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 InspectionSteering Damper Oil Leak Inspection
Visually inspect the steering damper [A] for oil leakage.
If the oil leakage is found on it, replace the steering
damper with a new one (see Steering Damper Removal/
Installation in the Steering chapter).
ZX1000JD/KD [B]
...
Drive Chain Wear Inspection
Remove the chain cover (see Drive Chain Removal/Installation
in the Final Drive chapter).
Rotate the rear wheel to inspect the drive chain for damaged
rollers, and loose pins and links
If there is any irregularity, replace the drive chain.
Lubricate the drive chain if it appears dry.
...
Throttle Control System
Check the throttle grip play each day
before riding the motorcycle, and carry
out maintenance and adjustments in
accordance with the Periodic Maintenance
Chart. Adjust it if necessary.
Throttle Grip
The throttle grip controls the butterfly
valves in the throttle body. If the throttle
grip ha ...