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 InspectionOverview
S-KTRC is a highly sophisticated system based on MotoGP racing technology.
Unlike the KTRC
system used on the GTR1400 ABS (Concours 14 ABS in N. America), which is
designed to offer rider
reassurance when traversing slippery surfaces, S-KTRC, is designed to maximize
forward motion,
allowing ...
Torque and Locking Agent
The following tables list the tightening torque for the major fasteners
requiring use of a
non-permanent locking agent or silicone sealant etc.
Letters used in the “Remarks” column mean:
AL: Tighten the two clamp bolts alternately two times to ensure even tightening
torque.
G: Apply ...
Air Switching Valve
Air Switching Valve Operation Test
Refer to the Air Suction System Damage Inspection in the
Periodic Maintenance chapter.
Air Switching Valve Unit Test
Remove the air switching valve (see Air Switching Valve
Removal in the Engine Top End chapter).
Set the hand tester [A] to the × 1 ...