The rings should fit perfectly parallel to groove surfaces.
If not, replace the piston and all the piston rings.

Piston Ring/Groove Clearance Standard:
Top 0.03
0.07 mm (0.0012
0.0028 in.)
Second 0.03
0.06 mm (0.0012
0.0024 in.)
Service Limit:
Top 0.17 mm (0.0067 in.)
Second 0.16 mm (0.0063 in.)
Piston Wear Inspection
Piston Ring Groove Width InspectionCooling System Flushing
Over a period of time, the cooling system accumulates
rust, scale, and lime in the water jacket and radiator. When
this accumulation is suspected or observed, flush the cooling
system. If this accumulation is not removed, it will clog
up the water passage and considerable reduce the efficiency
...
Spring Plate Free Play Measurement
Insufficient clutch free play will cause the engine braking
effect to be more sudden, resulting in rear wheel hop. On
the other hand, if the free play is excessive, the clutch lever
may feel “spongy” or pulsate when pulled.
Hold an extra drive shaft in a vise and install the following
c ...
Exhaust Butterfly Valve Actuator Sensor Input Voltage Inspection
NOTE
Be sure the battery is fully charged.
Turn the ignition switch to OFF.
Remove the front seat (see Front Seat Removal in the
Frame chapter).
Remove the screws [A] and the exhaust butterfly valve
actuator temporarily with the cables installed.
Disconnect the exhaust butterf ...