2008 YAMAHA YFZ450 air filter

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

4-18
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3. Disconnect the hose, and then remove the air
filter case by removing the bolts.
1. Clamp screw
1

1. Hose
1

4-20
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2
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(0.06 in). 6. Tighten the locknut to the specified torque.CAUTION:
ECB00080
Always tighten the locknut against the adjust-
ing nut, and then tighten it to the specified
torque.
7. Place the air filter case in the original position,
connect the air intake duct, and then tighten
the clamp screw at the carburetor side.
8. Install the bolts, and then connect the hose.
9. Install the seat.
Rebound damping force
Turn the adjusting screw in direction (a) to increase
the rebound damping force and thereby harden
the damping, and in direction (b) to decrease the
rebound damping force and thereby soften the
damping. Spring preload setting:
Minimum (hard):
Distance A = 250.0 mm (9.84 in)
Standard:
Distance A = 257.0 mm (10.12 in)
Maximum (soft):
Distance A = 265.0 mm (10.43 in)

1. Distance A
1

Tightening torque:
Locknut:
44 Nm (4.4 m·kgf, 33 ft·lbf)

7-19
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67
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in water deeper than that specified in your
Owner’s 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 lin-
ings. If the ATV is operated through deep or
fast flowing water, the tires may float, causing
loss of traction and loss of control, which
could lead to an accident.
Test your brakes after leaving the water. Do not
continue to ride your ATV without verifying that youhave regained proper braking ability.CAUTION:
ECB00240
After riding your ATV in water, be sure to drain
the trapped water by removing the check hose
at the bottom of the air filter case. Wash the
ATV in fresh water if it has been operated in
salt water or muddy conditions.

8-8
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EBU23070
NOTE:


The air filter needs more frequent service if you are riding in unusually wet or dusty areas.

Hydraulic brake service

Regularly check and, if necessary, correct the brake fluid level.

Every two years replace the internal components of the brake master cylinders and calipers, and
change the brake fluid.

Replace the brake hoses every four years and if cracked or damaged.

8-24
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otherwise the engine may not be sufficiently
cooled and the cooling system will not be
protected against frost and corrosion.

If water has been added to the coolant, have
a Yamaha dealer check the antifreeze con-
tent of the coolant as soon as possible, oth-
erwise the effectiveness of the coolant will
be reduced.
12. Install the radiator cap, start the engine, let it
idle for several minutes, and then turn it off.
13. Remove the radiator cap to check the coolant
level in the radiator. If it is low, add sufficient
coolant until it reaches the top of the radiator,
and then install the radiator cap.
14. Start the engine, and then check for coolant
leakage.
NOTE:

If any leakage is found, have a Yamaha dealer
check the cooling system.
15. Install the panel.
EBU23702
Cleaning the air filter element
The air filter element should be cleaned at the in-
tervals specified in the periodic maintenance andlubrication chart. Clean the air filter element more
frequently if you are riding in unusually wet or dusty
areas.
NOTE:

There is a check hose at the bottom of the air filter
case. If dust or water collects in this hose, empty
the hose and clean the air filter element and air fil-
ter case.
1. Remove the seat. (See page 4-11.)
2. Remove the air filter case cover by unhooking
the holders.
1. Air filter case check hose
1

8-25
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3. Loosen the wing bolt.
4. Remove the air filter element together with the
wing bolt and washer.5. Remove the wing bolt and washer from the air
filter element.
6. Remove the sponge material from the air filter
element frame.
1. Air filter case cover
2. Air filter case holder
2 1

1. Wing bolt
2. Sponge material
1 2

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7. Wash the sponge material gently but thor-
oughly in solvent.
WARNING

EWB01940
Always use parts cleaning solvent to clean the
sponge material. Never use low-flash-point
solvents or gasoline to clean the sponge mate-
rial because the engine could catch fire or ex-
plode.
8. Squeeze the excess solvent out of the sponge
material and let it dry.CAUTION:

ECB00440
Do not twist the sponge material when squeez-
ing it.
9. Check the sponge material and replace it if
damaged.
10. Apply a quality foam air filter oil to the sponge
material.
NOTE:

The sponge material should be wet but not drip-
ping.
11. Pull the sponge material over the air filter ele-
ment frame.
1. Sponge material
2. Air filter element frame
1 2