Yamaha WR426F(N) Owner's Service Manual page 608

FRONT FORK
EC554200
Base valve
1. Inspect:
Valve assembly 1
Wear/damage
O-ring 2
Damage
EC554400
Fork spring
1. Measure:
Fork spring free length a
Out of specification
Fork spring free length:
Standard
460 mm
(18.1 in)
EC554502
Inner tube
1. Inspect:
Inner tube surface a
Score marks
Use #1,000 grit wet sandpaper.
Damaged oil lock piece
Inner tube bends
Out of specification
Use the dial gauge 1.
Inner tube bending limit:
0.2 mm (0.008 in)
NOTE:
The bending value is shown by one half of the
dial gauge reading.
WARNING
Do not attempt to straighten a bent inner
tube as this may dangerously weaken the
tube.
EC554600
Outer tube
1. Inspect:
Outer tube 1
Score marks/wear/damage
5 - 32
CHAS
Replace.
Replace.
Replace.
<Limit>
455 mm
(17.9 in)
Repair or replace.
Replace.
Replace.
Replace.