If they appear damaged or deteriorated, replace them.

Balancer Adjustment
Torque LimiterLights 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).
...
Cylinder Compression Measurement
NOTE
Use the battery which is fully charged.
Warm up the engine thoroughly.
Stop the engine.
Remove the spark plugs (see Spark Plug Replacement in
the Periodic Maintenance chapter).
Attach the compression gauge [A] and adapter [B] firmly
into the spark plug hole.
Using the startermo ...
Muffler Body Installation
Replace the muffler body gasket [A] with a new one.
Install the muffler body gasket to the premuffler chamber
[B] until it is bottomed so that the chamfer side faces premuffler
chamber.
Install the muffler body clamp [C] as shown in the figure.
Insert the projection [D] into the slot [ ...