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 DiscCaliper Rubber Parts Replacement
Front Caliper Disassembly
Remove:
Front Caliper (see Front Caliper Removal in the Brakes
chapter)
Brake Pads (see Front Brake Pad Removal in the Brakes
chapter)
Remove:
Front Caliper Assembly Bolts [A]
Split the front caliper.
Remove:
Pad Spring
O-ring [A]
U ...
Oil 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 ...
Air Cleaner
A clogged air cleaner restricts the engine’s
air intake, increasing fuel consumption,
reducing engine power, and
causing spark plug fouling.
This motorcycle’s air cleaner element
consists of a wet paper filter, which cannot
be cleaned.
The air cleaner element must be replaced
in acco ...