Honda TRX400X 2009 Owner's Manual page 182

If Your Engine Quits or Won't Start
SYMPTOM:
POSSIBLE CAUSE
idles roughly, too
fast, stalls
poor engine
performance at
altitudes above
3,000 feet.
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)
Taking Care of the Unexpected
174
Engine starts, but runs poorly.
Check engine idle adjustment
(page
see your Honda dealer.
Ask your Honda dealer to modify the
carburetion with a high altitude jet.
Refer to
Adjustment,
See your Honda dealer.
See your Honda dealer.
See your Honda dealer.
If applicable, switch to the
recommended octane gasoline
(page
gasoline. If the problem persists, see
your Honda dealer.
See your Honda dealer.
See your Honda dealer.
WHAT TO DO
112 ). If the problem persists,
High Altitude Carburetor
page 193
89 ) or change your brand of
.