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 InspectionGear 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]
...
Fuel Injector Audible Inspection
NOTE
Be sure the battery is fully charged.
The secondary fuel injectors are operating with following
conditions.
1. The engine speed is more than 6 000 r/min (rpm).
2. The throttle opening is more than 12В°.
Remove:
Fuel Tank (see Fuel Tank Removal)
Primary Fuel Hose (see Fuel ...
Refreshing Charge
Remove the battery (see Battery Removal).
Do refresh charge by following method according to the
battery terminal voltage.
WARNINGThis battery is sealed type. Charge with
current and
time as stated below.
Terminal Voltage: 12.0 12.7
V
Standard Charge (see following ...