Special Tool - Outside Circlip Pliers: 57001-144
The 5th gear [A] on the output shaft has three steel balls assembled into it for the positive neutral finder mechanism.
Remove the 5th gear as follows.

Set the output shaft in a vertical position holding the 3rd gear [B].
Spin the 5th gear quickly [C] and pull it off upward.
Transmission Assy Installation
Transmission Shaft AssemblyOil Pressure Switch Installation
Using a high flash-point solvent, clean off any oil or dirt
that may be on the silicone sealant coating area. Dry
them with a clean cloth.
Apply silicone sealant to the threads of the oil pressure
switch, and tighten it.
Sealant - Liquid Gasket, TB1211: 56019-120
Torque - Oil Pressure ...
Chain Slack Inspection
Set the motorcycle up on its side
stand.
Rotate the rear wheel to find the position
where the chain is tightest, and
measure the maximum chain slack
by pulling up and pushing down the
chain midway between the engine
sprocket and rear wheel sprocket.
A. Chain Slack
If the ...
Engine Sprocket Installation
Replace the sprocket washer and axle cotter pin.
Install the engine sprocket onto the output shaft.
Apply molybdenum disulfide oil solution to the threads
and seating surface of the engine sprocket nut.
Tighten:
Torque - Engine Sprocket Nut: 145 N·m (14.8 kgf·m, 107
ft·lb)
NOTE
...