Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionAir Suction Valve Inspection
Remove the air suction valve (see Air Suction Valve Removal).
Visually inspect the reeds [A] for cracks, folds, warps,
heat damage or other damage.
If there is any doubt as to the condition of the reeds, replace
the air suction valve as an assembly.
Check the reed contact areas [B] of ...
Swingarm Installation
Visually inspect the chain guide [A].
Replace the chain guide if it shows any signs of abnormal
wear or damage.
Apply a non-permanent locking agent to the threads of
the chain guide bolt [B].
Apply plenty of grease to the lip of the oil seals [A].
Be sure to install the oil seals ...
Wheel Rotation Sensor Rotor Inspection
Remove:
Wheels (see Front/Rear Wheel Removal in the
Wheels/Tires chapter)
Brake Disc Mounting Bolts [A]
Sensor Rotor [B]
Front Wheel [C]
Rear Wheel [D]
Visually inspect the wheel rotation sensor rotor.
If the rotor is deformed or damaged (chipped teeth [A]),
replace the ...