SYSTEM 2-21

Page 40

2-22 FUEL SYSTEM

Intake Manifold

Intake Manifold Removal

Remove:

•

Air Cleaner (see Cleaner Body Removal) Engine Upper Cover

Cut off the band [A] and harness and/or wire lead are released from

•

intake manifold. Unscrew the manifold mounting bolts [B].

•

Then lifting up the intake manifold middle [A] pull out the intake

•

manifold from the carburetor [B] as shown.

Intake Manifold Installation

Replace the intake manifold gasket with new ones.

•

Clean the mating surfaces of the cylinders and intake manifolds and

•

ﬁt a new gaskets [A] direction as shown.

[B] Distance (FH451V, 500V, 531V): 6 mm [B] Distance (FH601V, 641V, 680V, 721V): 12 mm

Clean the mating surfaces of the carburetor and intake manifold and

•

install the new gaskets [A] and insulator [B] sequence as shown. Install the intake manifold.

•

Tighten the mounting bolts.

•

Torque - Intake Manifold Mounting Bolts: 5.9 N1m (0.6 kg1m, 52 in1lb)

Install and tighten the band [A] around the manifold [B] and wirelead

•

[C] and/or harness [D].



Position the wire and/or harness on top of the manifold as shown. Cut excess the band off.

•

Install the other removed parts.

•

Page 41

Intake Manifold

Intake Manifold Inspection

Inspect the intake manifold for cracks or porous casting.

•

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

•

suspected area with mixture of 25% kerosene and 75% light engine oil. Wipe the area dry and immediately apply a coating of zinc oxide

•

dissolved in wood alcohol. If a cracks is present, the coating will become discolored at the defective area. If a crack is present in the intake manifold, replace it. Inspect the gasket surfaces for burns and nicks.

•

FUEL SYSTEM 2-23

Page 42

2-24 FUEL SYSTEM

Fuel Pump, Fuel Filter

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

is noticed replace it with a new one.

Fuel Pump Inspection

Check the vent hole [A] and ﬁlter [B] for plugging or clogging.

•

If vent hole and ﬁlter are plugged or clogged, remove the foreign matter from them.

Fuel Flow Test:

Disconnect the fuel pump outlet nozzle from the tube.

•

Connect a suitable hose [A] to the outlet nozzle.

•

Run the lower end of the hose into a container.

•

Start the engine, Check the fuel ﬂow.

•

If fuel ﬂow is none or little, replace the fuel pump. Check for clogged or damaged tubes and fuel ﬁlter. Replace the faulty parts.

Fuel Filter Inspection

Visually inspect the fuel ﬁlter [A].

•

If the ﬁlter is clear with no signs of dirt or other contamination, 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.

Page 43

Air Cleaner

Element Removal - FH451V, 500V, 531V

Pull the hooks [A] to outside and remove the air cleaner cover [B].

•

Remove:

•

Wing Bolt [A] Foam Element [B] Paper Element [C]

FUEL SYSTEM 2-25

Element Removal - FH601V, 641V, 680V, 721V

Remove

•

Air Cleaner Case Nut Air Cleaner Case Wing Nut [A] Foam Element [B] Paper Element [C]

Element Installation

Install the element correctly on the air cleaner body.

•

Be sure the paper element is in-place in the air cleaner body.

•

Be sure the foam element is in-place on the paper element body.

•

Element Cleaning and Inspection - FH451V, 500V, 531V

NOTE



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

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

Remove the foam element and the paper element.

•

Clean the foam element [A] in a bath of detergent and water, and let

•

the element air-dry throughly before install it.

Page 44

2-26 FUEL SYSTEM

Air Cleaner

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

•

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

CAUTION

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

Element Cleaning and Inspection - FH601V, 641V, 680V, 721V

See Element Cleaning and Inspection - FH451V, 500V, 531V

•

Foam Element [A] Paper Element [B]

Cleaner Body Removal - FH451V, 500V, 531V

Remove the elements. (see Element Removal)

•

Remove the cleaner body mounting screws [A], holder plate nuts [B]

•

and holder plate [C].

Pull the breather tube [A] off the pipe at the back of the body, and

•

remove the cleaner body [B].

Page 45

Air Cleaner

Cleaner Body Removal - FH601V, FH641V, FH680V, FH721V

Remove the element. (see Element Removal).

•

Remove the clamp [A], and take off the breather tube [B].

•

Loosen nuts [C] and remove the solenoid valve wire [D].

•

Unscrew the bolts [E] and remove the intake pipe [F].

•

Cleaner Body Installation - FH451V, 500V, 531V

Connect the breather tube from the crankcase to the pipe at the back

•

of the cleaner body. Tighten the holder plate nuts and cleaner body mounting screws.

•

Torque - Holder Plate Nuts: 5.9 N1m (0.6 kg

Cleaner Body Mounting Screws 3.4 N

Cleaner Body Installation - FH601V, 641V, 680V, 721V

Replace the intake pipe gasket with new ones.

•

Clean the mating surfaces of the carburetor and intake pipe.

•

Install the intake pipe and solenoid valve wire.

•

Tighten the mounting bolts and nuts.

•

Torque - Intake Pipe Mounting Bolts and Nuts: 5.9 N

lb)

Install the sleeve on the intake pipe.

•

Press-in the sleeve [A] to the intake pipe [B] ﬁxing the groove [C] to

•

the projection [D] as following. Connect the breather tube to the pipe at the intake pipe and clip it

•

with a clamp.

m, 52 in

lb)

m (0.35 kg1m, 30 in

m (0.6 kg1m, 52

FUEL SYSTEM 2-27

lb)

Page 46

2-28 FUEL SYSTEM

Air Cleaner

Housing (Case and Body) Inspection

Clean the housing with detergent and water and dry thoroughly.

•

Check the housing for deformation or other damage. The housing

•

must seal well and permit only ﬁltered air to reach the carburetor. If the housing is damaged, it must be replaced. Check that no foreign material is obstructing the air passage.

•

Page 47

COOLING SYSTEM 3-1

Cooling System

Table of Contents

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

Cooling Fan........................................................................................................................................................................3-4

Cooling Fan Removal..................................................................................................................................................3-4

Cooling Fan Installation...............................................................................................................................................3-4

Cooling Fan Inspection................................................................................................................................................3-4

Screen Clearance Adjustment.....................................................................................................................................3-5

Page 48

3-2 COOLING SYSTEM

Exploded View

Page 49

Exploded View

[FH451V, FH500V, FH531V]

T1: 3.9 N T2: 5.9 N T3: 17 N T4: 56 N T5: 7.8 N

[FH601V, FH641V, FH680V, FH721V]

T1: 3.9 N T2: 5.9 N T3: 17 N T4: 56 N T5: 7.8 N

m (0.40 kg

m (0.60 kg

m (1.7 kg

m (5.7 kg

m (0.8 kg

m (0.40 kg

m (0.60 kg

m (1.7 kg

m (5.7 kg1m, 41 ft

m (0.8 kg

m, 35 in

m, 52 in1lb)

m, 12.0 ft1lb)

m, 41 ft

m, 69 in

m, 35 in

m, 52 in1lb)

m, 12.0 ft

m, 69 in1lb)

lb)

COOLING SYSTEM 3-3

Page 50

3-4 COOLING SYSTEM

Cooling Fan

Cooling Fan Removal

Refer to Flywheel Removal in Electrical System chapter.

•

Cooling Fan Installation

Refer to Flywheel Installation in Electrical System chapter.

•

Cooling Fan Inspection

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

•

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

•

CAUTION

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

Page 51

Cooling Fan

Screen Clearance Adjustment

Check clearance between screen [A] and fan housing [B]. If clearance

•

is less than 1 mm, add proper number of spacer [C] between screen and bracket comp [D] to adjust clearance [G] 1

F: Screws G: Clearance 1

3mm

3 mm.

