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 InspectionCompression Damping Force Adjustment
To adjust the compression damping force, turn the compression
damping adjuster [A].
The standard adjuster setting is the 4 1/2 turns out from
the fully clockwise position.
WARNINGIf both adjusters are not adjusted
equally, handling
may be impaired and a hazardous condition ma ...
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 ...
Valve Seat Inspection
Remove the valve (see Valve Removal).
Check the valve seating surface [A] between the valve [B]
and valve seat [C].
Measure the outside diameter [D] of the seating pattern
on the valve seat.
If the outside diameter is too large or too small, repair the
seat (see Valve Seat Repair).
Val ...