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.)

If the width of any of the two grooves is wider than the service limit at any point, replace the piston.
Piston Ring, Piston Ring Groove Wear Inspection
Piston Ring Thickness InspectionLighting System
This motorcycle adopt the daylight system and have a
headlight relay in the relay box. The headlight does not
go on when the ignition switch and the engine stop switch
are first turned on. The headlight comes on after the starter
button is released and stays on until the ignition switch is
turn ...
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 ...
Air Switching Valve (Service Code 64)
Air Switching Valve Removal/Installation
Refer to the Air Switching Valve Removal/Installation in
the Engine Top End chapter.
Air Switching Valve Inspection
Refer to the Air Switching Valve Unit Test in the Electrical
System chapter.
If the air switching valve [A] is normal, check ...