Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionSpring Preload Adjustment
To adjust the spring preload, turn the spring preload adjuster
[A].
The standard adjuster setting is the 6 turns in from the
fully counterclockwise position.
WARNINGIf both adjusters are not adjusted
equally, handling
may be impaired and a hazardous condition may
result. B ...
Shifting Gears
Close the throttle while pulling in the
clutch lever.
Shift into the next higher or lower
gear.
Open the throttle part way, while releasing
the clutch lever.
For smooth riding, each gear position
should cover the proper rate of speed
shown in the table.
WARNINGDownshifti ...
Piston Installation
Apply molybdenum disulfide oil solution to the oil ring expander,
and install the oil ring expander [A] in the bottom
piston ring groove so the ends [B] not butt together
Applymolybdenum disulfide oil solution to the oil ring steel
rails, and install the oil ring steel rails, one above th ...