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 InspectionSeparator Operation Test
WARNINGGasoline is extremely flammable and can be
explosive
under certain conditions. Turn the ignition
switch OFF. Do not smoke. Make sure the area is
well-ventilated and free from any source of flame
or sparks; this includes any appliance with a pilot
light.
...
Connecting Rod Big End Side Clearance Inspection
Measure connecting rod big end side clearance.
Insert a thickness gauge [A] between the big end and either
crank web to determine clearance.
Connecting Rod Big End Side Clearance
Standard: 0.13 0.38 mm
(0.0051 0.0150 in.)
Service Limit: 0.58 mm (0.023 in.)
If the clearance exceeds ...
Vehicle-down Sensor Installation
Be sure to install the rubber dampers [A] and collars [B]
on the bracket.
The UP mark [A] of the sensor should face upward.
WARNINGIncorrect installation of the vehicle-down
sensor
could cause sudden loss of engine power. The
rider could lose balance during certain ...