Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionBalance Adjustment
If the wheel always stops in one position, provisionally
attach a balance weight [A] on the rim at the marking using
adhesive tape.
Rotate the wheel 1/4 turn [B], and see whether or not the
wheel stops in this position. If it does, the correct balance
weight is being used.
If the whe ...
Check 3-6: Neutral Indicator Light (LED) Inspection
Connect the leads in the same circuit as Check 3-2.
Connect the terminal [8] to the battery (–) terminal.
Check that the neutral indicator light (LED) [A] goes on.
If the indicator light does not go on, replace the meter unit.
...
Valve Clearance
Valve and valve seat wear decreases
valve clearance, upsetting valve timing.
NOTICE
If valve clearance is left unadjusted,
wear will eventually
cause the valves to remain
partly open; which lowers performance,
burns the valves and
valve seats, and may cause serious
engine damage.
Valve cle ...