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FUELSVSTEM
TROUBLESHOOTING
Engine cranks
but
won't
sta
rt
•
No fuel in lank
•
No fuel to carburetor
-
Clogged fuel strainer
-
Clogged fuellins
-
Clogged
fuel tank breather hose
-
Misadjusted fuel level
•
Too
much fuel getting to the engine
- Clogged ai
r
cleaner
-
flooded
ca
rburet
or
•
Intake air leak
•
Contaminated/deteriorated fuel
-
Clogged jets
•
Clogged
starting
enrichment (SE) valve circuit
•
Improper
choke
operation
•
Improper throttle operation
•
No
spark at
plug (faulty
ignition system
-
(page 20-4))
Lean
mixture
•
Clogged
fuel jets
•
Faulty float
valve
•
Float level too low
•
Restricted fuel
line
•
Clogged
carburetor
air
vent
hose
•
Restricted
fuel tank breather
hose
•
Intake air leak
•
Faulty vacuum piston
•
Faulty throttle
valve
Rich
mixture
•
SE valve open
(ON)
•
Clogged air jets
•
Faulty
float valve
•
Float
level
too high
•
Dirty
air deaner
•
Clogged slow circuit
•
Clogged SE valve
circuit
•
Worn jet needle or needle
jet
•
Faulty
vacuum piston
Engine stalls,
hard to
start,
rough idling
•
Restricted
fuel
line
•
Fuel mixture too
lean/rich
•
Contaminated/deteriorated fuel
-
Clogged
jets
•
Intake air
leak
•
Misadjusted idle
speed
•
Restricted fuel tank breather
hose
•
Dirty air deaner
•
Misadjusted pilot screw
•
Faulty
ignition
system
(page
20-4)
Afterburn
when engine
braki
ng
is
used
•
Lean mixtu re in slow
circui
t
•
Faulty
ignition
system
(page
20-4)
Backfiring
or
misfiring
during
acceleration
•
Lean mixtu re
•
Faulty
ignition system (page
20-4)
Poor
performance (drive-ability) and
poor fuel
economy
•
Clogged
fuel
system
•
Faulty
ignition system (page
20-4)
5-4
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