COOLING SYSTEM 3-5

Page 52

Page 53

ENGINE TOP END 4-1

Engine Top End

Table of Contents

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

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

Cylinder Head.....................................................................................................................................................................4-9

Compression Measurement........................................................................................................................................4-9

Cylinder Head Assembly Removal............................................................................................................................4-10

Cylinder Head Assembly Installation.........................................................................................................................4-10

Push Rod Removal....................................................................................................................................................4-11

Push Rod Installation................................................................................................................................................4-11

Push Rod Inspection.................................................................................................................................................4-12

Valve Mechanism Removal/Installation.....................................................................................................................4-12

Cleaning and Inspection............................................................................................................................................4-13

Valves...............................................................................................................................................................................4-14

Valve Clearance Inspection.......................................................................................................................................4-14

Valve Clearance Adjustment.....................................................................................................................................4-14

Valve Seat Inspection................................................................................................................................................4-15

Valve Seat Repair......................................................................................................................................................4-15

Valve Head Thickness...............................................................................................................................................4-17

Valve Stem Runout....................................................................................................................................................4-18

Valve Stem Diameter.................................................................................................................................................4-18

Valve Guide Inside Diameter.....................................................................................................................................4-18

Valve Spring Inspection.............................................................................................................................................4-18

Cylinder, Piston................................................................................................................................................................4-19

Piston Removal..........................................................................................................................................................4-19

Piston Installation......................................................................................................................................................4-20

Piston/Cylinder Seizure.............................................................................................................................................4-21

Piston Cleaning.........................................................................................................................................................4-22

Piston Ring and Ring Groove Wear..........................................................................................................................4-22

Piston Ring End Gap.................................................................................................................................................4-23

Piston Pin, Piston Pin Hole, and Connecting Rod Wear..........................................................................................4-23

Piston Diameter.........................................................................................................................................................4-24

Cylinder Inside Diameter...........................................................................................................................................4-24

Cylinder Boring and Honing......................................................................................................................................4-25

Mufﬂer/Exhaust Pipe Installation......................................................................................................................................4-27

Mufﬂer/Exhaust Pipe Removal..................................................................................................................................4-27

Mufﬂer/Exhaust Pipe Installation...............................................................................................................................4-27

Inspection..................................................................................................................................................................4-27

Page 54

4-2 ENGINE TOP END

Exploded View

Page 55

Exploded View

[FH451V, FH500V, FH531V]

T1: 5.9 N T2: 5.9 N T3: 25 N T4: 28 N T5: 22 N

[FH601V, FH641V, FH680V, FH721V]

T1: 21 N T2: 5.9 N T3: 25 N T4: 28 N T5: 22 N

O: Apply engine oil. G: Apply grease.

S: Follow the speciﬁc tightening sequence.

m (0.60 kg

m (2.6 kg

m (2.8 kg

m (2.2 kg

m (2.1 kg

m (0.60 kg

m (2.6 kg

m (2.8 kg1m, 20 ft

m (2.25 kg

m, 52 in

m, 52 in1lb)

m, 19.5 ft1lb)

m, 20 ft

m, 16 ft

m, 15 ft

m, 52 in1lb)

m, 19.5 ft

m, 16 ft1lb)

lb)

ENGINE TOP END 4-3

Page 56

4-4 ENGINE TOP END

Exploded View

Page 57

Exploded View

[FH451V, FH500V, FH531V]

T2: 15 N

[FH601V, FH641V, FH680V, FH721V]

T2: 15 N

m (1.5 kg

m, 11.0 ft

m, 11.0 ft1lb)

lb)

ENGINE TOP END 4-5

Page 58

4-6 ENGINE TOP END

Speciﬁcations

Item

Cylinder Head:

Cylinder compression (MIN) [390 kPa (57 psi)] (MIN) Cylinder head warp 0.05 mm (0.002 in.)

Valves:

Valve head thickness Intake, Exhaust 0.35 mm (0.014 in.) Valve stem runout Intake, Exhaust 0.05 mm (0.002 in.) Valve stem diameter Intake 5.95 mm (0.0234 in.)

Exhaust 5.93 mm (0.0233 in.) Valve guide inside diameter Intake, Exhaust 6.08 mm (0.239 in.) Valve spring free length Intake, Exhaust 31.0 mm (1.22 in.) Rocker arm push rod rounout Intake, Exhaust 0.5 mm (0.02 in.)

Cylinder, Piston

Piston diameter 67.79 mm (2.669 in.) Piston ring/groove clearance Top 0.15 mm (0.006 in.)

Second 0.12 mm (0.005 in.) Piston ring thickness Top, Second 1.40 mm (0.055 in.) Piston ring end gap Top 0.70 mm (0.028 in.)

Second 0.78 mm (0.031 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 16.05 mm (0.632 in.) Cylinder inside diameter: Standard Cylinder 68.10 mm (2.681 in.)

0.50 mm Oversize 68.60 mm (2.701 in.)

Cylinder bore out round 0.056 mm (0.0022 in.)

Service Limit

FH451V, FH500V, FH531V

Item Standard

FH451V, FH500V, FH531V

Valve clearance Intake, Exhaust 0.075 0.125 mm (0.003 0.005 in.) Valve seating surface angle Intake, Exhaust 45 Valve seating surface width Intake, Exhaust 0.6 0.9 mm (0.024 0.035 in.) Valves guide inside diameter Intake, Exhaust 6.00 6.012 mm

Cylinder bore diamter standard cylinder

Standard cylinder 68.00 67.98 mm

0.50 mm Over size 68.50 68.48 mm



(0.2362 0.2367 in.)

(2.677 2.676 in.)

(2.697 2.696 in.)

Page 59

Speciﬁcations

ENGINE TOP END 4-7

Item

FH601V, FH641V, FH680V, FH721V

Cylinder Head:

Cylinder compression (MIN) [390 kPa (57 psi)] (MIN) Cylinder head warp 0.05 mm (0.002 in.)

Valves:

Valve head thickness Intake, Exhaust 0.35 mm (0.014 in.) Valve stem runout Intake, Exhaust 0.05 mm (0.002 in.) Valve stem diameter Intake 5.95 mm (0.0234 in.)

Cylinder, Piston

Piston diameter 74.99 mm (2.952 in.) Piston ring/groove clearance Top 0.18 mm (0.007 in.)

Second 0.16 mm (0.006 in.) Piston ring thickness Top, Second 1.40 mm (0.055 in.) Piston ring end gap Top 0.65 mm (0.026 in.)

Second 0.78 mm (0.031 in.)

0.50 mm Oversize 75.78 mm (2.983 in.)

Cylinder bore out round 0.056 mm (0.0022 in.)

Service Limit

Item Standard

FH601V, FH641V, FH680V, FH721V

Valve clearance Intake, Exhaust 0.075 0.125 mm (0.003 0.005 in.) Valve seating surface angle Intake, Exhaust 45 Valve seating surface width Intake 0.8 1.4 mm (0.03 0.06 in.)

Exaust 1.1 1.6 mm (0.04 0.06 in.)

Valves guide inside diameter Intake, Exhaust 6.00 6.012 mm

Cylinder bore diamter standard cylinder

Standard cylinder 75.18 75.20 mm

0.50 mm Over size 75.68 75.70 mm



(0.2362 0.2367 in.)

(2.960 2.961 in.)

(2.979 2.980 in.)

Page 60

4-8 ENGINE TOP END

Speciﬁcations

Special Tools - Compression Gauge : 57001 - 221

Compression Gauge Adapter M14 x 1.25: 57001–1159 Piston Ring Pliers: 57001 - 115 Piston Ring Compression Grip: 57001 - 1095 Piston Ring Compression Belt, Valve Seat Cutter Holder Bar: 57001–1128 Valve Seat Cutter Holder, Valve Seat Cutter, 45 Valve Seat Cutter, 30 Valve Seat Cutter, 45 Valve Seat Cutter, 30

6: 57001–1360



35.0 : 57001-1116



33.0 : 57001-1199



30.0 : 57001-1187



30.0 : 57001-1120

67 - 79: 57001–1097

Page 61

Cylinder Head

Compression Measurement

Before measuring compression, do the following.

•



Be sure the battery is fully charged.



Thoroughly warm up the engine so that engine oil between the piston and cylinder wall will help seal compression as it does during normal running.



Stop the engine. Disconnect the spark plug caps of each cylinder and remove the spark

•

plugs. Attach the compression gauge assembly ﬁrmly into one plug hole.

•

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

Compression Gauge Adapter: 57001–1159 [B]

Ground the spark plugs to the engine.

