Page 9 of 426

FBU00801
RENSEIGNEMENTS
IMPORTANTS SUR CE MANUEL
LE NON-RESPECT DES AVERTISSEMENTS DON-
NÉS DANS CE MANUEL PEUT ENTRAÎNER DES
BLESSURES GRAVES ET LA MORT.
Les informations particulièrement importantes sont repé-
rées par les notations suivantes:_ Le symbole de danger incite à ÊTRE VIGILANT, CAR
LA SÉCURITÉ EST EN JEU!
AVERTISSEMENT
_ Le non-respect des instructions données sous un
AVERTISSEMENT peut entraîner des blessures gra-ves ou la mort
du pilote, d’un tiers ou d’une personne
inspectant ou réparant le véhicule.
SBU00801
INFORMACIÓN IMPORTANTE
SOBRE ESTE MANUAL
LA INOBSERVANCIA DE LAS ADVERTENCIAS
CONTENIDAS EN ESTE MANUAL PUEDE ACA-
RREAR LESIONES GRAVES O INCLUSO MOR-
TALES.
La información de especial importancia se señala
en este manual con las siguientes notaciones:El símbolo de alerta de seguridad significa ¡ATEN-
CIÓN! ¡MANTÉNGASE ALERTA! ¡PELIGRA SU
SEGURIDAD!
ADVERTENCIA
La inobservancia de las instrucciones de ADVER-
TENCIA puede ser causa de lesiones graves o mor-tales
para el usuario de la máquina, las personas si-
tuadas en sus proximidades o los técnicos
encargados de su inspección o reparación.
U5LP63.book Page 2 Monday, March 10, 2003 2:06 PM
Page 10 of 426
CAUTION:
A CAUTION indicates special precautions that
must be taken to avoid damage to the machine.NOTE:NOTE:A NOTE provides key information to make proce-
dures easier or clearer.
U5LP63.book Page 3 Monday, March 10, 2003 2:06 PM
Page 11 of 426
ATTENTION:_ Un ATTENTION indique les précautions particulières à
prendre pour éviter d’endommager le véhicule.N.B.:N.B.: Un N.B. fournit les renseignements nécessaires à la clari-
fication et à la simplification des divers travaux.
AT E N C I O N :
Los avisos de ATENCION indican precauciones es-
peciales que deben adoptarse para evitar que la má-
quina sufra daños.NOTA:NOTA: Las NOTAS contienen información importante para
facilitar o aclarar los procedimientos.
U5LP63.book Page 4 Monday, March 10, 2003 2:06 PM
Page 12 of 426
EBU00011
2-IMPORTANT NOTICE
This machine is designed and manufactured for
OFF-ROAD use only. It is illegal and unsafe to op-
erate this machine on any public street, road or
highway.
This machine complies with all applicable OFF-
ROAD noise level and spark arrester laws and
regulations in effect at the time of manufacture.
Please check your local riding laws and regula-
tions before operating this machine.
EBU01056
YFM660RS
OWNER’S MANUAL
©2003 by Yamaha Motor Co., Ltd.
1st edition, February 2003
All rights reserved. Any reprinting or
unauthorized use without the written
permission of Yamaha Motor Co., Ltd.
is expressly prohibited.
Printed in Japan.
U5LP63.book Page 1 Monday, March 10, 2003 2:06 PM
Page 13 of 426

FBU00011
AVIS IMPORTANT
Ce véhicule est conçu et fabriqué pour une utilisation
TOUT-TERRAIN uniquement. La conduite de ce véhi-
cule sur la voie publique est illégale et dangereuse.
Ce véhicule est conforme à toutes les législations relati-
ves au déparasitage et au bruit des tout-terrains en vi-
gueur au moment de la fabrication.
Prendre connaissance des règlements locaux avant de
conduire ce véhicule.
FBU01056
YFM660RS
MANUEL DU PROPRIÉTAIRE
©2003 par Yamaha Motor Co., Ltd.
1
re édition, février 2003
Tous droits réservés. Toute réimpression ou
utilisation non autorisée sans la permission
écrite de la Yamaha Motor Co., Ltd.
est formellement interdite.
Imprimé au Japon
SBU00011
AVISO IMPORTANTE
Esta máquina ha sido fabricada y diseñada única-
mente para su utilización FUERA DE CARRETERA.
Por lo tanto, es ilegal y, al mismo tiempo, peligroso,
circular con ella por autopistas, carreteras o cual-
quier otra vía pública.
La máquina satisface todos los requisitos sobre nivel
sonoro y emisión de chispas en circulación FUERA
DE CARRETERA, establecidos por la reglamenta-
ción y las leyes vigentes en el momento de su fabri-
cación.
Se ruega consultar las leyes y reglamentación local
sobre vehículos a motor antes de usar la motocicleta.
SBU01056
YFM660RS
MANUAL DEL PROPIETARIO
©2003 por Yamaha Motor Co., Ltd.
1ª edición, febrero 2003
Reservados todos los derechos. Queda
expresamente prohibida cualquier reimpresión
o uso no autorizado sin el consentimiento por
escrito de Yamaha Motor Co., Ltd.
Impreso en Japón.
U5LP63.book Page 2 Monday, March 10, 2003 2:06 PM
Page 14 of 426

