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 InspectionExhaust Pipe Removal
Remove:
Radiator (see Radiator and Radiator Fan Removal in the
Cooling System chapter)
Exhaust Pipe Clamp Bolt [A] (Loosen)
Remove the exhaust pipe holder nuts [A], and pull out the
exhaust pipe [B] forward from the premuffler chamber.
...
Idle Speed
The idle speed inspection should be
performed in accordance with the Periodic
Maintenance Chart.
This motorcycle is equipped with the
Idle Speed Control valve. If the idle
speed is disturbed, inspection of the
idle speed control should be done by
an authorized Kawasaki dealer.
NOTE
While ...
Throttle Control System Inspection
Check the throttle grip free play [A].
If the free play is incorrect, adjust the throttle cables.
Throttle Grip Free Play
Standard: 2 3 mm (0.08
0.12 in.)
Check that the throttle grip [B] moves smoothly from full
open to close, and the throttle closes quickly and completely
by the ...