2008 YAMAHA YFZ450 maintenance

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INTRODUCTION
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Congratulations on your purchase of the Yamaha YFZ450X/YFZ450SPX. This ATV represents the result
of many years of Yamaha experience in the production of fine sporting, touring, and pacesetting racing ma-
chines. 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 understanding of the features and operation of this ATV.
This manual includes important safety information. It provides information about special tech-
niques and skills necessary to ride the ATV.
It also includes basic maintenance and inspection proce-
dures. If you have any questions regarding the operation or maintenance of your ATV, please consult a
Yamaha dealer.
AN IMPORTANT SAFETY MESSAGE:


READ THIS MANUAL COMPLETELY BEFORE OPERATING YOUR ATV. MAKE SURE YOU UNDER-
STAND ALL INSTRUCTIONS.

PAY CLOSE ATTENTION TO THE WARNING AND CAUTION LABELS ON THE ATV.

THIS ATV, AND ANY OTHER ATV OVER 90 cc, SHOULD NOT BE RIDDEN BY ANYONE UNDER 16
YEARS OF AGE.

THIS ATV IS A HIGH-PERFORMANCE ATV FOR OFF-ROAD USE ONLY, FOR SPORT-TYPE REC-
REATIONAL AND COMPETITIVE USE BY EXPERIENCED OPERATORS.

Parking ...................................................... 6-5
Parking on a slope .................................... 6-6
Accessories and loading ........................... 6-6
RIDING YOUR ATV ...................................... 7-1
GETTING TO KNOW YOUR ATV.............. 7-2
RIDE WITH CARE AND GOOD
JUDGEMENT ........................................... 7-2
BE CAREFUL WHERE YOU RIDE ............ 7-8
TURNING YOUR ATV ............................. 7-12
CLIMBING UPHILL .................................. 7-14
RIDING DOWNHILL................................. 7-16
CROSSING A SLOPE.............................. 7-17
CROSSING THROUGH SHALLOW
WATER .................................................. 7-18
RIDING OVER ROUGH TERRAIN .......... 7-20
SLIDING AND SKIDDING ........................ 7-20
WHAT TO DO IF... ................................... 7-21
WHAT TO DO... ....................................... 7-21
PERIODIC MAINTENANCE AND MINOR
REPAIR .......................................................... 8-1
Owner’s manual and tool kit ...................... 8-1
Periodic maintenance chart for the
emission control system .......................... 8-3
General maintenance and lubrication
chart ........................................................ 8-5
Removing and installing the panel ............ 8-9
Checking the spark plug .......................... 8-10Engine oil and oil filter element ................ 8-14
Coolant .................................................... 8-20
Cleaning the air filter element .................. 8-24
Cleaning the spark arrester ..................... 8-28
Adjusting the carburetor ........................... 8-29
Checking the engine idling speed ............ 8-30
Adjusting the throttle cable free play ........ 8-30
Valve clearance ....................................... 8-31
Checking the front and rear brake pads .. 8-31
Checking the brake fluid level .................. 8-32
Changing the brake fluid .......................... 8-35
Checking the front brake lever free
play ........................................................ 8-36
Checking the brake pedal position ........... 8-36
Adjusting the parking brake free play ...... 8-37
Brake light switches ................................. 8-39
Adjusting the clutch lever free play .......... 8-39
Lubricating the drive chain ....................... 8-41
Checking and lubricating the cables ........ 8-41
Checking and lubricating the brake and
clutch levers ........................................... 8-42
Checking and lubricating the brake and
shift pedals............................................. 8-43
Checking the wheel hub bearings ............ 8-43
Lubricating the swingarm pivots .............. 8-43
Lubricating the upper and lower arm
pivots ..................................................... 8-44
Battery ..................................................... 8-45
Replacing the fuse ................................... 8-46

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that is proper for the terrain, visibility, operating
conditions, 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. Al-
ways 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 op-
eration.

Always go slowly and be extra careful when op-
erating on unfamiliar terrain. Always be alert to
changing terrain conditions when operating the
ATV.

Never operate on excessively rough, slippery or
loose terrain until you have learned and prac-
ticed the skills necessary to control the ATV on
such terrain. Always be especially cautious on
these kinds of terrain.

Always follow proper procedures for turning as
described in this manual. Practice turning at low
speeds before attempting to turn at faster
speeds and never turn at excessive speeds.

Never operate the ATV on hills too steep for the
ATV or for your abilities. Practice on smaller hillsbefore attempting larger hills.

Always follow proper procedures for climbing
hills as described in this manual. Check the ter-
rain carefully before you start up any hill. Never
climb hills with excessively slippery or loose sur-
faces. Shift your weight forward. Never open the
throttle suddenly or make sudden gear changes.
Never go over the top of a hill at high speed.

