2008 YAMAHA YFZ450 clutch

EBU17420
TABLE OF CONTENTS
SAFETY INFORMATION .............................. 1-1
LOCATION OF THE WARNING AND
SPECIFICATION LABELS ............................ 2-1
DESCRIPTION .............................................. 3-1
Left view ..................................................... 3-1
Right view................................................... 3-1
Controls and instruments ........................... 3-2
INSTRUMENT AND CONTROL
FUNCTIONS .................................................. 4-1
Main switch ............................................... 4-1
Indicator light and warning light ................. 4-1
Handlebar switches ................................... 4-2
Throttle lever ............................................. 4-3
Speed limiter ............................................. 4-4
Clutch lever ............................................... 4-5
Brake lever ................................................ 4-5
Brake pedal ............................................... 4-5
Parking brake lever ................................... 4-6
Shift pedal ................................................. 4-7
Fuel tank cap ............................................. 4-7
Fuel ........................................................... 4-8
Fuel cock ................................................... 4-9Starter (choke) “ ” .................................. 4-10
Seat ......................................................... 4-11
Adjusting the front shock absorber
assemblies ............................................. 4-12
Adjusting the rear shock absorber
assembly ................................................ 4-17
PRE-OPERATION CHECKS ..........................5-1
Pre-operation check list ............................. 5-1
Fuel ............................................................ 5-4
Engine oil ................................................... 5-4
Coolant ...................................................... 5-4
Front and rear brakes ................................ 5-4
Throttle lever .............................................. 5-5
Drive chain ................................................. 5-5
Tires ........................................................... 5-5
Measuring the tire pressure ....................... 5-6
Tire wear limit ............................................ 5-7
Chassis fasteners ...................................... 5-8
Instruments, lights and switches ................ 5-8
OPERATION...................................................6-1
Starting a cold engine ................................ 6-1
Starting a warm engine .............................. 6-3
Shifting ....................................................... 6-3
Engine break-in .......................................... 6-5

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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Controls and instruments
NOTE:

The ATV you have purchased may differ slightly
from the figures shown in this manual.
1. Clutch lever
2. Handlebar switches
3. Parking brake
4. Main switch
5. Throttle lever
6. Brake lever
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heats. When this occurs during operation, stop the
engine as soon as it is safe to do so and allow it to
cool down for about 10 minutes.
The electrical circuit of the warning light can be
checked according to the following procedure.
1. Set the engine stop switch to “ ” and turn the
key to “ON”.
2. Shift the transmission into the neutral position
or pull the clutch lever.
3. Push the start switch. If the warning light does
not come on while the start switch is pushed,
have a Yamaha dealer check the electrical cir-
cuit.
CAUTION:

ECB00010

The engine may overheat if the ATV is over-
loaded. In this case, reduce the load to spec-
ification.

Start the engine after making sure that the
warning light is out. Continuous use while
the warning light is on may cause damage to
the engine.
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Handlebar switches
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Engine stop switch “ENG. STOP”
Set this switch to “RUN” before starting the engine.
The engine stop switch controls the ignition and
stops the engine when it is running. Use this switch
to stop the engine in an emergency situation. The
engine will not start or run when this switch is set
to “OFF”.
1. Light switch “LIGHTS”
2. Engine stop switch “ENG. STOP”
3. Start switch “START”
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(See page 8-30.)
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Clutch lever
The clutch lever is located on the left handlebar
and the ignition circuit cut-off system is incorporat-
ed in the clutch lever holder. To disengage the
clutch, pull the clutch lever toward the handlebar
grip. To engage the clutch, release the clutch lever.
The clutch lever should be pulled rapidly and re-
leased slowly for smooth clutch operation. (See
page 6-1 for a description of the ignition circuit cut-
off system.)
EBU18411
Brake lever
The brake lever is located at the right handlebar
grip. To apply the front brake, pull the brake lever
toward the handlebar grip.
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Brake pedal
The brake pedal is located on the right side of the
ATV. To apply the rear brake, push down on the
brake pedal.
1. Clutch lever
1. Brake lever
2. Locknut
3. Brake lever position adjusting bolt
4. Distance between brake lever and handlebar grip
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WARNING

EWB00220

Always set the parking brake before starting
the engine. The ATV could start moving un-
expectedly if the parking brake is not ap-
plied. This could cause loss of control or a
collision.

Always be sure you have released the park-
ing brake before you begin to ride. The brake
could overheat if you ride the ATV without re-
leasing the parking brake. You could lose
braking performance which could cause an
accident. You could also wear out the brakes
prematurely.
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Shift pedal
This ATV is equipped with a constant-mesh 5-
speed transmission. The shift pedal is located on
the left side of the engine and is used in combina-
tion with the clutch when shifting.
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Fuel tank cap
Remove the fuel tank cap by turning it counter-
clockwise.
1. Shift pedal
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Rear 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
Clutch

Check operation, and correct if necessary.

Lubricate cable if necessary.

Check lever free play, and adjust if necessary.8-39
Throttle lever

Make sure that operation is smooth. Lubricate cable and lever hous-
ing if necessary.

Check cable free play, and adjust if necessary.5-5, 8-30
Control cables

Make sure that operation is smooth. Lubricate if necessary. 8-41
Drive chain

Check chain slack, and adjust if necessary.

Check chain condition. Lubricate if necessary.5-5, , 8-41
Wheels and tires

Check wheel condition, and replace if damaged.

Check tire condition and tread depth. Replace if necessary.

Check air pressure. Correct if necessary.5-5, 5-6, 5-7
Brake and shift pedals

Make sure that operation is smooth. Lubricate pedal pivoting points
if necessary.8-43
Brake and clutch levers

Make sure that operation is smooth. Lubricate lever pivoting points
if necessary.8-42
Chassis fasteners

Make sure that all nuts, bolts and screws are properly tightened. 5-8
Instruments, lights and
switches

Check operation, and correct if necessary. 5-8
ITEM ROUTINE PAGE

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OPERATION
EBU19900
Read the Owner’s Manual carefully before riding
the ATV.
WARNING

EWB00630
Read the Owner’s Manual carefully to become
familiar with all controls in order to help pre-
vent any loss of control, which could cause an
accident or injury. If there is a control or func-
tion you do not understand, ask your Yamaha
dealer.
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Starting a cold engine
WARNING

EWB00640
Always make sure all control cables work
smoothly before you begin riding in cold
weather. If the control cables are frozen or do
not work smoothly, you could be unable to
control the ATV, which could lead to an acci-
dent or collision.
CAUTION:

ECB00150
See the “Engine break-in” section on page 6-5
prior to operating the engine for the first time.
1. Set the parking brake.
2. Turn the fuel cock to “ON”.
3. Turn the main switch to “ON” and the engine
stop switch to “RUN”.
4. Shift the transmission into neutral. The neutral
indicator light should come on. If the indicator
light does not come on, have a Yamaha deal-
er check the electrical circuit.
NOTE:

This model is equipped with an ignition circuit cut-
off system. The engine can be started under the
following conditions.

The transmission is in neutral.

The clutch is disengaged with the transmission
in gear. However, it is recommended to shift into
neutral before starting the engine.
5. Use the starter (choke) in reference to the fig-
ure: