If the teeth are worn as illustrated, replace the sprocket, and inspect the drive chain wear (see Drive Chain Wear Inspection in the Periodic Maintenance chapter).
Worn Tooth (Engine Sprocket) [A] Worn Tooth (Rear Sprocket) [B] Direction of Rotation [C]
NOTE
If a sprocket requires replacement, the chain is probably worn also. When replacing a sprocket, inspect the chain.

Coupling Damper Inspection
Rear Sprocket Warp InspectionClutch Cover Assembly
Replace the needle bearings and oil seal with new ones.
NOTE
Install the needle bearings so that the manufacture’s
mark face out.
Install the needle bearings [A] and oil seal [B] position as
shown in the figure.
Press the upper and lower bearings so that the bearing
surface [ ...
Transmission Assy Assembly
Install the ball bearing [A] until it is bottomed.
Turn the oil seal side to the bottom.
Special Tool - Bearing Driver Set: 57001-1129
Install the bearing holder [B].
Turn the flat side to the bottom.
Apply a non-permanent locking agent to the bearing
holder bolts [C].
Tighten: ...
Crankcase Splitting
Remove the engine (see Engine Removal in the Engine
Removal/Installation chapter).
Set the engine on a clean surface and hold the engine
steady while parts are being removed.
Remove:
Cylinder Head (see Cylinder Head Removal in the Engine
Top End chapter)
Starter Motor (see Starter M ...