•

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

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

•

starter several times until the compression gauge stops rising; the compression is the highest reading obtainable. (Recoil Model)

Cylinder Compression (MIN) 390 kPa (57 psi)

ENGINE TOP END 4-9

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

•

until the compression gauge stops rising; (Electric Starter Model).

Cylinder Compression (MIN) 390 kPa (57 psi)

Repeat the measurement to the other cylinder.

•

If the compression is higher than the speciﬁed value, the piston rings, cylinder and valves are probably in good condition. If the compression is too high, check the following.

1. Carbon build-up on the piston crown and cylinder head - clean off any carbon on the piston crown and cylinder head.

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

3. Valve guides and piston rings - rapid carbon accumulation in the combustion chamber may be caused by worn valve guides and/ or worn piston oil rings. This may be indicated by white exhaust smoke.

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

1. Gas leakage around the cylinder head - replace the damaged gasket and check and check the cylinder head warp.

2. Condition of the valve seating.

3. Valve clearance.

4. Piston/cylinder wear, piston seizure.

5. Piston ring, piston ring groove.

Page 62

4-10 ENGINE TOP END

Cylinder Head

Cylinder Head Assembly Removal

Remove:

•

Air Cleaner and Carburetor (see Fuel System chapter) Mufﬂer (see Mufﬂer Exhaust Pipe Removal) Intake Manifold (see Fuel System chapter) Spark Plug

Unscrew the rocker cover mounting bolts [A], and remove the cover

•

[B] and gasket.

When removing the #1, #2 cylinder head, set each cylinder at T.D.C

•

[A] of power stroke in.

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

•

CAUTION

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

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

•

head assembly.

NOTE



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

Cylinder Head Assembly Installation

Clean the mating surfaces of the cylinder heads and cylinder.

•

Install the push rods in their original positions on each cylinder. (see

•

Push Rod Installation). Install the knock pins.

•

Set each cylinder at T.D.C [A] of power stroke in.

•

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

•

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

NOTE



As the head gaskets are coated with sealing agents, be careful not to damage the surfaces.

Page 63

Cylinder Head

Tighten the cylinder head bolts following the tightening sequence.

•

Torque - Cylinder Head Bolts: 25 N1m (2.6 kg1m, 19.0 ft

CAUTION

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

Check and adjust the valve clearance.

•

Install the gasket and rocker cover.

•

Torque - Rocker Cover Mounting Bolts: 5.9 N

Install the other removed parts.

•

Push Rod Removal

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

•

Remove the rocker covers. (see Cylinder Head Assembly Removal)

•

Loosen the valve clearance adjusting nuts [A].

•

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

•

Pull out the push rods.

•

NOTE



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

m (0.6 kg

lb)

m, 52 in

ENGINE TOP END 4-11

lb)

Push Rod Installation

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

•

Install the push rods [A] in their original positions on each cylinder.

•



To Install the push rod in a correct position on the tappet [B], insert the push rod so end of the push rod is sliding down [C] along inside wall [D] of the crankcase and position the push rod end on to the tappet. Check that both intake and exhaustpush rods on each cylinder are at

•

lowest position on the cam lobes [E], if not turn the ﬂywheel clockwise one turn (360 Be sure the end of the push rods are correctly seated on the tappets.

•

Tighten the valve clearance adjusting nuts.

•

Check and adjust the valve clearance.

•



) and reset each cylinder at T.D.C of power stroke in.

Page 64

4-12 ENGINE TOP END

Cylinder Head

Push Rod Inspection

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

•

possible, and set a dial gauge on the rod at a point halfway between the blocks. Turn the rod to measure the runout. 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 Runout

Service Limit: 0.5 mm (0.02 in.)

Valve Mechanism Removal/Installation

Remove the cylinder head assembly. (see Cylinder Head Assembly

•

Removal)

NOTE



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

Remove:

•

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

Support the valve head in the combustion chamber with a suitable

•

block. To remove the collets [A], push down the valve retainer [B] with

•

thumbs and remove the Collets. Remove the spring [C] and valve [D] .

•

Remove the stem seals [A].

•

NOTE



It is not necessary to remove the stem seal unless it is being replaced.



Valve guide [B] is not replaceable, do no remove it.

Valve Installation.

•



Apply engine oil to the valve stem to avoid damaging the stem seal.



Check to see that the valve moves smoothly up and down in the guide.



Check the valve seating surface [A] between the valve [B] and valve seat [C]. Rocker Arm Installation

•



Soak the valve clearance adjusting nuts and rocker arm in the engine oil.



Install the rocker arm.

Page 65

Cylinder Head

Cleaning and Inspection

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

•

suitable tool [A]. To avoid gouging, use scrapers that are made of a material that will

•

not cause damage. Clean the head in a bath of high ﬂash-point solvent and dry it with

•

compressed air.

Clean the cylinder head in a well-ventilated area, and take care that there are no sparks or ﬂame anywhere near the working area; this includes any appliance with a pilot light. Do not use gasoline or a low ﬂash-point solvent to clean the cylinder head. A ﬁre or explosion could result.

Laya straightedge [A] across the mating surface of the head at several

•

different points, and measure warp by inserting a thickness gauge [B] between the straightedge and head. If warp exceeds the service limit, repair the mating surface. Replace the cylinder head if the mating surface is badly damaged.

Cylinder Head Warp

Service Limit: 0.05 mm (0.002 in.)

ENGINE TOP END 4-13

Check the cylinder head for cracks or other damage.

•

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

•

suspected area with mixture of 25% kerosene and 75% light engine oil. Wipe the area dry and immediately apply a coating of zinc oxide

•

dissolved in wood alcohol. If a cracks is present, the coating will become discolored at the defective area. If a cracks is present in the cylinder head, replace it.

•

Inspect the mating surface for burrs and nicks.

•

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

•

valve stem. If the contact points [A] are worn or damaged, replace the rocker arm.

Page 66

4-14 ENGINE TOP END

Valves

Valve Clearance Inspection

NOTE



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

Remove the rocker cover (see Cylinder Head Removal).

•

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

•

turning the crankshaft clockwise facing the ﬂywheel.

No.1 Cylinder:



The left projection [A] on the ﬂywheel is faced with the right leg [B] on the #1 ignition coil [C] as shown.



Check the intake and exhaust valvesare closed completely, if not turn the ﬂywheel one turn (360 the right leg again.

No.2 Cylinder:



The left projection [A] on the ﬂywheel is faced with the right leg [B] on the #2 ignition coil [C] as shown. Follow No.1 Cylinder alignment.



) clockwise and face the left projection with

Then check the valve clearance.

•



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

Valve Clearance (when cold)

Intake, Exhaust 0.075

Valve Clearance Adjustment

Since valve repairs change the valve clearance, adjust the valve

•

clearance to the speciﬁcation. Assemble the cylinder head and install the cylinder head assembly

•

on the block (see Cylinder Head Installation). Turn the crankshaft proper direction until the piston is at TDC of the

•

compression stroke (described above). Loosen the lock screws [A] and valve clearance adjusting nuts [B].

•

Insert a 0.07 mm (0.01 in.) thicIntrakness gauge [C] between the

•

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

Valve Clearance (when cold)

Intake, Exhaust: 0.075

0.125 mm (0.003 0.005 in.)

Holding the adjusting Nut with a spanner, tighten the lock screw to

•

the speciﬁed torque.

Torque - Valve Clearance Lock screws: 6.9 N1m (0.70 kg1m, 61 in1lb)

Do not overtighten.

•

Remeasure any clearance that was adjusted. Readjust if necessary.

•

Page 67

Valves

Valve Seat Inspection

Remove the valve. (see Valve Mechanism Removal/Installation)

•

Inspect the valve seats for damage.

•

If the seats are warped or distorted beyond reconditioning, replace the cylinder head. Pitted or worn valve seats can be refaced. Lap the valves to the seats

•

after refacing. Coat the valve seat with machinist’s dye.

•

Push the valve into the guide.

•

Rotate the valve against the seat with a lapping tool.

•

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

•

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

NOTE



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

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

Valve Seating Surface Width (STD)

[FH451V, FH500V, FH531V]

Inlet, Exhaust 0.6 [FH601V, FH641V, FH680V, FH721V]

Inlet 0.8

Exhaust 1.1

0.9 mm (0.024 0.035 in.)

