Yamaha YZ450FP 2023, Owner'S Service Manual

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FRONT FORK
4-49
5. Remove:
• Adjuster knob
•
Base valve “1”
(from the damper assembly)
TIP
•
Before loosening the damping force adjuster,
record the setting position.
•
Unless the damping force adjuster is fully loos-
ened, correct damping characteristic cannot be
obtained after installation.
• Hold the damper assembly with the cap bolt
ring wrench “2” and use the cap bolt wrench “3”
to remove the base valve.
EAM30057
CHECKING THE FRONT FORK LEGS
1. Check:
• Inner tube surface
Scratches

Repair or replace.
Use #1000 grit wet sandpaper.
Damaged oil lock piece

Replace.
• Inner tube bends
Out of specification

Replace.
Use the dial gauge.
TIP
The bending value is shown by one half of the
dial gauge reading.
WARNING
EWA13650
Do not attempt to straighten a bent inner
tube as this may dangerously weaken it.
2. Check:
•
Outer tube
Scratches/wear/damage

Replace.
3. Measure:
• Fork spring free length “a”
Out of specification

Replace.
4. Check:
•
Damper assembly “1”
Bend/damage

Replace.
•
O-ring “2”
Wear/damage

Replace.
NOTICE
ECA14200
• The front fork leg has a built-in damper ad-
justing rod and a very sophisticated inter-
nal construction, which are particularly
sensitive to foreign material.
• When disassembling and assembling the
front fork leg, do not allow any foreign ma-
terial to enter the front fork.
Cap bolt wrench
90890-01911
Cap bolt ring wrench
90890-01501
Cap bolt ring wrench
YM-01501
1
2
3
Inner tube bending limit
0.2 mm (0.01 in)
Fork spring free length limit
492.0 mm (19.37 in)