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 InspectionClutch
Due to friction plate wear and clutch
cable stretch over a long period of use,
the clutch operation should be checked
each day before riding the motorcycle,
and must be adjusted in accordance
with the Periodic Maintenance Chart.
Inspection
Check that the clutch lever operates
properly an ...
Handlebar Removal
Remove:
Steering Damper (see Steering Damper Removal)
Clutch Lever Clamp Bolts [A]
Clutch Lever Assembly [B]
Left Switch Housing [C]
Handlebar Weight [D]
Left Handlebar Grip [E]
Remove:
Front Master Cylinder [A] (see Front Master Cylinder Removal
in the Brakes chapter)
...
Steering Stem Warp Inspection
Whenever the steering stem is removed, or if the steering
can not be adjusted for smooth action, check the steering
stem for straightness.
If the steering stem [A] is bent, replace the steering stem.
Stem Cap Deterioration, Damage Inspection
Replace the stem cap if its oil seal [A] s ...