If they appear damaged or deteriorated, replace them.

Balancer Adjustment
Torque LimiterOxygen Sensor Removal (Equipped Models)
Remove:
Fuel Tank (see Fuel Tank Removal in the Fuel System
(DFI) chapter)
Right Lower Fairing (see Lower Fairing Removal in the
Frame chapter)
Disconnect the oxygen sensor lead connector [A].
NOTICE
Do not pull strongly, twist, or bend the oxygen sensor
lead. This may cause the wi ...
Special Tools
Fork Oil Level Gauge:
57001-1290
Vacuum Gauge:
57001-1369
Hand Tester:
57001-1394
Throttle Sensor Setting Adapter #1:
57001-1400
Peak Voltage Adapter:
57001-1415
Needle Adapter Set:
57001-1457
Throttle Sensor Setting Adapter:
57001-1538
Measuring Adapter:
57001-1700
...
Spark Plug Condition Inspection
Remove the spark plugs (see Spark Plug Replacement in
the Periodic Maintenance chapter).
Visually inspect the spark plugs.
If the spark plug center electrode [A] and/or side electrode
[B] are corroded or damaged, or if the insulator [C]
is cracked, replace the plug.
If the spark plug is ...