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 DiscEngine Oil Flow Chart
1. Oil Screen
2. Oil Pump
3. Oil Pressure Relief Valve
4. Oil Filter
5. Oil Pipe
6. Oil Cooler
7. Balancer Oil Passage
8. Main Oil Passage
9. Crankshaft Oil Passage
10. Oil Pressure Switch
11. Camshaft Oil Passages
12. Drive Shaft Oil Passage
13. Output Shaft Oil Passage
14. Starter ...
Tachometer
The tachometer shows the engine
speed in revolutions per minute (r/min,
rpm).
On the right side of the tachometer
face is a portion called the “red zone�.
Engine r/min (rpm) in the red zone is
above maximum recommended engine
speed and is also above the range for
good performance.
...
Special Tools
Fork Oil Level Gauge:
57001-1290
Vacuum Gauge:
57001-1369
Hand Tester:
57001-1394
Throttle Sensor Setting Adapter #1:
57001-1400
Peak Voltage Adapter:
57001-1415
Needle Adapter Set:
57001-1457
Throttle Sensor Setting Adapter:
57001-1538
Measuring Adapter:
57001-1700
...