Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionBalance Inspection
Remove the front and rear wheels (see Front/Rear Wheel
Removal).
Support the wheel so that it can be spun freely.
Spin the wheel lightly, and mark [A] the wheel at the top
when the wheel stops.
Repeat this procedure several times. If the wheel stops
of its own accord in various positi ...
Steering Stem Warp Inspection
Whenever the steering stem is removed, or if the steering
can not be adjusted for smooth action, check the steering
stem for straightness.
If the steering stem [A] is bent, replace the steering stem.
Stem Cap Deterioration, Damage Inspection
Replace the stem cap if its oil seal [A] s ...
Valve Guide Installation
Apply engine oil to the valve guide outer surface before
installation.
Heat the area around the valve guide hole to about 120
150°C (248 302°F).
NOTICE
Do not heat the cylinder head with a torch. This will
warp the cylinder head. Soak the cylinder head and
heat the oil.
Usin ...