Honda TRX420FPA Owner's Manual page 197

If Your Engine Quits or Won't Start
SYMPTOM: Engine starts, but runs poorly.
POSSIBLE CAUSE
high coolant
temperature
runs erratically,
misfires
blubbers (rich fuel
mixture)
sooty exhaust (rich
fuel mixture)
detonates or pings
under load
afterfires (backfires)
pre-ignition (runs on
after ignition
switched OFF)
SYMPTOM: Engine starts, but runs poorly or dies when hot.
POSSIBLE CAUSE
poor or inadequate
fuel flow due to
clogged fuel filter
188 Taking Care of the Unexpected
WHAT TO DO
Check the high coolant temperature
indicator. Refer to If the High
Coolant T emperature Indicator
Lights, page 198 .
See your Honda dealer.
See your Honda dealer.
See your Honda dealer.
If applicable, switch to the
recommended octane gasoline
(page 108 ) or change your brand of
gasoline. If the problem persists, see
your Honda dealer.
See your Honda dealer.
See your Honda dealer.
WHAT TO DO
See your Honda dealer.
(ensure clean fuel supply)