If a master cylinder or piston shows any damage, replace them.

If a cup is worn, damaged softened (rotted), or swollen, the piston assembly should be replaced to renew the cups.
If fluid leakage is noted at the brake lever, the piston assembly should be replaced to renew the cups.
If they are damaged, replace them.
If the springs are damaged, replace them.
If the relief port becomes plugged, the brake pads will drag on the disc. Blow the ports clean with compressed air.
Front Master Cylinder [I] Rear Master Cylinder [J]

Rear Master Cylinder Installation
Brake DiscChassis Parts Lubrication
Before lubricating each part, clean off any rusty spots with
rust remover and wipe off any grease, oil, dirt, or grime.
Lubricate the points listed below with indicated lubricant.
NOTE
Whenever the vehicle has been operated under
wet or rainy conditions, or especially after using a
high ...
Compression Damping Force Adjustment
There are two adjustments you can make to the compression
damping force.
High Speed Compression Damping Adjuster [A]
Low Speed Compression Damping Adjuster [B]
To adjust the high speed compression damping force, turn
the outside damping adjuster with a wrench to the desired
position ...
Transmission Assy Installation
Assemble the transmission assy (see Transmission Assy
Assembly).
Be sure that the dowel pins are in position.
Install the transmission assy on the crankcase.
Tighten:
Torque - Transmission Case Bolts: 20 N·m (2.0 kgf·m, 15
ft·lb)
Install:
Shift Shaft (see External Shift Mechani ...