EBU00015
1-CONTENTS
LOCATION OF THE WARNING
AND SPECIFICATION LABELS ............. 1-1
SAFETY INFORMATION ......................... 2-1
DESCRIPTION AND MACHINE
IDENTIFICATION ................................... 3-1
Identification number records .............. 3-3
Key identification number .................... 3-5
Vehicle identification number .............. 3-5
Model label ........................................... 3-7
CONTROL FUNCTIONS ........................ 4-1
Main switch........................................... 4-1
Indicator and warning lights ................. 4-3
Handlebar switches ........................... 4-11
Throttle lever ..................................... 4-15
Speed limiter ...................................... 4-17
Clutch lever ....................................... 4-19
Brake lever ......................................... 4-19
Brake pedal ........................................ 4-21
Parking brake .................................... 4-23
Shift pedal ......................................... 4-27
Reverse knob .................................... 4-27
1234
Fuel tank cap .................................... 4-29
Fuel cock ........................................... 4-29
Starter (choke) .................................. 4-31
Seat.................................................... 4-33
Front shock absorber adjustment ...... 4-35
Rear shock absorber adjustment ....... 4-37
PRE-OPERATION CHECKS .................. 5-1
Front and rear brakes .......................... 5-5
Fuel ...................................................... 5-9
Engine oil ........................................... 5-13
Coolant............................................... 5-17
Chain ................................................. 5-19
Throttle lever ...................................... 5-21
Fittings and fasteners......................... 5-21
Lights ................................................. 5-21
Switches............................................. 5-21
Tires .................................................. 5-23
How to measure tire pressure ........... 5-27
Tire wear limit .................................... 5-29
5
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Page 15 of 426

OPERATION ...........................................6-1
Starting a cold engine ..........................6-3
Starting a warm engine ........................6-9
Warming up ..........................................6-9
Reverse knob operation and
reverse driving ..................................6-11
Shifting ................................................6-15
To start out and accelerate .................6-17
To decelerate ......................................6-21
Engine break-in ..................................6-23
Parking ...............................................6-27
Parking on a slope ..............................6-29
Accessories and loading ....................6-31
RIDING YOUR ATV..................................7-1
Getting to know your ATV .....................7-3
Ride with care and good judgement .....7-5
Be careful where you ride ...................7-27
Turning your ATV ................................7-39
Climbing uphill.....................................7-45
Riding downhill ....................................7-55
Crossing a slope .................................7-59
Crossing through shallow water ..........7-63
Riding over rough terrain ....................7-67
Sliding and skidding ............................7-69
What to do if .......................................7-73
What to do...........................................7-73
67
PERIODIC MAINTENANCE AND
ADJUSTMENT ........................................ 8-1
Owner’s manual and tool kit ................. 8-3
Periodic maintenance/lubrication ......... 8-7
Panel removal and installation ........... 8-15
Engine oil and oil filter cartridge ......... 8-17
Cooling system ................................... 8-33
Changing the coolant.......................... 8-37
Spark plug inspection ......................... 8-45
Air filter element cleaning ................... 8-49
Carburetor adjustment ....................... 8-55
Idle speed adjustment ........................ 8-57
Throttle lever adjustment ................... 8-59
Valve clearance adjustment .............. 8-61
Front and rear brake pad inspection... 8-63
Brake fluid level inspection ................. 8-65
Brake fluid replacement ...................... 8-69
Front brake lever free play.................. 8-71
Brake pedal height adjustment ........... 8-73
Parking brake adjustment ................... 8-75
Adjusting the rear brake light switch ... 8-79
Clutch lever free play adjustment ...... 8-81
Drive chain slack check ...................... 8-83
Drive chain slack adjustment .............. 8-85
Lubricating the drive chain ................. 8-87
Cable inspection and lubrication ........ 8-91
8
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Page 16 of 426

Brake and shift pedal/brake and
clutch lever lubrication ..................... 8-91
Front upper and lower arm pivot
lubrication ......................................... 8-93
Rear arm pivot lubrication .................. 8-95
Wheel removal ................................... 8-99
Wheel installation ............................ 8-101
Battery ............................................. 8-103
Battery maintenance ....................... 8-107
Fuse replacement ............................ 8-109
Replacing a headlight bulb ............... 8-111
Tail/brake light bulb replacement ..... 8-121
Troubleshooting ............................... 8-123
Troubleshooting chart ...................... 8-125
CLEANING AND STORAGE .................. 9-1
A. Cleaning .......................................... 9-1
B. Storage ........................................... 9-7
SPECIFICATIONS ................................ 10-1
CONVERSION TABLE .......................... 11-1
91011U5LP63.book Page 3 Monday, March 10, 2003 2:06 PM