YFM660FS

5KM2-AE3

SUPPLEMENTARY

SERVICE MANUAL

FOREWORD

This Supplementary Service Manual has been prepared to introduce new service and data for the

YFM660FS. For complete service information procedures it is necessary to use this Supplementary

Service Manual together with the following manual.

YFM660F(P) 2002 SERVICE MANUAL: 5KM2-AE1

YFM660FR SUPPLEMENTARY SERVICE MANUAL: 5KM2-AE2

YFM660FS

SUPPLEMENTARY

SERVICE MANUAL

©2003 by Yamaha Motor Co., Ltd.

First edition, April 2003

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-based 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

CONTENTS

GENERAL INFORMATION ..............................................................................1

FEATURES ...............................................................................................1

OVERRIDE SWITCH (DEACTIVATING THE SPEED LIMITER

WHEN THE DIFFERENTIAL IS LOCKED) ...........................................1

SPECIFICATIONS ............................................................................................3

GENERAL SPECIFICATIONS ..................................................................3

MAINTENANCE SPECIFICATIONS .........................................................4

ENGINE ................................................................................................4

CHASSIS ..............................................................................................5

ELECTRICAL ........................................................................................5

CHASSIS ..........................................................................................................6

STEERING SYSTEM ................................................................................6

INSTALLING THE REAR BRAKE LEVER ............................................6

ELECTRICAL ...................................................................................................7

CHECKING THE SWITCH ........................................................................7

CHECKING THE SWITCH CONTINUITY .............................................7

SIGNAL SYSTEM .....................................................................................9

CIRCUIT DIAGRAM ..............................................................................9

YFM660FS WIRING DIAGRAM

GEN

INFO

– 1 –

GENERAL INFORMATION

FEATURES

OVERRIDE SWITCH

(DEACTIVATING THE SPEED LIMITER WHEN THE DIFFERENTIAL IS LOCKED)

This model is equipped with a speed limiter system (35 km/h [22 mph]) that operates when the dif-

ferential is locked and the ATV is traveling forward. If additional engine power is required (e.g., to

free the ATV from mud) when the ATV is traveling forward and the differential is locked, the speed

limiter can be temporarily deactivated by pressing the override switch.

NOTE:

The speed limiter is deactivated only while the override switch is being pressed.

1 Override switch

When the override switch is pressed, the segments of the speedometer digits are displayed as fol-

lows.

NOTE:

G When the front differential gear is locked and the drive select lever is in the “L”, “H”, “N”, or “P”

position, the display changes when the override switch is pressed. (The speedometer display is

not displayed at this time.)

G When the front differential gear is not locked or the drive select lever is in the “R” position, the dis-

play does not change even if the override switch is pressed.

km/h

ODOTRIP AB

CLOCKHOUR

E

F

F

F

OFF

LOCK

0.2s

0.2s

0.2s

0.2s

0.2s

0.2s

FEATURES

GEN

INFO

– 2 –

FEATURES

CAUTION:

If the segments of the speedometer digits show the override display when the override

switch is not pressed, the speed limiter system is malfunctioning. Check the override switch

and ignition system, and then repair if necessary.

– 3 –

SPEC

SPECIFICATIONS

GENERAL SPECIFICATIONS

Item

Standard

Model code:

5KMJ/5KMR (for CDN)

5KMK/5KMS (for Europe)

5KML (for Oceania)

Transmission:

Primary reduction system

V-belt

Secondary reduction system

Shaft drive

Secondary reduction ratio

41/21 × 24/18 × 33/9 (9.544)

Transmission type

V-belt automatic

Operation

Left hand operation

Single speed automatic

2.45 ~ 0.70 : 1

Sub transmission ratio

low

35/17 (2.058)

high

26/21 (1.238)

Reverse gear

25/17 (1.471)

GENERAL SPECIFICATIONS

– 4 –

SPEC

MAINTENANCE SPECIFICATIONS

ENGINE

Item

Standard

Limit

Carburetor:

I. D. mark

5KMA 10

----

Main jet

(M.J)

#153.8

----

Main air jet

(M.A.J)

#70

----

Jet needle

(J.N)

6JPH9-53-2

----

Needle jet

(N.J)

O-0M

----

Pilot air jet

(P.A.J.1)

#60

----

Pilot air jet

(P.A.J.2)

