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 InspectionCrankshaft Sensor Removal
Remove:
Fuel Tank (see Fuel Tank Removal in the Fuel System
(DFI) chapter)
Crankshaft Sensor Lead Connector [A]
Remove:
Right Lower Fairing (see Lower Fairing Removal in the
Frame chapter)
Bolts [A]
Crankshaft Sensor Cover [B] and Gasket
Oil Pressure Switch Terminal [C]
...
Fuel Filter Cleaning
The fuel filter [A] is built into the fuel pump and can not be
cleaned or checked.
If the fuel filter is suspected of clogging or being damaged,
replace it with the fuel pump as a set.
Fuel Pump Circuit
1. Ignition Switch
2. Engine Stop Switch
3. Joint Connector E
4. ECU
5. Engine G ...
Lower Fairing Removal
Remove the quick rivets [A].
Remove:
Quick Rivets [A]
Bolts [B]
Pull up the core by the flat-head screwdriver (–), and then
remove the quick rivet.
Clear the hook portions on the upper edges [C] from the
slots, and remove the left lower fairing [D].
While pulling down ...