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 InspectionSeat Cover Removal
Remove:
Rear Seat (see Rear Seat Removal)
Remove the bolts [A].
Remove the upper seat cover backward [B] to clear the
hook portions.
Remove:
Front Seat (see Front Seat Removal)
Quick Rivets [A]
Bolts [B]
Seat Covers [C]
...
Bolts, Nuts and Fasteners Tightness Inspection
Check the tightness of the bolts and nuts listed here. Also,
check to see that each cotter pin is in place and in good
condition.
NOTE
For the engine fasteners, check the tightness of them
when the engine is cold (at room temperature).
If there are loose fasteners, retighten them to ...
Lower Crankcase Assembly
Install the ball bearing [A] and the oil level inspection window
[B] until they are bottomed
Apply soap and water solution to the oil level inspection
window before installation.
Install the new circlip [C].
Apply a non-permanent locking agent to the oil passage
plug [D].
Tighten: ...