Page 4 of 452
EBU12031
1-INTRODUCTION
Congratulations on your purchase of the Yamaha
YFZ450. It represents the result of many years of
Yamaha experience in the production of fine sport-
ing, touring, and pacesetting racing machines.
With the purchase of this Yamaha, you can now
appreciate the high degree of craftsmanship and
reliability that have made Yamaha a leader in
these fields.
This manual will provide you with a good basic un-
derstanding of the features and operation of this
ATV.
This manual includes important safety in-
formation. It provides information about spe-
cial techniques and skills necessary to ride
your ATV. It also includes basic maintenance and
inspection procedures. If you have any questions
regarding the operation or maintenance of your
ATV, please consult a Yamaha dealer.
U5TG61.book Page 2 Friday, April 2, 2004 11:28 AM
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OPERATION ............................................6-1
Starting a cold engine ...........................6-3
Starting a warm engine .........................6-9
Warming up...........................................6-9
Shifting ................................................6-11
To start out and accelerate .................6-13
To decelerate ......................................6-17
Engine break-in ...................................6-19
Parking ................................................6-23
Parking on a slope ..............................6-25
Accessories and loading .....................6-29
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 ................................7-41
Climbing uphill.....................................7-47
Riding downhill ....................................7-57
Crossing a slope .................................7-61
Crossing through shallow water ..........7-65
Riding over rough terrain ....................7-69
Sliding and skidding ............................7-71
What to do if ........................................7-75
What to do...........................................7-75
67
PERIODIC MAINTENANCE AND
ADJUSTMENT ......................................... 8-1
Owner’s manual and tool kit ................. 8-3
Periodic maintenance/lubrication.......... 8-7
Panel removal and installation............ 8-17
Engine oil and oil filter element........... 8-23
Cooling system ................................... 8-41
Changing the coolant.......................... 8-45
Spark plug inspection ......................... 8-53
Air filter element cleaning ................... 8-65
Carburetor adjustment ........................ 8-73
Idle speed adjustment ........................ 8-75
Valve clearance adjustment ............... 8-75
Throttle lever adjustment .................... 8-77
Front brake pad inspection ................. 8-79
Rear brake pad inspection.................. 8-81
Brake fluid level inspection ................. 8-83
Brake fluid replacement ...................... 8-87
Front brake lever free play.................. 8-89
Brake pedal height adjustment ........... 8-91
Parking brake adjustment ................... 8-93
Adjusting the rear brake light switch ... 8-97
Clutch lever free play adjustment ....... 8-99
Drive chain slack check .................... 8-101
Drive chain slack adjustment ............ 8-103
Lubricating the drive chain................ 8-107
Cable inspection and lubrication....... 8-111
8
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Brake pedal, brake lever and
clutch lever lubrication.................... 8-113
Front upper and lower arm pivot
lubrication ....................................... 8-117
Rear arm pivot lubrication ................ 8-119
Wheel removal ................................. 8-121
Wheel installation ............................. 8-123
Battery .............................................. 8-125
Battery maintenance ........................ 8-129
Fuse replacement............................. 8-131
Replacing a headlight bulb ............... 8-133
Headlight beam adjustment.............. 8-139
Tail/brake light bulb replacement ..... 8-141
Troubleshooting................................ 8-143
Troubleshooting chart....................... 8-147
CLEANING AND STORAGE ................... 9-1
A. Cleaning ........................................... 9-1
B. Storage ............................................ 9-7
SPECIFICATIONS ................................ 10-1
CONVERSION TABLE .......................... 11-1
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2-5
Never operate at speeds too fast for your skills
or the conditions. Always go at a speed that is
proper for the terrain, visibility, operating condi-
tions, and your experience.
Never attempt wheelies, jumps, or other stunts.
Always inspect your ATV each time you use it
to make sure it is in safe operating condition.
Always follow the inspection and maintenance
procedures and schedules described in this
manual.
Always keep both hands on the handlebars
and both feet on the footrests of the ATV during
operation.
Always go slowly and be extra careful when op-
erating on unfamiliar terrain. Always be alert to
changing terrain conditions when operating the
ATV.
