YFM660F(P)

5KM2-AE1

SERVICEMANUAL

2002

YFM660F(P) 2002

SERVICE MANUAL

© 2001 by Yamaha Motor Co., Ltd.

First edition, May 2001

All rights reserved.

Any reproduction or unauthorized use

without the written permission of

Yamaha Motor Co., Ltd.

is expressly prohibited.

EB001000

NOTICE

This manual was produced by the Yamaha Motor Company primarily for use by Yamaha dealers

and their qualified mechanics. It is not possible to include all the knowledge of a mechanic in one

manual, so it is assumed that anyone who uses this book to perform maintenance and repairs on

Yamaha machine has a basic understanding of the mechanical ideas and the procedures of

machine repair. Repairs attempted by anyone without this knowledge are likely to render the

machine unsafe and unfit for use.

Yamaha Motor Company, Ltd. is continually striving to improve all its models. Modifications and sig-

nificant changes in specifications or procedures will be forwarded to all authorized Yamaha dealers

and will appear in future editions of this manual where applicable.

NOTE:

Designs and specifications are subject to change without notice.

IMPORTANT INFORMATION

Particularly important information is distinguished in this manual by the following notations.

The Safety Alert Symbol means ATTENTION! BECOME ALERT! YOUR

SAFETY IS INVOLVED!

Failure to follow WARNING instructions could result in severe injury or death

to the machine operator, a bystander or a person inspecting or repairing the

machine.

A CAUTION indicates special precautions that must be taken to avoid dam-

age to the machine.

A NOTE provides key information to make procedures easier or clearer.

WARNING

CAUTION:

NOTE:

EB002000

HOW TO USE THIS MANUAL

MANUAL ORGANIZATION

This manual consists of chapters for the main categories of subjects. (See “Illustrated symbols”)

1st title 1: This is the title of the chapter with its symbol in the upper right corner of each page.

2nd title 2: This title indicates the section of the chapter and only appears on the first page of each

section. It is located in the upper left corner of the page.

3rd title 3: This title indicates a sub-section that is followed by step-by-step procedures accompa-

nied by corresponding illustrations.

EXPLODED DIAGRAMS

To help identify parts and clarify procedure steps, there are exploded diagrams at the start of each

removal and disassembly section.

1. An easy-to-see exploded diagram 4 is provided for removal and disassembly jobs.

2. Numbers 5 are given in the order of the jobs in the exploded diagram. A number that is enclosed

by a circle indicates a disassembly step.

3. An explanation of jobs and notes is presented in an easy-to-read way by the use of symbol marks

6. The meanings of the symbol marks are given on the next page.

4. A job instruction chart 7 accompanies the exploded diagram, providing the order of jobs, names

of parts, notes in jobs, etc.

5. For jobs requiring more information, the step-by-step format supplements 8 are given in addition

to the exploded diagram and the job instruction chart.

EB003000

ILLUSTRATED SYMBOLS

Illustrated symbols 1 to 0 are printed on the

top right of each page and indicate the subject

of each chapter.

1 General information

2 Specifications

3 Periodic checks and adjustments

4 Engine

5 Cooling system

6 Carburetion

7 Drive train

8 Chassis

9 Electrical

0 Troubleshooting

Illustrated symbols A to H are used to identify

the specifications appearing in the text.

A Can be serviced with engine mounted

B Filling fluid

C Lubricant

D Special tool

E Torque

F Wear limit, clearance

G Engine speed

H Ω, V, A

Illustrated symbols I to N in the exploded

diagrams indicate the types of lubricants and

lubrication points.

I Apply engine oil

J Apply gear oil

K Apply molybdenum disulfide oil

L Apply wheel bearing grease

M Apply lightweight lithium-soap base grease

N Apply molybdenum disulfide grease

Illustrated symbols O to P in the exploded

diagrams indicate where to apply a locking

agent O and when to install a new part P.

O Apply the locking agent (LOCTITE^)

P Replace

1

2

3

4

5

6

7

8

9

0

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

GEN

INFO

SPEC

CHK

ADJ

ENG

COOL

CARB

DRIV

CHAS

–

+

ELEC

TRBL

SHTG

T R

.

.

E

G

M

B

LS

M

LT

New

TABLE OF CONTENTS

GENERAL INFORMATION

GEN

INFO 1

SPECIFICATIONS

SPEC 2

PERIODIC CHECKS AND

ADJUSTMENTS

CHK

ADJ 3

ENGINE

ENG 4

COOLING SYSTEM

COOL 5

CARBURETION

CARB 6

DRIVE TRAIN

DRIV 7

CHASSIS

CHAS 8

ELECTRICAL

ELEC 9

TROUBLESHOOTING

TRBL

SHTG 10

–

+

GEN

INFO 1

GEN

INFO

CHAPTER 1.

GENERAL INFORMATION

MACHINE IDENTIFICATION ........................................................................ 1-1

VEHICLE IDENTIFICATION NUMBER ................................................. 1-1

MODEL LABEL ..................................................................................... 1-1

FEATURES ................................................................................................... 1-2

FRONT DIFFERENTIAL ....................................................................... 1-2

TRANSMISSION ................................................................................... 1-9

IMPORTANT INFORMATION .................................................................... 1-10

PREPARATION FOR REMOVAL PROCEDURES ............................. 1-10

REPLACEMENT PARTS .................................................................... 1-10

GASKETS, OIL SEALS AND O-RINGS .............................................. 1-10

LOCK WASHERS/PLATES AND COTTER PINS ............................... 1-11

BEARINGS AND OIL SEALS .............................................................. 1-11

CIRCLIPS ............................................................................................ 1-11

CHECKING OF CONNECTIONS ............................................................... 1-12

SPECIAL TOOLS ....................................................................................... 1-13

GEN

INFO

1 - 1

GEN

INFO

MACHINE IDENTIFICATION

GENERAL INFORMATION

MACHINE IDENTIFICATION

VEHICLE IDENTIFICATION NUMBER

The vehicle identification number 1 is

stamped into the left side of the frame.

MODEL LABEL

The model label 1 is affixed to the frame. This

information will be needed to order spare

parts.

GEN

INFO

1 - 2

FEATURES

FRONT DIFFERENTIAL

1 Adapter

2 Drive clutch

3 Differential side gear (left)

4 Differential pinion gear

5 Ring gear

6 Differential side gear (right)

7 Drive pinion gear

8 Gear motor

È To front wheel

É From the middle gear

FEATURES

GEN

INFO

1 - 3

FEATURES

2WD

Power is transmitted as follows: middle gear → front drive shaft → drive pinion gear 7 → ring gear

5 → differential pinion gear 4. In the 2WD mode, the left differential side gear 3 and the drive

clutch 2 are not engaged, therefore, the left side gear runs idle and does not transmit power to the

left front constant velocity joint.

GEN

INFO

1 - 4

FEATURES

4WD

When the 4WD mode is selected, the gear motor is operated, and the drive clutch 2 moves to the

right and engages with the left differential side gear 3. Accordingly, power is transmitted as follows:

ring gear 5 → differential pinion gear 4 → left differential side gear 3 → drive clutch 2 → adapter

1 → left front constant velocity joint.

Meanwhile, power from the differential pinion gear 4 is transmitted to the right front constant veloc-

ity joint via the right differential side gear 6.

The ring gear 5 and the drive clutch 2 are not engaged at this time. Therefore, the rotational differ-

ence that occurs between the right and left wheels, while the handlebar is being turned, is absorbed

by the difference in the rotational speeds of the ring gear 5 and the left differential side gear 3.