1.4 mm (0.03 0.05 in.)

1.6 mm (0.04 0.06 in.)

ENGINE TOP END 4-15

Valve Seat Repair

Follow the manufacture’s instructions for use of valve seat cutters

•

Special Tools

Intake Valve: Seat Cutter 45

Outside Cutter 30 Exhaust Valve: Seat Cutter 45 Outside Cutter 30 Valve Seat Cutter Holder-ø6.0: 57001-1360 Valve Seat Cutter Holder Bar: 57001-1128

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



- ø35.0 57001-1116



- ø33.0 57001-1199



- ø30.0 57001-1187



- ø30.0 57001-1120

Page 68

4-16 ENGINE TOP END

Valves

Seat Cutter Operating Cares:

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

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

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

NOTE



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

4. Setting the valve seat cutter holder [A] in position, operate the cutter [B] with one hand [C]. Do not apply too much force to the diamond portion.

NOTE



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

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

Marks Stamped on the Cutter:

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

1 Cutter number, selected from 1 to 12



37.5 Cutter diameter of cutter [B] KS8B Manufactured lot number

Cutter angle [A]

Operating Procedures:

Clean the seat area carefully.

•

Recondition the valve seats with the valve seat cutters (45

•

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

•

dye. Measure the seat width [A]. If it is more than the STD width, the

•

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

•

Coat the seat with machinist’s dye.

•

Fit a 45cutter [A] to the holder and slide it into the valve guide.

•



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



,30) and

CAUTION

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

Page 69

Valves

Use a 30seat cutter [A] to narrow the seat width to the STD width.

•



Turn the seat cutter one turn at a time while pressing down very lightly. Check the seat width after each turn.

CAUTION

The 30cutter removes material very quickly. Check the seat width frequently to prevent over grinding.

NOTE



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

Make a light pass with the 45

•

the edge of the seat. After resurfacing the seat, inspect for even valve seating.

•



Apply a machinist’s dye to the valve face, insert the valve, and snap it closed against the seat several times. The valve surface should show good contact all the way around. Be sure the valve seat is centered on the valve face. The position of the valve in the seat is evident after lapping the valve. If the seat does not make proper contact, lap the valve into seat with a vacuum cap tool.

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

•

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

•

valve in a circular motion to lap the valve to the seat. Lift the valve slightly from the seat every 8 to 10 strokes, continue

•

lapping operation until a uniform ring appears around entire surface of the valve face.



cutter to remove any possible burrs at

ENGINE TOP END 4-17

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

•

lapping compound. Dry the parts thoroughly. Note the position of the lapping mark on the valve face. The lapping

•

mark should appear on or near the center of the valve face. When the engine is assembled, be sure to adjust the valve clear-

•

ances. (see Valve Clearance Adjustment)

Valve Head Thickness

Remove the valve (see Valve Mechanism Removal/Installation).

•

Measure the thickness of the valve head.

•

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

Valve Head Thickness

Service Limit (IN, EX): 0.35 mm (0.014 in)

Page 70

4-18 ENGINE TOP END

Valves

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 the valve.

Valve Stem Runout

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

Valve Stem Diameter

Measure the diameter of the valve stem [A] in two directions at right

•

angles, at four different positions on the stem. If any single measurement is less than the service limit, replace the valve.

Valve Stem Diameter

Service Limit: Intake: 5.95 mm (0.234 in.) Exhaust: 5.93 mm (0.233 in.)

Valve Guide Inside Diameter

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

•

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

Valve Guide Inside Diameter

Service Limit: Intake, Exhaust 6.08 mm (0.239 in.)

Valve Spring Inspection

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

•

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

•

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

Valve Spring Free Length

Service Limit: 31.0 mm (1.22 in.)

Page 71

Cylinder, Piston

Piston Removal

Split the crankcase (see Camshaft/Crankshaft chapter).

•

Remove the camshaft (see Camshaft/Crankshaft chapter).

•

Turn the crankshaft to expose the connecting rod cap bolts [A].

•

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

•

NOTE



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

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

•

connecting rod out of the cylinder.

CAUTION

Note a location of the arrow match mark [A] on the piston head in relation to K Mark [B] on the connecting rod. No.1 cyl. K Mark on the connecting rod is face to face with No.2 cyl. K Mark on the connecting rod. Keep parts together as a set.

ENGINE TOP END 4-19

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

•

[B].

Remove the piston by pushing the piston pin [A] out the side from

•

which the snap ring was removed.

Remove the top and second rings with piston ring pliers.

•

Special Tool - Piston Ring Pliers: 57001–115

If the special tool is not available, carefully spread the ring opening

•

with your thumbs and then push up on the opposite side of the ring [A] to remove it. Remove the 3-piece oil ring with your thumbs in the same manner.

•

Page 72

4-20 ENGINE TOP END

Cylinder, Piston

Piston Installation

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

•

expander ends [B] touch together, never overlap. Install the upper and lower steel rails. There is no UP or Down to the

•

rails. They can be installed either way.

Do not mix up the top and second rings.

•

Install the second and top rings as shown.

•

The rings should turn freely in the grooves.

[A] Piston Head [B] Top Ring for F [C] Second Ring for FH451V, 500V, 531V [D] Top Ring for FH601V, 641V, 680V, 721V [E] Second Ring for FH601V, 641V, 680V, 721V

H451V,500V,531V

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

•

[A]. Arrow Match Marks [B]. Top ring End Gap, Upper Steel Rail End Gap



[C]. 30 [D]. Second Ring End Gap, Lower Steel Rail End Gap

Apply engine oil to the piston pins.

•

Assemble the pistons onto the connecting rods as follow: No.1 cyl. Piston, align the arrow match mark on the piston head with

opposite the raised letters (K Mark) on the connecting rod.

No.2 cyl. piston, align the arrow match mark on the piston head with

K Mark on the connecting rod.

[A]. No.1 Cyl. Piston [B]. No.2 Cyl. Piston [C]. Arrow Match Marks [D]. K Mark [E]. Opposite K Mark

When installing a piston pin snap ring, compress it only enough to

•

install it and no more. Fit a new piston pin snap ring into the side of the piston so that the ring opening [A] does not coincide with the notch [B] in the edge of the piston pin hole.



CAUTION

Do not reuse the snap rings, as removal weakens and deforms

them. They could fall out and score the cylinder wall.

Page 73

Cylinder, Piston

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

•

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

Special Tool - Piston Ring Compressor Grip: 57001–1095

Piston Ring Compressor Belt: 57001–1097

Insert the piston and connecting rod so that the arrow match mark

•

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

ENGINE TOP END 4-21

CAUTION

The connecting rod and the connecting rod big end cap are machined at the factory in the assembled state, so they must be replaced together as a set.

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

•

[B] and caps [C]. Install the connecting rod big end caps on their original position on

•

each connecting rod big ends. Apply a small amount of engine oil to the thread [D] and seating

•

surface [E] of the cap bolts. Tighten the cap bolts.

•

Torque - [FH451V, 500V, 531V]

Connecting Rod Big End Cap Bolts: 5.9 N

lb) [FH601V, 641V, 680V, 721V] Connecting Rod Big End Cap Bolts: 21 N

lb)

Install:

•

Camshaft (see Camshaft/Crankshaft chapter)

•

Crankcase Cover (see Camshaft/Crankshaft chapter)

•

Piston/Cylinder Seizure

In case of seizure, remove the piston.

•

Visually inspect the cylinder and piston damage.

•

If there is only light damage, smooth the position with #400 emery cloth. Remove the small aluminum deposits from the cylinder with #400 emery cloth or light honing. If the damage is severe, the both cylinders must be bored oversize and oversized pistons installed.

m (0.60 kg1m, 52

m (2.1 kg

m, 15

Page 74

4-22 ENGINE TOP END

Cylinder, Piston

Piston Cleaning

Remove the piston and piston rings (see Piston Removal).

•

CAUTION

Never clean the piston head with the engine assembled. Carbon particles will fall between the piston and cylinder, and damage the crankshaft bearings.

Scrape the carbon off [A] the piston head.

