If they appear damaged or deteriorated, replace them.

Balancer Adjustment
Torque LimiterSteering Stem Bearing Lubrication
Remove the steering stem (see Stem, Stem Bearing Removal
in the Steering chapter).
Using a high flash-point solvent, wash the upper and
lower ball bearings [A] in the cages.
Wipe the upper and lower outer races which are press
-fitted into the head pipe to clean off grease and dirt.
V ...
Lubrication
Lubrication is necessary after riding
through rain or on wet roads, or any
time that the chain appears dry.
Use a lubricant for sealed chains to
prevent deterioration of chain seals. If
the chain is especially dirty, clean it
using a cleaner for sealed chains following
the instructions suppli ...
Drive Chain Removal/Installation
NOTE
Since the drive chain is installed through the swingarm,
The chain can not be removed other than by cutting it.
Prepare the new link pin, link plate, grease seals, and
tools for rejoining the chain.
Remove:
Bolts [A]
Front Footpeg Bracket [B]
Remove:
Bolts [A]
Chain Cover [B]
...