Replace any damaged gears or gears with excessively worn dogs or dog holes.

Shift Fork Guide Pin/Drum Groove Wear InspectionStarter Motor Installation
NOTICE
Do not tap the starter motor shaft or body. Tapping
the shaft or body could damage the motor.
Clean the starter motor legs [A] and crankcase where the
starter motor is ground.
Replace the O-ring [A] with a new one.
Apply grease to the new O-ring.
Tighten:
Torque - Starter ...
Engine Sprocket Installation
Replace the sprocket washer and axle cotter pin.
Install the engine sprocket onto the output shaft.
Apply molybdenum disulfide oil solution to the threads
and seating surface of the engine sprocket nut.
Tighten:
Torque - Engine Sprocket Nut: 145 N·m (14.8 kgf·m, 107
ft·lb)
NOTE
...
Radiator Hose and O-ring Replacement
Drain the coolant (see Coolant Change).
Remove:
Upper Fairing Assembly (see Upper Fairing Assembly
Removal in the Frame chapter)
Thermostat Housing [A] (see Thermostat Removal in the
Cooling System chapter)
Oil Cooler [B] (see Oil Cooler Removal in the Engine
Lubrication System chap ...