Always follow proper procedures for going down
hills and for braking on hills as described in this
manual. Check the terrain carefully before you
start down any hill. Shift your weight backward.
Never go down a hill at high speed. Avoid going
down a hill at an angle that would cause the ve-
hicle to lean sharply to one side. Go straight
down the hill where possible.

Always follow proper procedures for crossing
the side of a hill as described in this manual.
Avoid hills with excessively slippery or loose sur-
faces. Shift your weight to the uphill side of the
ATV. Never attempt to turn the ATV around on
any hill until you have mastered the turning tech-
nique described in this manual on level ground.
Avoid crossing the side of a steep hill if possible.

Always use proper procedures if you stall or roll
backwards when climbing a hill. To avoid stall-

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PRE-OPERATION CHECKS
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Pre-operation check list
Before operating this ATV, be sure to check the items listed in the following table.
NOTE:

The maintenance of some items in the table has to be performed by a Yamaha dealer. Refer to the “Periodic
maintenance and lubrication chart” on page 8-3 to determine which service should be performed by a
Yamaha dealer.
ITEM ROUTINE PAGE
Fuel


Check fuel level in fuel tank, and add recommended fuel if neces-
sary.

Check fuel line for leakage. Correct if necessary.4-8, 5-4
Engine oil

Check oil level in engine, and add recommended oil to specified
level if necessary.

Check ATV for oil leakage. Correct if necessary.5-4, 8-14
Coolant

Check coolant level in reservoir, and add recommended coolant to
specified level if necessary.

Check cooling system for leakage. Correct if necessary.5-4, 8-20
Front brake

Check operation. If soft or spongy, have Yamaha dealer bleed
hydraulic system.

Check brake pads for wear, and replace if necessary.

Check brake fluid level in reservoir, and add recommended brake
fluid to specified level if necessary.

Check hydraulic system for leakage. Correct if necessary.5-4, 8-31, 8-32, 8-36

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WARNING

EWB00480
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 the Owner’s
Manual. Failure to inspect increases the possibility of an accident or equipment damage.

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PERIODIC MAINTENANCE AND MINOR REPAIR
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Safety is an obligation of the owner. Periodic in-
spection, adjustment and lubrication will keep your
ATV in the safest and best operating condition
possible. The most important points of inspection,
adjustment, and lubrication are explained on the
following pages.
The intervals given in the periodic maintenance
and lubrication chart should be considered as a
general guide under normal riding conditions.
However, DEPENDING ON THE WEATHER,
TERRAIN, GEOGRAPHICAL LOCATION, AND
INDIVIDUAL USE, THE MAINTENANCE INTER-
VALS MAY NEED TO BE SHORTENED.
WARNING

EWB01840
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 start fires. Turn off the en-
gine when performing maintenance unless
otherwise specified. Have a Yamaha dealer
perform the service if you are not familiar with
maintenance work.
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Owner’s manual and tool kit
Be sure to put this owner’s manual in the plastic
bag and to always carry it as well as the owner’s
tool kit and the low-pressure tire gauge in their re-
spective compartments under the seat.
1. Low-pressure tire gauge
2. Owner’s tool kit
3. Owner’s manual
3 21

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The service information included in this manual
and the tools provided in the owner’s tool kit are in-
tended to assist you in the performance of preven-
tive maintenance and minor repairs. However,
additional tools such as a torque wrench may be
necessary to perform certain maintenance work
correctly.
NOTE:

If you do not have the tools or experience required
for a particular job, have a Yamaha dealer perform
it for you.
WARNING

EWB01850
Never modify this ATV through improper in-
stallation or use of accessories, as it may
cause changes in handling, which in some sit-
uations could lead to an accident. All parts and
accessories added to this ATV should be gen-
uine Yamaha or equivalent components de-
signed for use on this ATV and should be
installed and used according to instructions. If
you have questions, consult an authorized
Yamaha ATV dealer.

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EBU21742
Periodic maintenance chart for the emission control system
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 inter-
vals. However, keep in mind that if the ATV isn’t used for a long period of time, the month maintenance
intervals should be followed.

Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools,
data and technical skills.
NO. ITEMCHECK OR MAINTENANCE
JOBINITIAL EVERY
Whichev-
er comes
firstmonth 1 3 6 6 12
km
(mi)320
(200)1300
(800)2500
(1600)2500
(1600)5000
(3200)
hours 20 80 160 160 3201
*
Fuel line


Check fuel hoses for cracks or other damage, and
replace if necessary.
√√√
2 Spark plug

Check condition and clean, regap, or replace if
necessary.
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3
*
Valves


Check valve clearance and adjust if necessary.
√ √√√
4
*
Carburetor


Check starter (choke) operation and correct if nec-
essary.

Check engine idling speed and adjust if neces-
sary.
√√√√
5
*
Crankcase breather
system


Check breather hose for cracks or other damage,
and replace if necessary.
√√√