If the shaft is bent, straighten or replace it.
If the serration [B] are damaged, replace the shaft.
If the spring [C] is damaged in any way, replace it.
If the shift mechanism arm [D] is damaged in any way, replace the shaft.

If the ratchet [A], pawls [B], pins [C] or springs [D] are damaged in any way, replace them.

If it is loose, unscrew it, apply a non-permanent locking agent to the threads, and tighten it.
Torque - Shift Shaft Return Spring Pin: 29 N·m (3.0 kgf·m, 21 ft·lb)
If the lever or spring are damaged in any way, replace them.
If they are badly worn or if they show any damage, replace it.

External Shift Mechanism Installation
Wheels/TiresCrankshaft Removal
Split the crankcase (see Crankcase Splitting).
Remove:
Connecting Rod Big End Nuts [A]
Connecting Rod Big End Caps [B]
NOTE
Mark and record the locations of the connecting rods
and their big end caps so that they can be reassembled
in their original positions.
Remove the crank ...
Alternator Rotor Removal
Remove the alternator cover (see Alternator Cover Removal).
Clean off the oil from the outer circumference of the rotor.
Hold the alternator rotor steady with the rotor holder [A]
and suitable washer or plate [B].
Special Tools - Grip [C]: 57001-1591
Rotor Holder: 57001-1666
Flywheel P ...
Special Tools and Sealant
Oil Pressure Gauge, 10 kgf/cm²:
57001-164
Oil Pressure Gauge Adapter, PT3/8:
57001-1233
Outside Circlip Pliers:
57001-144
Liquid Gasket, TB1211:
56019-120
...