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 InspectionFlap and Rear Fender Rear Removal
Remove:
Front and Rear Seat (see Front/Rear Seat Removal)
Seat Covers (see Seat Cover Removal)
Vehicle-down Sensor Connector [A]
Screws [B]
Clear the seat lock cable [C] from the seat lock unit [D].
Take off the seat lock unit and the bracket.
Remove:
Bolts [A] (Both Sides ...
Wiring Diagram (Other than US, CA and CAL with KIBS Models)
ZX1000KC
ZX1000KD
...
Front Fork Removal (Each Fork Leg)
Loosen the front fork top plug [A] beforehand if the fork
leg is to be disassembled.
Special Tool - Top Plug Wrench (45 mm) [B]: 57001-1741
NOTE
Loosen the top plug after loosening the handlebar
clamp bolt [C] and upper front fork clamp bolt [D].
Remove:
Upper Fairing Assembly (see Up ...