•

Use the scraping tools carefully. Do not gouge the piston head. To

•

avoid gouging, use scrapers that are made of a material that will not cause damage. Clean the piston ring grooves [A] with a broken piston ring or other

•

suitable tools.

CAUTION

Be careful not to widen the ring grooves. Damaged ring 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, replace them. If the ring grooves are worn unevenly or damaged, replace both the piston and piston rings. Check ring grooves for wear by inserting a new ring in the proper

•

groove at several points around the piston. Measure the clearance between the top and second rings and their

•

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

Piston Ring/Groove Clearance

Service Limit

FH451V, FH500V, FH531V FH601V, FH641V, FH680V,

Top 0.15 mm (0.006 in.) 0.18 mm (0.007 in.) Second 0.12 mm (0.005 in.) 0.16 mm (0.006 in.)

NOTE



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

FH721V

Page 75

Cylinder, Piston

Measure the piston ring thickness [A].

•



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

Piston Ring Thickness

Service Limit

Top, Second 1.40 mm (0.055 in.)

NOTE



When using new rings in a used piston, check for uneven groove wear. The rings should ﬁt perfectly parallel to the groove sides. If not, replace the piston.

Piston Ring End Gap

Remove the piston rings.

•

Push each ring (one at a time) in the cylinder bore to a point close

•

to the bottom of the cylinder bore.



Use the piston to push it in to be sure it is square. Measure the gap [A] between the ends of the ring [B] with a thickness

•

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

Piston Ring End Gap

Service Limit

FH451V, FH500V, FH531V FH601V, FH641V, FH680V,

Top 0.70 mm (0.028 in.) 0.65 mm (0.026 in.) Second 0.78 mm (0.031 in.) Oil 1.05 mm (0.041 in.)

FH721V

ENGINE TOP END 4-23

Piston Pin, Piston Pin Hole, and Connecting Rod Wear

Remove the piston pin.

•

Measure the diameter of the piston pin with a micrometer at several

•

points. If the outside diameter is less than service limit, replace the piston pin.

Piston Pin Outside Diameter

Service Limit: 15.96 mm (0.628 in.)

Measure the inside diameter [A] of the piston pin hole at severalpoints

•

on both side. Use a dial bore gauge. If the inside diameter is more than the service limit, replace the piston.

Piston Pin Hole Inside Diameter

Service Limit: 16.08 mm (0.633 in.)

Page 76

4-24 ENGINE TOP END

Cylinder, Piston

Measure the inside diameter [A] of the small end of the connecting

•

rod at several points. Use a dial bore gauge. If the inside diameter is more than the service limit, replace the connecting rod.

Connecting Rod Small End Inside Diameter

Service Limit: 16.05 mm (0.632 in.)

Piston Diameter

Measure the outside diameter of the piston 12.5 mm (0.9 in.) up from

•

the bottom of the piston at a right angle to the direction of the piston pin hole. If the measurement is less than the service limit, replace the piston.

Piston Diameter

Model Service Limit FH451V, FH500V, FH531V 67.79 mm (2.669 in.) FH601V, FH641V, FH680V, FH721V 74.99 mm (2.952 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 than the service limit, the cylinder must be bored to the next oversize and then honed (see Cylinder Boring and Honing).

Cylinder Inside Diameter

Model Item standard Service

FH451V, Standard Cylinder 67.98 68.00 mm 68.10 mm FH500V, (2.676 2.677 in.) (2.681 in.) FH531V 0.5 mm Oversize 68.48 68.50 mm 68.60 mm

Cylinder (2.696 2.697 in.) (2.701 in.) FH601V, Standard Cylinder 75.18 75.20 mm 75.28 mm FH641V, (2.960 2.961 in.) (2.964 in.) FH680V, 0.5 mm Oversize 75.68 75.70 mm 75.78 mm FH721V Cylinder (2.979 2.980 in.) (2.983 in.)

Cylinder Bore Out-of-Round

Standard: 0.01 mm (0.004 in.) Service Limit: 0.056 mm (0.0022 in.)

Limit

Page 77

Cylinder, Piston

Cylinder Boring and Honing

Always resize to exactly 0.5 mm (0.02 in.) over the standard bore

size.

If this is done accurately, the stock oversize rings and piston will ﬁt

perfectly and proper clearance will be maintained.

Resizing the cylinder bore can be done by reliable repair shop or by

using a drill press and honing tool.

Use the stone recommended by the hone manufactures to produce

correct cylinder wall ﬁnish.

Machine-bore ﬁrst, the bore diameters should be shown in the table.

Final Boring Bore Diameter

Fine Boring Bore DiameterOversize

FH451V, 500V, 531V FH601V, 641V, 680V, 721V

0.50 mm

Final Bore Diameter

68.46 (2.695

FH451V, 500V, 531V FH601V, 641V, 680V, 721V

68.48 68.50 mm 75.68 75.70 mm0.50 mm (2.696 2.697 in.) (2.979 2.980 in.)

68.48 mm

2.696 in.)

75.65 (2.978

Final Bore DiameterOversize

75.68 mm

2.979 in.)

ENGINE TOP END 4-25

Change to a honing stone for ﬁnishing, the ﬁnal bore diameter should be as shown in the table. Be sure the correct stone is used and the stone is not worn.

Clean the cylinder at the top and bottom of the cylinder to remove

•

burns and pieces of the base and head gasket. Anchor the cylinder (block) on the drill press table before honing.

•

Align the center of the cylinder bore to the press center. Set the press

•

to operate from 200 to 250 rpm. Connect the drive shaft to the hone and set the stop on the drill press

•

so the hone can only extend 20 to 25 mm (3/4 to 1.0 in.) above the top or below the bottom of the cylinder liner. Rotate the adjusting nut (knob) on the hone until the stones contact

•

snugly against the cylinder wall at the narrowest point. “Do not Force”. Turn the stone by hand. If you cannot turn it, the stone is too tight.

•

Loosen the hone until it can be turned by hand. Be sure that the cylinder and hone are centered and aligned with the

•

drive shaft and drill spindle. Pour honing oil inside of the cylinder during the honing operation.

•

Start the drill press. Move the hone up and down in the cylinder approximately 20 cycles-per-minute. Check the diameter of thecylinder bore regularly during honing, using

•

an inside micrometer.

Page 78

4-26 ENGINE TOP END

Cylinder, Piston

CAUTION

Stop the drill press before measuring and remove the hone from the cylinder.

NOTE



The ﬁnish should not be smooth, but have a 40 to 60 degree crosshatch pattern.

Hone the cylinder until it is about 0.007 to 0.009 mm (0.0003 to 0.0004

•

in) large to allow for shrinkage when the cylinder cools.

NOTE



Do not use gasoline, kerosene, or commercial solvent to clean the cylinder bore. These ﬂuids only wash all the oil from the cylinder wall. They do not remove the metal particles produced during honing.

Clean the cylinder thoroughly. Use soap warm water and clean rags.

•

Clean the cylinder wall for “white glove” inspection. A clean white rag should not show soil from the cylinder wall. Dry the cylinder and coat with a engine oil.

•

CAUTION

The cylinder must be thoroughly cleaned after honing to eliminate all grit.

Page 79

Mufﬂer/Exhaust Pipe Installation

Mufﬂer/Exhaust Pipe Removal

Loosen the clamp nut [A].

•

Remove the bolt [B] on the mufﬂer bracket and take off the mufﬂer.

•

Unscrew the exhaust pipe ﬂange nuts [A], and remove the exhaust

•

pipe [B] with pipe cover [C]. Use a penetrating oil if necessary to break threads loose. Remove the gaskets.

•

Unscrew the hook nut [D], separate the exhaust pipe and pipe cover.

•

Do not use unnecessary force on the exhaust pipes when removing

•

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

ENGINE TOP END 4-27

Mufﬂer/Exhaust Pipe Installation

Clean the exhaust pipe ﬂanges to the exhaust port gasket surfaces

•

and install a new gaskets each time the mufﬂer installed. Install the gasket.

•

To prevent mis-threading, ﬁngertight the ﬂange nuts ﬁrst. Next tighten

•

the hook nut. Tighten the nuts.

•

Torque - Exhaust Pipe Flange Nuts: 15 N1m (1.5 kg1m, 11 ft

Install the mufﬂer.

