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 InspectionSpring Plate Free Play Measurement
Insufficient clutch free play will cause the engine braking
effect to be more sudden, resulting in rear wheel hop. On
the other hand, if the free play is excessive, the clutch lever
may feel “spongy� or pulsate when pulled.
Hold an extra drive shaft in a vise and install the following
c ...
External Shift Mechanism Inspection
Examine the shift shaft [A] for any damage.
If the shaft is bent, straighten or replace it.
If the serration [B] are damaged, replace the shaft.
If the spring [C] is damaged in any way, replace it.
If the shift mechanism arm [D] is damaged in any way,
replace the shaft.
Check the s ...
Crankshaft Sensor Peak Voltage Inspection
NOTE
Be sure the battery is fully charged.
Using the peak voltage adapter [A] is more reliable way
to determine the condition of the crankshaft sensor than
crankshaft sensor internal resistance measurements.
Disconnect the crankshaft sensor lead connector (see
Crankshaft Sensor ...