Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionAir Switching Valve Installation
Install the air switching valve [A] with hose [B] as shown
in the figure.
Front [C]
Left Side View [D]
White Paint [E]
Air Switching Valve Operation Test
Refer to the Air Suction System Damage Inspection in the
Periodic Maintenance chapter.
Air Switching Valve Unit Test ...
Charging Voltage Inspection
Check the battery condition (see Charging Condition Inspection).
Warm up the engine to obtain actual alternator operating
conditions.
Remove the front seat (see Front Seat Removal in the
Frame chapter).
Check that the ignition switch is turned off, and connect
the hand tester [A] to t ...
Oil Pressure Switch Installation
Using a high flash-point solvent, clean off any oil or dirt
that may be on the silicone sealant coating area. Dry
them with a clean cloth.
Apply silicone sealant to the threads of the oil pressure
switch, and tighten it.
Sealant - Liquid Gasket, TB1211: 56019-120
Torque - Oil Pressure ...