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 InspectionHub Bearing Installation
Before installing the hub bearings, blow any dirt or foreign
particles out of the hub with compressed air to prevent
contamination of the bearings.
Replace the bearings with new ones.
Install the bearings by using the bearing driver set which
does not contact the bearing inner race.
...
Spring Preload Adjustment
Remove the rear shock absorber from the frame (see
Rear Shock Absorber Removal).
Loosen the locknut and turn out the adjusting nut to free
the spring.
Special Tools - Hook Wrench T=3.2 R37: 57001-1539
Hook Wrench R=35: 57001-1580
To adjust the spring preload, turn in the adjusting n ...
Crankcase Halves Assembly
Install:
Crankshaft (see Crankshaft Installation)
Connecting Rods (see Connecting Rod Installation)
Using a cleaning fluid, clean off any oil or dirt on the mating
surface of the crankcase halves.
Apply liquid gasket to the mating surface of the lower
crankcase half as shown in the fi ...