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 InspectionPiston Ring Groove Width Inspection
Measure the piston ring groove width.
Use a vernier caliper at several points around the piston.
Piston Ring Groove Width
Standard:
Top [A] 0.82 0.84 mm (0.0323
0.0331 in.)
Second [B] 0.82 0.84 mm
(0.0323 0.0331 in.)
Service Limit:
0.92 mm (0.036 in.)
Second 0.92 mm (0.036 in.)
...
CAN Communication (Transmission)/CAN Bus OFF Monitor Inspection (Service Code
b 57) CAN Communication (Reception) Monitor Inspection (Service Code b 58)
Remove:
Seat (see Seat Removal in the Frame chapter)
Immobilizer (Equipped Models)/Kawasaki Diagnostic
System Connector Cap [A]
Measure the CAN communication line resistance.
Immobilizer (Equipped Models)/Kawasaki Diagnostic
System Connector [A]
GY/BL Terminal [B]
LB Ter ...
Main Throttle Sensor Output Voltage Inspection
Measure the output voltage at the main throttle sensor in
the same way as input voltage inspection, note the following.
Disconnect the main throttle sensor connector and connect
the setting adapter [A] between these connectors.
Special Tool - Throttle Sensor Setting Adapter: 57001
-15 ...