U5TG61.book Page 5 Friday, April 2, 2004 11:28 AM
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5-4
WARNING
_ Always inspect your ATV each time you use it to make sure the ATV is in safe operating condition.
Always follow the inspection and maintenance procedures and schedules described in the Own-
er’s Manual. Failure to inspect increases the possibility of an accident or equipment damage. _
AVERTISSEMENT
_ Toujours effectuer ces contrôles avant chaque départ afin de s’assurer que le VTT peut être utilisé en toute sécu-
rité. Toujours respecter les procédés et intervalles de contrôle et d’entretien repris dans ce manuel. Omettre ces
contrôles accroît les risques d’accident ou d’endommagement du véhicule. _
ADVERTENCIA
_ Inspeccionar siempre el ATV cada vez que vaya a utilizarse, para asegurarse de que está en condicio-
nes de funcionar sin peligro. Seguir siempre los procedimientos y programas de inspección y mante-
nimiento descritos en el Manual del Propietario. Si no se inspecciona la máquina, aumenta el riesgo de
accidente o avería. _ U5TG61.book Page 4 Friday, April 2, 2004 11:28 AM
Page 268 of 452
8-1
EBU05160
1-PERIODIC MAINTENANCE AND
ADJUSTMENTPeriodic inspection, adjustment and lubrication will
keep your machine in the safest and most efficient
condition possible. Safety is an obligation of the
machine owner. The most important points of ma-
chine inspection, adjustment and lubrication are
explained on the following pages.
WARNING
_ Never service an engine while it is running.
Moving parts can catch clothing or parts of the
body, causing injury. Electrical components
can cause shocks or can start fires. Turn off
the engine when performing maintenance un-
less otherwise specified. Have a Yamaha deal-
er perform service if you are not familiar with
machine service. _
U5TG61.book Page 1 Friday, April 2, 2004 11:28 AM
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8-3 1. Owner’s manual 2. Owner’s tool kit
3. Low-pressure tire gauge
1. Manuel du propriétaire 2. Trousse à outils
3. Manomètre basse pression pour pneus
1. Manual del propietario 2. Equipo de herramientas
3. Comprobador de la presión de los neumáticos
EBU12220
Owner’s manual and tool kit
You are recommended to put this owner’s manual
and low-pressure tire gauge in the vinyl bag and
always carry them along with the owner’s tool kit
under the seat. The service information included in
this manual is intended to provide you, the owner,
with the necessary information for completing your
own preventive maintenance and minor repairs.
The tools provided in the owner’s tool kit are suffi-
cient for this purpose, except that a torque wrench
is also necessary to properly tighten nuts and
bolts.NOTE:_ If you do not have a torque wrench available dur-
ing a service operation requiring one, take your
machine to a Yamaha dealer to check the torque
settings and adjust them as necessary.
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8-7
EBU02621
PERIODIC MAINTENANCE/LUBRICATION
NOTE:_
For ATVs not equipped with an odometer or an hour meter, follow the month maintenance intervals.
For ATVs equipped with an odometer or an hour meter, follow the km (mi) or hours maintenance in-
tervals. However, keep in mind that if the ATV isn’t used for a long period of time, the month mainte-
nance intervals should be followed.
_
ITEM ROUTINEWhichever
comes firstINITIAL EVERY
month136612
km
(mi)320
(200)1,200
(750)2,400
(1,500)2,400
(1,500)4,800
(3,000)
hours 20 75 150 150 300
Valves*Check valve clearance.
Adjust if necessary.
Cooling systemCheck for coolant leakage.
Repair if necessary.
Replace coolant every 24 months.Spark plugCheck condition.
Adjust gap and clean.
Replace if necessary.Air filter elementClean.
Replace if necessary.Every 20–40 hours
(More often in wet or dusty areas.)
Carburetor*Check starter (choke) operation.
Adjust engine idling speed.Crankcase breather
system*Check breather hose for cracks or damage.
Replace if necessary.Exhaust system*Check for leakage.
Tighten if necessary.
Replace gasket if necessary.Fuel line*Check fuel hose for cracks or damage.
Replace if necessary.Engine oil
Replace (Warm engine before draining).U5TG61.book Page 7 Friday, April 2, 2004 11:28 AM