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 InspectionEngine Sprocket Installation
Replace the sprocket washer and axle cotter pin.
Install the engine sprocket onto the output shaft.
Apply molybdenum disulfide oil solution to the threads
and seating surface of the engine sprocket nut.
Tighten:
Torque - Engine Sprocket Nut: 145 N·m (14.8 kgf·m, 107
ft·lb)
NOTE
...
Front Forks/Rear Shock Absorber Operation Inspection
Pump the forks down and up [A] 4 or 5 times, and inspect
the smooth stroke.
If the forks do not smoothly or noise is found, inspect the
fork oil level or fork clamps (see Front Fork Oil Change in
the Suspension chapter).
Pump the rear seat down and up [A] 4 or 5 times, and
inspec ...
Camshaft Removal
Remove:
Cylinder Head Cover (see Cylinder Head Cover Removal)
Crankshaft Sensor Cover (see Crankshaft Sensor Removal
in the Electrical System chapter)
Using a wrench on the timing rotor bolt [A], turn the crankshaft
clockwise until the line [B] (TDC mark for #1,4 pistons)
on the timin ...