Yamaha YZ450FY 2009 Owner's Service Manual page 91

A. Right
B. Left
Turn the adjuster so that the drive chain is in
line with the sprocket, as viewed from the rear.
d. Tighten the axle nut while pushing down the
drive chain.
Axle nut:
135 Nm (13.5 m•kg, 98 ft•lb)
e. Tighten the locknuts.
Locknut:
19 Nm (1.9 m•kg, 13 ft•lb)
CHECKING THE FRONT FORK
1. Inspect:
• Front fork smooth action
Operate the front brake and stroke the front
fork.
Unsmooth action/oil leakage → Repair or re-
place.
CLEANING THE FRONT FORK OIL SEAL
AND DUST SEAL
1. Remove:
• Protector
• Dust seal "1"
Use a thin screw driver, and be careful not to
damage the inner fork tube and dust seal.
2. Clean:
• Dust seal "a"
• Oil seal "b"
• Clean the dust seal and oil seal after every
run.
• Apply the lithium soap base grease on the in-
ner tube.
RELIEVING THE FRONT FORK INTERNAL
PRESSURE
If the front fork initial movement feels stiff dur-
ing a run, relieve the front fork internal pres-
sure.
1. Elevate the front wheel by placing a suitable
stand under the engine.
2. Remove the air bleed screw "1" and release
the internal pressure from the front fork.
3. Install:
• Air bleed screw
Air bleed screw:
1 Nm (0.1 m•kg, 0.7 ft•lb)
3-26
CHASSIS