If they appear damaged or deteriorated, replace them.

Balancer Adjustment
Torque LimiterSubthrottle Sensor Resistance Inspection
Turn the ignition switch to OFF.
Disconnect the subthrottle sensor connector.
Connect a digital meter [A] to the subthrottle sensor connector
[B].
Measure the subthrottle sensor resistance.
Subthrottle Sensor Resistance
Connections: BL lead [D] ←→ BR/BK lead [C]
Standard: ...
Swingarm Installation
Visually inspect the chain guide [A].
Replace the chain guide if it shows any signs of abnormal
wear or damage.
Apply a non-permanent locking agent to the threads of
the chain guide bolt [B].
Apply plenty of grease to the lip of the oil seals [A].
Be sure to install the oil seals ...
Before Servicing
Before starting to perform an inspection service or carry out a disassembly
and reassembly operation
on a motorcycle, read the precautions given below. To facilitate actual
operations, notes, illustrations,
photographs, cautions, and detailed descriptions have been included in each
chapter w ...