If the disc has worn past the service limit, replace it.
Measuring Area [B]

Brake Disc Thickness Standard:
Front 5.3
5.7 mm (0.21
0.22 in.)
Rear 4.8
5.2 mm (0.19
0.20 in.)
Service Limit:
Front 5.0 mm (0.20 in.)
Rear 4.5 mm (0.18 in.)
Brake Disc Installation
Brake Disc Warp InspectionFuel Flow Rate Inspection
WARNINGGasoline is extremely flammable and can be
explosive
under certain conditions, creating the
potential for serious burns. Make sure the area is
well-ventilated and free from any source of flame
or sparks; this includes any appliance with a pilot
light. Do not smoke. T ...
Drive Chain Wear Inspection
Remove the chain cover (see Drive Chain Removal/Installation
in the Final Drive chapter).
Rotate the rear wheel to inspect the drive chain for damaged
rollers, and loose pins and links
If there is any irregularity, replace the drive chain.
Lubricate the drive chain if it appears dry.
...
Piston Ring Thickness Inspection
Measure the piston ring thickness.
Use the micrometer to measure at several points around
the ring.
Piston Ring Thickness
Standard:
Top [A] 0.77 0.79 mm (0.0303
0.0311 in.)
Second [B] 0.78 0.79 mm
(0.0307 0.0311 in.)
Service Limit:
Top 0.70 mm (0.0276 in.)
Second 0.71 mm (0.0280 ...