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/TiresConnecting Rod Big End
Bearing Insert/Crankpin Wear Inspection
Remove the connecting rod big end (see Connecting Rod
Removal).
Cut strips of plastigage to crankpin width. Place a strip
on the crankpin parallel to the crankshaft installed in the
correct position.
Tighten the connecting rod big end nuts to the specified
torque (see Connecting Rod I ...
Piston 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.)
...
Clutch Installation
Apply engine oil to the needle bearing [A] and the sleeve
[B].
Install:
Needle Bearing
Sleeve
Install the clutch housing [A].
Fit the holes [B] and projections [C].
Engage the clutch housing gear and the crankshaft primary
gear.
Install the spacer [A] and the clutch ...