1.5

----

Pilot outlet

(P.O)

1.1

----

Pilot jet

(P.J)

#40

----

Pilot screw

(P.S)

3 turns out

----

Bypass 1

(B.P.1)

0.8

----

Bypass 2

(B.P.2)

0.8

----

Bypass 3

(B.P.3)

0.8

----

Valve seat size

(V.S)

3.0

----

Starter jet

(G.S.1)

#55

----

Starter jet

(G.S.2)

0.8

----

Throttle valve size

(Th.V)

#105

----

Float height

(F.H)

13 mm (0.51 in)

----

Fuel level

(F.L)

4.5 mm (0.18 in)

----

Engine idle speed

1,450 ~ 1,550 r/min

----

Intake vacuum

30.7 ~ 33.3 kPa

(230 ~ 250 mmHg, 9.07 ~ 9.83 inHg)

----

MAINTENANCE SPECIFICATIONS

– 5 –

SPEC

CHASSIS

ELECTRICAL

Item

Standard

Limit

Front suspension:

Shock absorber travel

86 mm (3.39 in)

----

Fork spring free length

296.5 mm (11.67 in) (for CDN)

290.6 mm

(11.44 in)

307.0 mm (12.09 in) (for Europe

and Oceania)

300.9 mm

(11.85 in)

Spring fitting length

237 mm (9.33 in)

----

Spring rate

(K1)

20 N/mm

(2.04 kg/mm, 114.2 lb/in)

----

Stroke

(K1)

0 ~ 86 mm (0 ~ 3.39 in)

----

Optional spring

No

----

Rear suspension:

Shock absorber travel

95 mm (3.74 in)

----

Spring free length

278.5 mm (10.96 in) (for CDN)

----

285.5 mm (11.24 in) (for Europe

and Oceania)

----

Spring fitting length

237 mm (9.33 in)

----

Spring rate

(K1)

36.4 N/mm

(3.71 kg/mm, 207.84 lb/in)

----

Stroke

(K1)

0 ~ 95 mm (0 ~ 3.74 in)

----

Optional spring

No

----

Item

Standard

Limit

C.D.I.:

Magneto model/manufacturer

F4T469/MITSUBISHI

----

Pickup coil resistance/color

459 ~ 561 Ω at 20 °C (68 °F)/

White/Red – White/Green

----

Rotor rotation direction sensing coil resis-

tance/color

0.063 ~ 0.077 Ω at 20 °C (68 °F)/

Red – White/Blue

----

C.D.I. unit model/manufacturer

F8T40372/MITSUBISHI

----

Charging system:

Type

A.C. magneto generator

----

Model/manufacturer

F4T469/MITSUBISHI

----

Nominal output

14 V 21 A at 5,000 r/min

----

Charging coil resistance/color

0.32 ~ 0.43 Ω at 20 °C (68 °F)/

White – White

----

MAINTENANCE SPECIFICATIONS

– 6 –

CHAS

STEERING SYSTEM

CHASSIS

STEERING SYSTEM

INSTALLING THE REAR BRAKE LEVER

1.Install:

G Handlebar switch 1

G Rear brake lever

G Lever bracket 2

NOTE:

Install the lever bracket as shown.

a 74.5 mm (2.9 in)

– 7 –

–

+

ELEC

CHECKING THE SWITCH

ELECTRICAL

CHECKING THE SWITCH

CHECKING THE SWITCH CONTINUITY

Refer to “CHECKING THE SWITCH” in CHAPTER 9 (Manual No.: 5KM2-AE1) and check for conti-

nuity between lead terminals.

Poor connection, no continuity → Correct or replace.

* ^{The coupler locations are circled.}

L

B

Y

G

Br

L/B

1

5

6

C

7

2

3

PUSH

Br L Y G

B

R/W

L/B L/G

Br/L Br

R

L/R Sb Br Gy G/R B

R/B

L/B

2WD

4WD

LOCK

L/G

L/B

L/R

Sb

Gy

Br

G/R

B

(BLACK)

(GRAY)

P

L

Gy

W

ON

OFF

R

Br

Br/L

Br

B

OFF

ON

P

P Br

Br

Y

(BLACK)

8

B

B

(BLACK)

9

0

A

B

B

B

4

PUSH

B

Lg

R/B R/W

Lg