Replace it if necessary.

Inner Tube Inspection
Spring Tension InspectionParts Removal/Installation
WARNINGGasoline is extremely flammable and can be
explosive
under certain conditions. Turn the ignition
switch OFF. Do not smoke. Make sure the area is
well-ventilated and free from any source of flame
or sparks; this includes any appliance with a pilot
light.
NOTICE
...
Rider’s Seat Removal
Remove the bolts and seat cover.
A. Bolts
B. Seat Cover
Remove the mounting bolts and pull
off the seat upward.
A. Mounting Bolts
B. Rider’s Seat ...
Fuel Tank and Cap Inspection
Visually inspect the gasket [A] on the tank cap for any
damage.
Replace the gasket if it is damaged.
Check to see if the water drain pipe [B] and fuel breather
pipe [C] in the tank are not clogged. Check the tank cap
breather also.
If they are clogged, remove the tank and drain it ...