If there are notches worn into the splines, replace the sub clutch hub. Also, replace the steel plates if their teeth are damaged.

Clutch Housing Finger Inspection
Damper Cam InspectionRocker Arm Installation
Install the both rocker arms [A] so that their marks [B] face
left side.
Replace the tie-rod nut, rear shock absorber nut and
rocker arm nut with new ones.
Apply grease to the inside of the oil seals.
Tighten:
Torque - Rocker Arm Nut: 34 N·m (3.5 kgf·m, 25 ft·lb)
Tie-Rod ...
Steering 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]
...
Crankshaft Sensor Inspection
Disconnect the crankshaft sensor lead connector (see
Crankshaft Sensor Removal).
Set the hand tester [A] to the × 10 Ω range and connect it
to the crankshaft sensor lead connector [B].
Special Tool - Hand Tester: 57001-1394
Crankshaft Sensor Resistance
Connections:
Meter (+ ...