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 DiscValve Clearance Inspection
NOTE
Valve clearance must be checked and adjusted when
the engine is cold (at room temperature).
Remove:
Crankshaft Sensor Cover (see Crankshaft Sensor Removal
in the Electrical System chapter)
Cylinder Head Cover (see Cylinder Head Cover Removal
in the Engine Top End chapter)
Turn t ...
Coupling Bearing Installation
Replace the bearing with a new one.
Press in the bearing [A] until it is bottomed.
Special Tool - Bearing Driver Set [B]: 57001-1129
Pack the bearing with high-temperature grease.
Replace the circlip with a new one.
Special Tool - Inside Circlip Pliers: 57001-143
Replace the grease se ...
Connecting Rod Installation
NOTICE
To minimize vibration, the connecting rods should
have the same weight mark.
Big End Cap [A]
Connecting Rod [B]
Weight Mark, Alphabet [C]
Diameter Mark [D] (“” or No Mark)
NOTICE
If the connecting rods, big end bearing inserts, or
crankshaft are replaced with new ones, select ...