Use the micrometer to measure at several points around the ring.
Piston Ring Thickness Standard:
Top [A] 0.77
0.79 mm (0.0303
0.0311 in.)
Second [B] 0.78
0.79 mm
(0.0307
0.0311 in.)
Service Limit:
Top 0.70 mm (0.0276 in.)
Second 0.71 mm (0.0280 in.)

If any of the measurements is less than the service limit on either of the rings, replace all the rings.
NOTE
When using new rings in a used piston, check for uneven groove wear. The rings should fit perfectly parallel to the groove sides. If not, replace the piston.
Piston Ring Groove Width Inspection
Piston Ring End Gap InspectionShifting Gears
Close the throttle while pulling in the
clutch lever.
Shift into the next higher or lower
gear.
Open the throttle part way, while releasing
the clutch lever.
For smooth riding, each gear position
should cover the proper rate of speed
shown in the table.
WARNINGDownshifti ...
ECU Identification
Most countries have their own regulations, so each ECU
has different characteristic. So, do not confuse ECU with
each other and use only the ECU for your model. Otherwise,
the motorcycle can not clear the regulation.
ECU Identification
ZX1000JB/KB
ZX1000JC /KC
...
Fuse Inspection
Remove the fuse.
Inspect the fuse element.
If it is blown out, replace the fuse. Before replacing a
blown fuse, always check the amperage in the affected
circuit. If the amperage is equal to or greater than the
fuse rating, check the wiring and related components for
a short circuit.
...