If any is worn down to the service limit, replace the brush assy.
Starter Motor Brush Length [B] Standard: 12.05 mm (0.4744 in.) Service Limit: 6.55 mm (0.258 in.)

Starter Motor Assembly
Commutator Cleaning and InspectionFront Fork Removal (Each Fork Leg)
Loosen the front fork top plug [A] beforehand if the fork
leg is to be disassembled.
Special Tool - Top Plug Wrench (45 mm) [B]: 57001-1741
NOTE
Loosen the top plug after loosening the handlebar
clamp bolt [C] and upper front fork clamp bolt [D].
Remove:
Upper Fairing Assembly (see Up ...
Connecting Rod Big End
Bearing Insert/Crankpin Wear Inspection
Remove the connecting rod big end (see Connecting Rod
Removal).
Cut strips of plastigage to crankpin width. Place a strip
on the crankpin parallel to the crankshaft installed in the
correct position.
Tighten the connecting rod big end nuts to the specified
torque (see Connecting Rod I ...
Gear Position Switch Removal
Remove:
Oil Pump (see Oil pump Removal in the Engine Lubrication
System chapter)
Engine Sprocket (see Engine Sprocket Removal in the
Final Drive chapter)
Fuel Tank (see Fuel Tank Removal in the Fuel System
(DFI) chapter)
Disconnect the connector [A].
Remove:
Screws [A]
...