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

Shift Fork Guide Pin/Drum Groove Wear InspectionOxygen Sensor Heater Resistance Inspection
Turn the ignition switch to OFF.
Remove the fuel tank (see Fuel Tank Removal in the Fuel
System (DFI) chapter).
Disconnect the oxygen sensor lead connector [A].
Connect a digital meter [A] to the terminals in the oxygen
sensor lead connector [B].
Measure the oxygen sensor heat ...
Tachometer
The tachometer shows the engine
speed in revolutions per minute (r/min,
rpm).
On the right side of the tachometer
face is a portion called the “red zone”.
Engine r/min (rpm) in the red zone is
above maximum recommended engine
speed and is also above the range for
good performance.
...
Rear Sprocket Removal
Remove the rear wheel (see Rear Wheel Removal in the
Wheels/Tires chapter).
NOTICE
Do not lay the wheel on the ground with the disc
facing down. This can damage or warp the disc.
Place blocks under the wheel so that the disc does
not touch the ground.
Remove:
Rear Sprocket Nu ...