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/TiresPiston Wear Inspection
Measure the outside diameter [A] of each piston 5 mm
(0.20 in.) [B] up from the bottom of the piston at a right
angle to the direction of the piston pin.
If the measurement is under service limit, replace the piston.
Piston Diameter
Standard: 75.959 75.974 mm
(2.9905 2.9911 in.)
...
Master Cylinder Inspection (Visual Inspection)
Remove the master cylinders (see Front/Rear Master
Cylinder Removal).
Disassemble the front and rear master cylinders (see
Master Cylinder Rubber Parts Replacement in the Periodic
Maintenance chapter).
Check that there are no scratches, rust or pitting on the
inner wall [A] of each ma ...
Sidestand Switch Operation Inspection
Raise the rear wheel off the ground with the stand (see
Rear Wheel Removal in the Wheels/Tires chapter).
Inspect the sidestand switch [A] operation accordance to
below table.
Sidestand Switch Operation
If the sidestand switch operation does not work, inspect
or replace the foll ...