If they appear damaged or deteriorated, replace them.

Balancer Adjustment
Torque LimiterTorque 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 ...
Lights and Switches Operation Inspection
First Step
Set the gear position in the neutral position.
Turn the ignition switch to ON.
The following lights should go on according to below table.
If the following light does not go on, inspect the meter
unit (see Meter Unit Inspection in the Electrical System
chapter).
...
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 ...