Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionWindshield and Other Plastic Parts
After washing use a soft cloth to
gently dry plastic parts. When dry,
treat the windshield, headlight lens,
and other nonpainted plastic parts with
an approved plastic cleaner/polisher
product.
NOTICE
Plastic parts may deteriorate
and break if they come in contact
with chemical substances
...
Oxygen Sensor Heater Resistance Inspection
Turn the ignition switch to OFF.
Remove the fuel tank (see Fuel Tank Removal in the Fuel
System (DFI) chapter).
Disconnect the oxygen sensor lead connector [A].
Connect a digital meter [A] to the terminals in the oxygen
sensor lead connector [B].
Measure the oxygen sensor heat ...
Inquiries to Rider
Each rider reacts to problems in different ways, so it is important to
confirm what kind of condition
the rider is dissatisfied with.
Try to find out exactly what problem occurs under exactly what
conditions by asking the rider; knowing
this information may help you reproduce the prob ...