Engine Cranks But Won't Start; Lean Mixture; Rich Mixture; Backfiring Or Misfiring During Acceleration - Honda TRX400EX FOURTRAX 1999 Service Manual

FUEL SYSTEM
SPECIFICATIONS
Carburetor identification number
Main jet
Slow jet
Jet needle clip position
Pilot screw opening
Float level
Throttle lever free Dlav
TOOL
Carburetor float level gauge

Pilot screw wrench

TROUBLESHOOTING

Engine cranks but won't start

No fuel in tank
No fuel to carburetor
-Clogged fuel stainer
-Clogged fuel line
-Clogged fuel tank breather tube
Too much fuel getting to the engine
-Clogged air cleaner
-Flooded carburetor
Intake air leak
Improper choke operation
Improper throttle operation
No
spark at plug (faulty ignition system

Lean mixture

Clogged fuel jets
Faulty float valve
Float level too low
Restricted fuel line
Clogged carburetor air vent tube
Restricted fuel tank breather tube
Intake air leak
Faulty throttle valve

Rich mixture

Starting enrichment valve close
Clogged air jets
Faulty float valve
Float level too high
Dirty air cleaner
Worn jet needle or needle jet
5-2
ITEM
07401 0010000
-
07908-4220201
section 16)
SPECIFICATIONS
#38
3rd groove from top
See page 5-13
18.5 mm (0.73
1,400
-
3 8 mm
Engine stalls, hard t o start, rough idling
Restricted fuel line
Fuel mixture too leanlrich
Contaminated/ deteriorated fuel
Intake air leak
Misadjusted idle speed
Misadjusted pilot screw
Restricted fuel tank breather tube
Clogged air cleaner
Clogged slow circuit
Starting enrichment valve close (ON)
Faulty ignition system (section
Afterburn when engine braking is used
Lean mixture in slow circuit
Faulty air cut-off valve
Faulty ignition system (section

Backfiring or misfiring during acceleration

Lean mixture
Faulty ignition system (section
Poor performance (driveability) and poor fuel economy
Clogged fuel system
Faulty ignition system (section 16)
in)
-
5/16 in)
16)
16)