2008 YAMAHA YFZ450 light

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

Replacing a headlight bulb ...................... 8-47
Adjusting a headlight beam ..................... 8-49
Replacing the tail/brake light bulb ........... 8-50
Removing a wheel ................................... 8-50
Installing a wheel ..................................... 8-50
Troubleshooting ...................................... 8-51
Troubleshooting charts ............................ 8-52
CLEANING AND STORAGE .......................... 9-1
Cleaning .................................................... 9-1
Storage ...................................................... 9-2
SPECIFICATIONS ...................................... 10-1
CONSUMER INFORMATION ...................... 11-1
Identification numbers ............................. 11-1

1-3
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ing, use the proper gear and maintain a steady
speed when climbing a hill. If you stall or roll
backwards, follow the special procedure for
braking described in this manual. Dismount on
the uphill side or to a side if pointed straight up-
hill. Turn the ATV around and remount, following
the procedure described in this manual.

Always check for obstacles before operating in a
new area.

Never attempt to operate over large obstacles,
such as large rocks or fallen trees. Always follow
proper procedures when operating over obsta-
cles as described in this manual.

Always be careful when skidding or sliding.
Learn to safely control skidding or sliding by
practicing at low speeds and on level, smooth
terrain. On extremely slippery surfaces, such as
ice, go slowly and be very cautious in order to re-
duce the chance of skidding or sliding out of con-
trol.

Never operate an ATV in fast flowing water or in
water deeper than that recommended in this
manual. Remember that wet brakes may have
reduced stopping ability. Test your brakes after
leaving water. If necessary, apply them several
times to let friction dry out the linings.

Always use the size and type of tires specified in
this manual.

Always maintain proper tire pressure as de-
scribed in this manual.

Never modify an ATV through improper installa-
tion or use of accessories.

Never exceed the stated load capacity for an
ATV. Cargo should be properly distributed and
securely attached. Reduce speed and follow in-
structions in this manual for carrying cargo or
pulling a trailer. Allow greater distance for brak-
ing.
WARNING

EWB00061

Always turn off the engine when refueling.

Do not refuel right after the engine has been
running and is still very hot.

Do not spill gasoline on the engine or ex-
haust pipe/muffler when refueling. Never re-
fuel while smoking, or in the vicinity of
sparks, open flames, or other sources of ig-
nition such as the pilot lights of water heat-
ers and clothes dryers. Gasoline can catch
fire and you could be burned.

When transporting the ATV in another vehi-
cle, be sure it is kept upright and that the fuel

3-1
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EBU17680
DESCRIPTION
EBU17690
Left view
EBU17700
Right view
1. Headlights
2. Fuel cock
3. Starter (choke)
4. Throttle stop screw
5. Fuse
6. Tail/brake light
7. Coolant reservoir
8. Shift pedal
9. Engine oil tank
1
23456
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8
9

1. Spark arrester
2. Seat
3. Fuel tank cap
4. Radiator cap
5. Oil filter element
6. Brake pedal1
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5 6

3-2
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EBU17712
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
2
123456

4-1
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EBU17730
INSTRUMENT AND CONTROL FUNCTIONS
EBU17740
Main switch
The positions of the main switch are as follows:
ON
All electrical systems are supplied with power, and
the engine can be started. The key cannot be re-
moved.
OFF
All electrical systems are off. The key can be re-
moved.

EBU17802
Indicator light and warning light
EBU17860
Neutral indicator light “”
This indicator light comes on when the transmis-
sion is in the neutral position.
EBU17930
Coolant temperature warning light “”
This warning light comes on when the engine over-
1. Main switch
OFF ON
1

1. Neutral indicator light “N”
2. Coolant temperature warning light “ ”
12

4-2
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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.
EBU18060
Handlebar switches
EBU18070
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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