TROUBLE SHOOTING
OPERATING ERRATICALLY
a.
Clogged fuel line.
HARD STARTING OR LOSS OF
a.
Faulty ignition.
1.
Leads grounded or loose.
2.
Breaker points faulty or
improperly gapped.
3.
Spark plug faulty or improp
b. Water in fuel.
c.
Vent in gas cap plugged.
d. Faulty fuel pump.
e. Gasket leaking (carb.-manifold)
f.
Governor improperly set.
g.
Carburetor improperly adjusted.
KNOCKING
defective. a.
Fuel octane too low.
b.
Ignition timing wrong
erly gapped.
4.
Coil or condenser
b.
Faulty carburetion.
1.
Fuel line clogged (dirt-gum)
2.
Fuel pump faulty.
3.
Carburetor dirty or improp
erly adjusted.
c. Poor compression.
1.
Head loose or gasket leak
ing.
2.
Valves stickinq or leaking.
3.
Piston rings worn.
CARBURETOR ADJUSTMENT
c. Carbon build-up in combustion
chamber.
d. Engine overheated.
OCCASIONAL "SKIP" AT
SPEED
a. Spark plug fouled, faulty or gap
too wide.
b.
Ignition timing wrong
c. Carburetor improperly adjusted.
OVERHEATING
�.
Air intake screen or fins
.
clogged.
b.
Oil level too high (or low).
c.
Fuel mixture too lean
d. Ignition timing wrong
e. Engine overloaded.
f.
Tappet clearance too close.
IDLES POORLY
a. Idle Speed too low.
b.
Idle Fuel improperly adjusted.
c.
Gasket leaking (carb.-manifold)
d.
Spark plug gap too close.
BACKF I RING
a.
Carburetor set too lean (Main
Fuel).
b.
Breaker points improperly gapped
(timing).
c. Valve sticking.
Lack of power and black sooty exhaust smoke usually indicates that fuel mixture is too rich. An
"overrich" mixture may also be caused by a clogged air cleaner--check this before readjusting car
buretor.
Fuel mixture may be too lean if engine "skips" or backfires at high speed.
Main Fuel Adjustment: For preliminary setting. turn MAIN FUEL screw in clockwise direction until it
bottoms lightly
not force) then back out
2
turns. With engine thoroughly warmed up and running at
full throttle and full load; turn MAIN FUEL screw in until engine slows down (lean setting) then turn
screw out until engine regains speed and then starts to slow down (overrich setting), Turn screw back
in until it is positioned halfway between lean al1d overrich settings--when properly adjusted engine will
accelerate smoothly and operate with steady governor action.
Idle
Rough idle is usually caused by the idle speed being set too low.
Turn IDLE SPEED
screw in
direction) to increase speed. Ii engine still idles poorly after speed is increased,
stop engine and turn IDLE FUEL screw all the way in (clockwise) until it bottoms lightly (do not force
screw), then back out
1-1/4
turns. Restart engine and check idle--turn needle in or out
(1/4
turn at a
time) until smoothest idle is achieved.
IDLE FUEL
ADJUSTMENT
ADJUSTMENTS - SIDE DRAFT CARBURETOR
4
MAIN FUEL
ADJUSTMENT
ADJUSTMENTS - UPDRAFT CARBURETOR
