Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionMud Guard Installation
Installation is the reverse of removal. Note the following.
Run the hose and lead correctly (see Cable, Wire, and
Hose Routing section in the Appendix chapter).
Check the brake line.
Apply a non-permanent locking agent to the threads of
the mud guard mounting bolts [A, B], and tighten them ...
Brake Hose and Pipe Damage and Installation Condition Inspection
Inspect the brake hoses, pipes and fittings for deterioration,
cracks and signs of leakage.
The high pressure inside the brake line can cause fluid to
leak [A] or the hose to burst if the line is not properly maintained.
Bend and twist the rubber hose while examining
it.
Replace the ...
Starter Motor Installation
NOTICE
Do not tap the starter motor shaft or body. Tapping
the shaft or body could damage the motor.
Clean the starter motor legs [A] and crankcase where the
starter motor is ground.
Replace the O-ring [A] with a new one.
Apply grease to the new O-ring.
Tighten:
Torque - Starter ...