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 DiscSeparator Operation Test
WARNINGGasoline is extremely flammable and can be
explosive
under certain conditions. Turn the ignition
switch OFF. Do not smoke. Make sure the area is
well-ventilated and free from any source of flame
or sparks; this includes any appliance with a pilot
light.
...
Exhaust Butterfly Valve Actuator Resistance Inspection
Turn the ignition switch to OFF.
Disconnect the exhaust butterfly valve actuator lead connector
(2 pins connector) [A].
Set the hand tester to the × 1 Ω range and connect it to
the exhaust butterfly valve actuator connector.
Special Tool - Hand Tester: 57001-1394
Measure ...
KIBS Equipped Models
1. Clutch Cable
2. Vacuum Hose (Equipped Models)
3. Left Switch Housing Lead
4. Main Harness
5. Front Brake Hose
6. Throttle Cables
7. Right Switch Housing Lead
8. Bracket (Hold the brake pipes.)
9. Run the meter lead to outside of the meter bracket.
10. Run the vacuum hoses to inside o ...