Yamaha YZ450F 2021, Owner'S Service Manual

Page: 104 / 368

CHASSIS
3-28
5. Install:
• Upper bracket
Refer to “STEERING HEAD” on page 4-55.
• Handlebar
Refer to “HANDLEBAR” on page 4-35.
EAM30502
LUBRICATING THE STEERING HEAD
1. Lubricate:
• Upper bearing
• Lower bearing
• Bearing race
EAM30338
CHECKING THE FRONT FORK LEGS
1. Stand the vehicle upright on a level surface.
WARNING
EWA13120
Securely support the vehicle so that there is
no danger of it falling over.
2. Check:
•
Inner tube
Damage/scratches

Replace.
•
Front fork leg
Oil leaks between inner tube and outer tube

Replace the oil seal.
3. Hold the vehicle upright and apply the front
brake.
4. Check:
•
Front fork operation
Push down hard on the handlebar several
times and check if the front fork rebounds
smoothly.
Unsmooth operation

Correct or replace.
Refer to “FRONT FORK” on page 4-42.
5. Check:
• Protector guide “1”
Out of specification

Replace.
TIP
The protector guide reaches the limit of its use
when it is worn down to the same height “a” as
of the outer tube circumference.
6. Remove:
• Protector
•
Dust seal “1”
NOTICE
ECA24330
Be careful not to damage the dust seal and
the inner tube by a driver.
7. Clean:
•
Dust seal “a”
• Oil seal “b”
TIP
•
Clean the dust seal and oil seal after every run.
• Apply lithium-soap-based grease on the inner
tube.
EAM30239
ADJUSTING THE FRONT FORK LEGS
WARNING
EWA19180
• Always adjust the left and right front forks
evenly. If this is not done, the vehicle may
Recommended lubricant
Lithium-soap-based grease
1
1
a
1
LS
a
b