Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionFuel Injector Output Voltage Inspection
NOTE
Be sure the battery is fully charged.
Turn the ignition switch to OFF.
Remove the ECU (see ECU Removal).
Do not disconnect the ECU connector
Connect a digital meter [A] to the connector (gray) [B] with
the needle adapter set.
Special Tool - Needle Adapter Set: 57001-1457
...
Maintenance and adjustment
The maintenance and adjustments outlined in this chapter must be carried
out in
accordance with the Periodic Maintenance Chart to keep the motorcycle in good
running condition. The initial maintenance is vitally important and must not be
neglected.
With a basic knowledge of mechanics and the ...
Battery Maintenance
It is the owner’s responsibility to keep
the battery fully charged. Failure to do
so can lead to battery failure and leave
you stranded.
If you are riding your vehicle infrequently,
inspect the battery voltage
weekly using a voltmeter. If it drops
below 12.8 volts, the battery should be
...