•

After installation, thoroughly warm up the engine, wait until the engine

•

cools down and retighten the bolts and nuts.

Inspection

Inspect the exhaust pipe or mufﬂer for dents, cracks, rust and holes.

•

If the exhaust pipe or mufﬂer is damaged, it should be replaced for best performance and least noise. Check the mufﬂer for distortion and/or loose internal components.

•

Loss of power could develop if the mufﬂer loose the internal components restricting the exhaust ﬂow. Check for breaks in the seams and check weld at the junction of the

•

exhaust pipes and mufﬂer. Tap the mufﬂer with a plastic hammer to decarbonize.

•

lb)

Page 80

Page 81

LUBRICATION SYSTEM 5-1

Lubrication System

Table of Contents

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

Engine Oil Flow Chart........................................................................................................................................................5-4

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

Engine Oil, Oil Filter, and Oil Cooler..................................................................................................................................5-6

Oil Level Inspection.....................................................................................................................................................5-6

Oil Change...................................................................................................................................................................5-6

Oil Filter Removal........................................................................................................................................................5-7

Oil Filter Installation.....................................................................................................................................................5-7

Oil Cooler Removal.....................................................................................................................................................5-7

Oil Cooler Installation..................................................................................................................................................5-7

Pressurized Lubrication System.........................................................................................................................................5-8

Oil Pressure Measurement..........................................................................................................................................5-8

Oil Pressure Switch Inspection...................................................................................................................................5-8

Oil Pump, Relief Valve........................................................................................................................................................5-9

Oil Pump, Relief Valve Removal.................................................................................................................................5-9

Oil Pump, Relief Valve Installation..............................................................................................................................5-9

Oil Pump, Relief Valve Inspection...............................................................................................................................5-9

Oil Screen.........................................................................................................................................................................5-12

Oil Screen Removal...................................................................................................................................................5-12

Oil Screen Installation...............................................................................................................................................5-12

Cleaning and Inspection............................................................................................................................................5-12

Page 82

5-2 LUBRICATION SYSTEM

Exploded View

Page 83

Exploded View

[FH451V, FH500V, FH531V]

T1: 3.9 N T2: 6.9 N T3: 9.8 N T4: 20 N T5: 39 N T6: 17 N T7: See the text T8: 5.9 N

[FH601V, FH641V, FH680V, FH721V]

T1: 3.9 N T2: 6.9 N T3: 9.8 N T4: 20 N T5: 39 N T6: 17 N T7: See the text T8: 5.9 N T9: 44 N

O: Apply engine oil.

SS: Apply silicone sealant.

m (0.40 kg

m (0.7 kg

m (1.0 kg

m (2.0 kg

m (4.0 kg

m (1.7 kg

m (0.6 kg

m (0.40 kg

m (0.7 kg

m (1.0 kg

m (2.0 kg

m (4.0 kg

m (1.7 kg

m (0.6 kg

m (4.5 kg

m, 35 in

m, 61 in1lb)

m, 87 in1lb)

m, 14.5 ft

m, 29 ft

m, 12.0 ft

1 1

m, 14.5 ft

m, 29 ft

m, 12.0 ft1lb)

m, 33 ft

lb)

m, 52 in

m, 35 in1lb) m, 61 in m, 87 in

lb)

m, 52 in

lb)

1 1

lb)

lb) lb)

lb)

lb) lb)

lb)

LUBRICATION SYSTEM 5-3

Page 84

5-4 LUBRICATION SYSTEM

Engine Oil Flow Chart

Page 85

Speciﬁcations

LUBRICATION SYSTEM 5-5

Item

Engine Oil:

Grade SF, SG, SH or SJ class Viscosity SAE40, SAE30, SAE10W-30 / SAE10W-40, or SAE5W-20 Capacity [When ﬁlter is not removed] 1.5 L (1.6 US qt)

[When ﬁlter is removed]

1.7 L (1.8 US qt)

1.8 L (1.9 Us-qt)

Level Operating range (grid area) on dipstick Oil Pressure 241 to 310 kPa (35 to 45 psi) Oil Pressure Switch:

Detect pressure 98 kPa (14.2 psi)

Screw PT 1/8 pipe thread Oil Filter By-pass Valve Openning

Pressure 78.5

Item

Oil Pump:

Inner and outer rotor clearance 0.2 mm (0.008 in.)

Outer rotor outside diameter 40.470 mm (1.5933 in.)

Outer rotor thickness 9.830 mm (0.3870 in.)

Pump housing inside diameter 40.801 mm (1.6063 in.)

Pump housing depth 10.230 mm (0.4028 in.)

Pump shaft outside diameter 10.923 mm (0.4300 in.)

Pump shaft bearing inside diameter 11.072 mm (0.4359 in.)

Relief valve spring free length 19.50 mm (0.77 in.)

117.5 kPa (11.4 17.1 psi)

111

Standard

except FH721V

FH721V

Service Limit

Special Tool - Oil Filter Wrench : 57001–1249 Sealant - Kawasaki Bond (Silicone Sealant) : 56019–120

Page 86

5-6 LUBRICATION SYSTEM

Engine Oil, Oil Filter, and Oil Cooler

CAUTION

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

Fill fresh engine oil to the speciﬁed level (see Oil Level Inspection).

•

Run the engine at slow speed 2 minutes.

•

Stop the engine and check the oil level.

•

Oil Level Inspection

Place the engine on a level surface.

•

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

•

cloth. Insert the dipstick into tube [C] without screwing it in, then check the

•

oil Level. The oil level should be the operating range [D] (grid area) on the

•

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

CAUTION

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



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

NOTE



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

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

Oil Change

Change the oil after ﬁrst 8 hours of operation. Thereafter change oil

•

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

•

engine. Place the engine on a level surface.

•

Place a suitable container under the engine.

•

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

•

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

Check the O-ring [B] at the drain plug for damage. Replace the O-

•

ring with a new one if it is damaged. If the oil drain plug joint is removed, tighten it.

Torque - Oil Drain Plug Joint (Plastic) :17 N1m (1.7 kg1m, 12.0 ft1lb)

Oil Drain Plug Joint (Metal) :39 N

Install the drain plug with the O-ring and tighten it.

•

Torque - Oil Drain Plug (Plastic) : 6.9 N1m (0.7 kg1m, 61 in1lb)

Oil Drain Plug (Metal) : 20 N

m (4.0 kg1m, 29 ft1lb)

m (2.0 kg1m, 14.5 ft1lb)

Page 87

Engine Oil, Oil Filter, and Oil Cooler

Remove the oil ﬁller cap and pour in the speciﬁed type and amount

•

of oil.

Engine Oil :

Grade: SF, SG, SH or SJ Class Viscosity: SAE40, SAE30, SAE10W-30/SAE10W-40, or

Capacity: [When ﬁlter is not removed]



Some increase in oil consumption may be expected when a multi grade engine oil (10W-30/10W-40, 5W-20) is used. Check the oil level frequently.

Oil Filter Removal

Using a strap wrench or oil ﬁlter wrench [A], remove the oil ﬁlter [B].

•

Special Tool - Oil Filter Wrench : 57001–1249



When unscrewing the oil ﬁlter, place a suitable container beneath the oil drip tray to receive oil from the oil ﬁlter and oil passages in the engine. Turn the ﬁlter counterclockwise to remove it

SAE5W-20

1.5 L (1.6 US qt) [When ﬁlter is removed]

1.7 L (1.8 US qt)

1.8 L (1.9 US qt)

111 111

NOTE

except FH721V. FH721V.

LUBRICATION SYSTEM 5-7

Oil Filter Installation

Apply light ﬁlm of engine oil to the seal [A].

•

Install new ﬁlter.

•



Turn the ﬁlter until the seal contacts mounting surface [B] of the engine. Then turn the ﬁlter BY HAND (S) 3/4 turn more. Run the engine at slow idle speed 2 minutes. Check for leaks around

•

the engine. Stop the engine. Check the oil level (see Oil Level Inspection).

•

Oil Cooler Removal

Remove the oil ﬁlter (see Oil Filter Removal).

•

Unscrew the mounting joint [A] and remove the oil cooler [B].

•

Check the O-ring [C] in groove of the oil cooler for damage.

•

Replace the O-ring with a new one, if necessary.

