Yamaha YZ450FF 1SL-28199-11, Owner'S Service Manual

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FRONT FORK
4-41
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5. Remove:
• Base valve “1”
(from the damper assembly)
TIP
Hold the damper assembly with the cap bolt
ring wrench “2” and use the cap bolt wrench “3”
to remove the base valve.
EAS1SL5170 CHECKING THE FRONT FORK LEGS
1. Check:
• Inner tube surface “a”
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 “1”.
TIP
The bending value is shown by one half of the
dial gauge reading.
EWA13650
WARNING
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.
ECA1DX1010
NOTICE
• 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
90890-01500
YM-01500
Cap bolt ring wrench
90890-01501
YM-01501
Inner tube bending limit
0.2 mm (0.01 in)
1
2
3
Fork spring free length
497.0 mm (19.57 in)
Limit
492.0 mm (19.37 in)