Checking The Front Fork Legs; Checking The Front Fork Protector Guide; Cleaning The Front Fork Oil Seal And Dust Seal; Air Bleeding From Front Fork - Yamaha YZ450FX 2019 Owner's Service Manual

Drive chain puller locknut
21 N·m (2.1 kgf·m, 15 lb·ft)
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EAM30338

CHECKING THE FRONT FORK LEGS

1. Stand the vehicle upright on a level surface.
EWA13120
WARNING
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 4-38.
EAM30236
CHECKING THE FRONT FORK PROTECTOR
GUIDE
1. 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.
EAM30237
CLEANING THE FRONT FORK OIL SEAL
AND DUST SEAL
1. Remove:
• Protector
• Dust seal "1"
ECA24330
NOTICE
Be careful not to damage the dust seal and
the inner tube by a driver.
1
2. 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.
b
LS
EAM30238

AIR BLEEDING FROM FRONT FORK

TIP
If the front fork initial movement feels stiff during
3-28
CHASSIS
1
a
a