Oil Cooler Installation

Install the oil cooler with the mounting joint and tighten it.

•

Torque - Oil Cooler Mounting Joint: 44 N

Install the oil ﬁlter (see Oil Filter Installation).

•

m (4.5 kg1m, 33 ft1lb)

Page 88

5-8 LUBRICATION SYSTEM

Pressurized Lubrication System

The engine lubrication circuit is a pressurized system consisting of a positive displacement pump which picks up oil through a ﬁlter screen from the crankcase. The oil is pumped to a replaceable oil ﬁlter cartridge, through the engine’s oil passages to lubricate internal components, and return to the crankcase. A pressure relief valve is used between the oil pump and oil ﬁlter to relieve excessive oil pressure by returning excess oil to the crankcase (see Oil Flow Chart).

Oil Pressure Measurement

Remove the oil pressure switch or oil passage plug from the

•

crankcase. Install an appropriately sized oil pressure gauge adapter [A] and oil

•

pressure gauge [B]. Run the engine and allow warm up completely.

•

Run the engine at fast idle speed and read the oil pressure gauge.

•

Stop the engine.

•

Remove the oil pressure gauge and adapter.

•

Apply silicone sealant to the threads of the pressure switch and

•

tighten it, or tighten the plug.

Sealant - Kawasaki Bond (Silicone Sealant) : 56019–120 Torque - Oil Pressure Switch : 9.8 N

Oil Passage Plug : 3.9 N

If the oil pressure is below the speciﬁcation, inspect the oil pump and relief valve. If the oil pump and relief valve are not at fault, inspect the rest of the lubrication system.

Oil Pressure

241 to 310 kPa (35 to 45 psi)

m (1.0 kg

m (0.40 kg

m, 87 in

m, 35 in

lb)

Oil Pressure Switch

PT 1/8 (Taper Pipe Threads)

Oil Pressure Switch Inspection

When the oil pressure falls below 98 kPa (14.2 psi), the oil pressure switch activates the oil warning lamp to alert the operator or lubricating problem.

To check the oil warning system, insert the switch key into the “OFF”

•

position of the engine switch, then turn it to the “RUN” position. The

warning light must be illuminated.

When the engine is running be sure the warning light is “OFF”.

•

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

the oil level.

When starting the engine, note the warning light on dash carefully.

•

If the warning light is on in the started engine in spite of adequate oil

level, check the lead from the pressure switch to the warning light for

short circuit and/or check the pressure switch and replace damaged

part.

If the light is not on at the moment of the engine switch operation,

check all leads of the warning light circuit or bulb and replace

damaged parts.

Page 89

Oil Pump, Relief Valve

Oil Pump, Relief Valve Removal

Remove the crankcase cover (see Camshaft/Crankshaft chapter).

•

Unscrew the mounting bolts and remove the oil pump parts assembly

•

(pump gear, pump cover plate, pump shaft, pins and rotors). Take off the relief valve spring and ball.

•

Disassemble the pump parts assembly.

•

[A] Pin [B] Pump Gear [C] Mounting Bolts [D] Outer Rotor [E] Inner Rotor [F] Pump Shaft [G] Relief Valve Ball [H] Spring [I] Pump Cover Plate [J] 6 mm DIA Hole

Oil Pump, Relief Valve Installation

Fill the rotor housing with engine oil for initial lubrication.

•

Install the relief valve ball and spring in position, then install the pump

•

parts assembly in the crankcase cover.

NOTE



When Installing the pump parts assembly, align the 6 mm DIA hole [A] on the cover plate with center of the relief valve.

Install the mounting bolts and tighten them.

•

Torque - Oil Pump Cover Plate Mounting Bolts : 5.9 N1m (0.6 kg

lb)

m, 52

LUBRICATION SYSTEM 5-9

Oil Pump, Relief Valve Inspection

Remove the oil pump (see Oil Pump, Relief Valve Removal).

•

Visually inspect the pump gear, outer and inner rotor, and cover plate.

•

If there is any damage or uneven wear, replace them.



Check the clearance [A] between the inner and outer rotor with a feeler gauge. Measure the clearance between the high point of the inner rotor and the high point of the outer rotor. If the measurement exceed the service limit, replace the rotors as a set.

Inner and Outer Rotor Clearance

Service Limit: 0.2 mm(0.008 in.)

Measure the outside diameter [A] of the outer rotor with a micrometer

•

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

Outer Rotor Outside Diameter

Service Limit: 40.470 mm(1.5933 in.)

Measure the thickness [B] of the outer rotor with a micrometer at

•

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

Outer Rotor Thickness

Service Limit: 9.830 mm (0.3870 in.)

Page 90

5-10 LUBRICATION SYSTEM

Oil Pump, Relief Valve

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

•

micrometer at several points.

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

crankcase cover.

Pump Housing Inside Diameter

Service Limit: 40.801 mm (1.6063 in.)

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

•

at several points.

If any of measurement is more than the service limit, replace the

crankcase cover.

Pump Housing Depth

Service Limit: 10.230 mm (0.4028 in.)

Measure the outside [A] diameter of the pump shaft with a micrometer

•

at several points.

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

Pump Shaft Outside Diameter

Service Limit: 10.923 mm (0.4300 in.)

Measurer the inside diameter [A] of the pump shaft bearing in the

•

crankcase cover with a inside micrometer at several points.

If the inside diameter is more than the service limit replace the

crankcase cover.

Pump Shaft Bearing Inside Diameter

Service Limit: 11.072 mm (0.4359 in.)

Visually inspect the relief valve spring, steel ball and valve seat in the

•

crankcase cover.

If any rough spots are found during above inspection, wash the valve

clean with a high ﬂash-point solvent and blowout any foreign particles

that may be in the valve with compressed air.

Clean the parts in a well ventilated area, and take care that

there is no spark or ﬂame anywhere near the working areas.

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

gasoline or low ﬂash-point solvents.

Page 91

Oil Pump, Relief Valve

If cleaning does not solve the problem, replace the relief valve parts. If necessary, put the ball in position and lightly tap the ball with a suitable tools to form a perfect seat. Measure free length [A] of the spring with a vernier caliper.

•

If the free length of the spring is less than the service limit, replace the spring.

Relief Valve Spring Free Length

Service Limit: 19.50 mm (0.77 in.)

LUBRICATION SYSTEM 5-11

Page 92

5-12 LUBRICATION SYSTEM

Oil Screen

Oil Screen Removal

Remove the crankcase cover (see Camshaft/Crankcase chapter).

•

Unscrew the mounting bolts [A] and remove the oil pump parts

•

assembly.

Remove the oil screen [B].

•

Oil Screen Installation

Clean the oil screen thoroughly whenever it is removed for anyreason.

•

Insert the oil screen [A] in position and install the oil pump parts

•

assembly (see Oil Pump, Relief Valve Installation).

Cleaning and Inspection

Clean the oil screen with high ﬂash-point solvent and remove any

•

particles stuck to it.

Clean the screen in a well-ventilated area, and take care that

there is no spark or ﬂame anywhere near the working area.

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

gasoline or low ﬂash-point solvents.

NOTE



While cleaning the screen, check for any metal particles that might indicate internal engine damage.

Check the screen carefully for any damage: holes and broken wire.

•

If the screen is damaged, replace it.

