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 InspectionESD (Electronic Steering Damper) ECU Communication Error (Service Code 3C,
ZX1000JD/KD)
ESD ECU Communication Line Inspection
When the data (for status of ESD system) is not sent from
the ESD ECU to the meter unit and ECU, the service code
3C is displayed.
The data is sent through the CAN communication line.
The service code 3C is detected with the meter unit.
The FI symbol does ...
Throttle Body Assy Installation
Apply a thin coat of grease to the throttle cable lower ends.
Fit the accelerator cable end [A] and the decelerator cable
end [B] into the throttle pulley.
Install the clamp [C] securely.
Install the throttle body assy holder clamp bolt heads [A]
outside as shown in the figure.
...
Crankshaft Main Bearing
Insert/Journal Wear Inspection
Split the crankcase (see Crankcase Splitting).
Cut strips of plastigage to journal width.
Place a strip on each journal parallel to the crankshaft
installed in the correct position.
Tighten the crankcase bolts to the specified torque (see
Crankcase Assembly).
NOTE
Do not turn ...