Slow Speed System; Choke And Fresh Air System - Club Car TURF 272 Maintenance Manual

FUEL SYSTEM
If the engine exhibits symptoms of overly rich or lean fuel mix after all maintenance and adjustments are cor-
rectly performed, the main jet should be replaced. A smaller numbered jet gives a leaner mixture and a larger
numbered jet gives a richer mixture. It is recommended that any change be limited to one jet size difference
from the standard jet.
STANDARD JETTING
Pilot air screw
Pilot jet
Main jet
Throttle valve stop screw
FUEL TANK
AIR CLEANER
FLOAT MAIN AIR
CHAMBER PASSAGE
MAIN JET BLEED PIPE
Figure 14-1 Fuel Flow Sequence

SLOW SPEED SYSTEM

The slow speed system supplies fuel during low speed running. Low speed running without load requires very
low intake airflow. The throttle valve (Figure 14-3, Page 14-4) is almost closed when this is the case, and as
high negative pressure is created on the back side of the throttle valve, intake air is drawn in and metered
through the pilot air jet. The intake air draws fuel, metered by the pilot jet (Figure 14-3, Page 14-4), from the
carburetor float chamber. The combustible mixture of air and fuel is then delivered into the venturi through the
pilot outlet and bypass. When the engine is operating at low speed, fuel is supplied mainly through the pilot
outlet (Figure 14-3, Page 14-4).
The air/fuel mixture is adjusted by the pilot screw (needle valve) (Figure 14-3, Page 14-4).

CHOKE AND FRESH AIR SYSTEM

The choke system aids in starting the engine in cold weather. When starting a cold engine, the choke cable
handle (1) (Figure 14-4, Page 14-5) is pulled. This restricts the air flow to the venturi, causing a very high vac-
uum that draws fuel into the venturi at a high rate and thus creates a "fuel rich" mixture. The choke handle is
pulled until the engine starts, and then released when the engine begins to run smoothly.
An air duct provides the engine with clean, cool air from outside the engine compartment. This feature
increases engine horsepower and greatly extends air filter life.
2001/2002 Turf/Carryall 272 Gasoline Vehicle Maintenance and Service Manual
FE350 ENGINE FE400 ENGINE
Middle of Travel
40 (x1/100) 45 (x1/100)
85 (x1/100) 88 (x1/100)
1200-1250 RPM
ENGINE
CARBURETOR
BORE
MAIN
NOZZLE
VENTURI
INTAKE
AIR
CARBURETOR
FUEL
AIR
AIR / FUEL MIXTURE
Figure 14-2 Air/Fuel Mixture
How the Carburetor Works
INTAKE STROKE
OF PISTON
Page 14-3
14