Page 93

CAMSHAFT/CRANKSHAFT 6-1

Camshaft/Crankshaft

Table of Contents

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

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

Crankcase..........................................................................................................................................................................6-5

Crankcase Cover Removal..........................................................................................................................................6-5

Crankcase Cover Installation.......................................................................................................................................6-5

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

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

Breather..............................................................................................................................................................................6-8

Breather Element Removal - FH451V, 500V, 531V....................................................................................................6-9

Breather Element Installation - FH451V, 500V, 531V.................................................................................................6-9

Breather Valve Inspection - FH601V, 641V, 680V, 721V ...........................................................................................6-9

Camshaft, Tappet.............................................................................................................................................................6-10

Camshaft, Tappet Removal.......................................................................................................................................6-10

Camshaft, Tappet Installation....................................................................................................................................6-10

Camshaft Disassembly..............................................................................................................................................6-11

Camshaft Assembly...................................................................................................................................................6-11

Camshaft Inspection..................................................................................................................................................6-11

Camshaft Bearing/Journal Wear...............................................................................................................................6-11

Crankshaft, Connecting Rod............................................................................................................................................6-13

Connecting Rod Removal..........................................................................................................................................6-13

Connecting Rod Installation......................................................................................................................................6-13

Crankshaft Removal..................................................................................................................................................6-13

Crankshaft Installation...............................................................................................................................................6-13

Cleaning/Inspection ..................................................................................................................................................6-13

Connecting Rod Bend/Twist......................................................................................................................................6-13

Connecting Rod Big End/Crankpin Width Wear.......................................................................................................6-14

Connecting Rod Big End Bearing/Crankpin Wear....................................................................................................6-14

Crankshaft Runout.....................................................................................................................................................6-15

Crankshaft Main Journal/Wear..................................................................................................................................6-15

Crankpin Resizing.....................................................................................................................................................6-16

Page 94

6-2 CAMSHAFT/CRANKSHAFT

Exploded View

Page 95

Exploded View

[FH451V, FH500V, FH531V]

T1: 5.9 N T2: 25 N T3: See Engine Top End chapter.

[FH601V, FH641V, FH680V, FH721V]

T1: 5.9 N T2: 25 N T3: See Engine Top End chapter.

O: Apply engine oil. G: Apply grease.

SS: Apply silicone sealant.

S: Follow the speciﬁc tightening sequence.

[FH601V, FH641V, FH680V, FH721V]

1. Screw

2. Plate

3. Valve B: Sealant bead on crankcase side of gasket.

m (0.6 kg

m (2.6 kg

m (0.6 kg

m (2.6 kg

m, 52 in

m, 19.0 ft1lb)

m, 52 in

m, 19.0 ft

lb)

CAMSHAFT/CRANKSHAFT 6-3

Page 96

6-4 CAMSHAFT/CRANKSHAFT

Speciﬁcations

Item

Camshaft, Tappet:

Cam lobe height Intake

Exhaust 29.131 mm (1.1469 in.) 29.621 mm (1.166 in.)

Camshaft journal diameter PTO side 15.985 mm (0.6293 in.)

Flywheel side 15.985 mm (0.6293 in.)

Camshaft bearing inside diameter Crankcase 16.136 mm (0.6352 in.)

Crankcase cover 16.136 mm (0.6352 in.)

Crankshaft, Connecting Rod:

Connecting rod bend 0.15/100 mm

Connecting rod twist 0.15/100 mm

Connecting rod big end width 18.80 mm (0.74 in.) 19.90 mm (0.783 in.) Crankpin width 39.50 mm (1.56 in.) 43.1 mm (1.697 in.) Connecting rod big end inside diameter 35.055 mm (1.3801 in.) 38.055 mm (1.498 in.) Crankpin Outside diameter 34.94 mm (1.3756 in.) 37.94 mm (1.494 in.) Crankshaft runout 0.05 mm (0.002 in.) TIR Crankshaft journal diameter PTO side 34.90 mm (1.374 in.) 39.896 mm (1.571 in.)

Flywheel side 34.93 mm (1.375 in.) 39.896 mm (1.571 in.)

Crankcase:

PTO shaft bearing inside diameter

Crankcase Cover 35.15 mm (1.384 in.) 40.15 mm (1.581 in.)

Crankshaft journal bearing inside diameter

Crankcase 35.15 mm (1.384 in.) 40.15 mm (1.581 in.)

FH451V, 500V, 531V FH601V, 641V, 680V, 721V

29.131 mm (1.1469 in.) 29.621 mm (1.166 in.)

(0.006/3.94 in.)

Service Limit

Sealant - Kawasaki Bond (Silicone Sealant): 56019–120

Page 97

Crankcase

Crankcase Cover Removal

Set the engine on a clean surface while parts are being removed.

•

Drain the oil (see Lubrication System chapter).

•

Remove:

•

Exhaust Pipe and Mufﬂer (see Engine Top End chapter) Control Panel (see Fuel System chapter) Governor Arm (see Fuel System chapter)

Unscrew the mounting bolts [A] and remove the crankcase cover [B]

•

from the crankcase.



There are two knock pins on the crankcase mating surface. A wooden or plastic mallet may be used to gently tap loose the crankcase cover.

Crankcase Cover Installation

Chip off the old gasketfrom the mating surfaces of the crankcase and

•

cover. Using compressed air, blow out the oil passage in the crankcase

•

cover. With a high ﬂash-point solvent, clean off the mating surfaces of the

•

crankcase and cover, and wipe dry.

Clean the crankcase and cover in a well-ventilated area, and take care that there are no sparks or ﬂame anywhere near the working area; this includes any appliance with a pilot light. Do not use gasoline or a low ﬂash-point solvent to clean parts. A ﬁre or explosion could result.

CAMSHAFT/CRANKSHAFT 6-5

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

•



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



Pack some amount of a high temperature grease [B] into the space between the seal lip [C] and dust lip [D]. Press in the new oil seal using a press or suitable tools until it is ﬂush with ﬂange surface [E]. Do not damage the seal lips.

When replacing the oil seal [A] of the governor shaft, note the

•

following.



Install the oil seal into the crankcase cover [B] after the governor shaft is inserted in the cover, and so that the marks [C] face out.



The depth is 0 When installing the governor shaft and plate in the crankcase cover,

•

see Fuel System chapter.

1mm(0 0.04 in.) [D].

Page 98

6-6 CAMSHAFT/CRANKSHAFT

Crankcase

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

•

crankcase.

Install the gasket on the crankcase.

•

Install the crankcase cover and tighten the crankcase cover bolts

•

following the tightening sequence shown - F

Torque - Crankcase Cover Bolts: 25 N1m (2.6 kg



Do not turn one screw down completely before the others, as it may

cause the crankcase cover to warp.

H451V, 500V, 531V.

m, 19.0 ft

lb)

Install the crankcase cover and tighten the crankcase cover bolts

•

following the tightening sequence shown - F

Torque - Crankcase Cover Bolts: 25 N



Do not turn one screw down completely before the others, as it may

cause the crankcase cover to warp.

H601V, 641V, 680V.

m (2.6 kg1m, 19.0 ft

lb)

Inspection

Measure the inside diameter [A] of the PTO shaft bearing on the

•

crankcase cover at several points. This bearing is not replaceable.

Replace the crankcase cover if the inside diameter is more than the

service limit.

PTO Shaft Bearing Inside Diameter

Model Service Limit FH451V, 500V, 531V 35.15 mm (1.384 in.) FH601V, 641V, 680V, 721V 40.15 mm (1.581 in.)

Measure the inside diameter [A] of the crankshaft journal bearing

•

on the crankcase at several points. This bearing is not replaceable. Replace the crankcase if the inside diameter is more than the service limit.

Crankshaft Journal Bearing Inside Diameter

Model Service Limit FH451V, 500V, 531V 35.15 mm (1.384 in.) FH601V, 641V, 680V, 721V 40.15 mm (1.581 in.)

Page 99

Crankcase

Cleaning

Remove:

•

Camshaft and Tappets (see Camshaft, Tappet Removal) Crankshaft (see Crankshaft Removal)

Clean up the crankcase and coverwith a high ﬂash-point solvent, and

•

blow out any foreign particles that may be in the pocketsinside of the crankcase with compressed air.

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

CAMSHAFT/CRANKSHAFT 6-7

Page 100

6-8 CAMSHAFT/CRANKSHAFT

Breather

The function of the breather is to create a vacuum in the crankcase which prevents oil from being forced out of the engine through the piston rings, oil seals or gaskets. A sealed-type crankcase emission control system is used to eliminate blow-by gases. The blow-by gases are led to the breather chamber through the crankcase and the camshaft. Then, it is drawn into the clean side of the air cleaner through the cylinder head and the hose and mixed with the clean air ﬂow, and subsequently coming into the combustion chamber through the carburetor and the intake manifold.

Oil is primarily separated from the gases while passing through the inside of the rocker chamber from the crankcase, and secondly separated from the gases in the breather chamber, and then returned back to the crankcase cover.

Kawasaki FH500V User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

General Information

Fuel System

Cooling System

Engine Top End

Lubrication System

Camshaft/Crankshaft