Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionPiston Ring Groove Width Inspection
Measure the piston ring groove width.
Use a vernier caliper at several points around the piston.
Piston Ring Groove Width
Standard:
Top [A] 0.82 0.84 mm (0.0323
0.0331 in.)
Second [B] 0.82 0.84 mm
(0.0323 0.0331 in.)
Service Limit:
0.92 mm (0.036 in.)
Second 0.92 mm (0.036 in.)
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Exhaust Butterfly Valve Cable Installation
Confirm whether pulley [A] is an angle shown in the figure.
41.7° ±7° [B]
This position is original position of the pulley.
NOTE
Correct the position electrically after confirming the use
is discontinued and there is no damage when differing
from the angle of shown in the figure.
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Moving Off
Check that the side stand is up.
Pull in the clutch lever.
Shift into 1st gear.
Open the throttle a little, and start to
let out the clutch lever very slowly.
As the clutch starts to engage, open
the throttle a littlemore, giving the engine
just enough fuel to keep it from
stallin ...