Jeep UNIVERSAL CJ-2A - Page 99

F
FUEL SYSTEM
"C", Fig. 120, to fully close the throttle. To mea-
sure the stroke, place the gauge on top of the bowl
cover, Fig. 121, open the throttle wide and measure
to the top of the pump plunger rod. Close the throt-
tle tight and measure again. The difference, which
is the pump stroke, should be 1?.(
4
" [6,747 mm.].
To adjust the stroke bend the throttle connector
rod at "A". IMPORTANT: Always set the pump
stroke before setting the metering rod. If set after-
wards the metering rod will be thrown out of ad-
justment.
If the throttle connector rod and throttle shaft arm
assembly are worn, it will allow the throttle valve
to be opened by the accelerator pedal before the
pump jet begins to discharge fuel, resulting in a
flat
spot. Replace all worn parts because the opera-
tion of the metering rod is also affected.
F-13. Choke Circuit
The choke connector link connects the choke and
throttle levers and opens the throttle slightly when
the choke valve is closed, thus insuring quick
starting and freedom from stalling during the
warm up period.
F-14. Carburetor
• Models CJ-3B, C]-5, C]-6, D]-3A
Current production models CJ-3B, C]-5, and CJ-6
have a Carter YF -938SD carburetor superseding
the earlier YF -938SC, YF -938SA, or YF -938S
models.
Note: Conversion kits for changing earlier models
to SD models are available. See Par. F-27. It is
recommended that when a carburetor is converted
that a tag be fashioned st:il.mped with the new
model number and installed under one of the air
horn screws. Look for such a tag to determine if
the carburetor has previously been converted.
The carburetor for model DJ-3A is a Carter model
YF-2392S. Carburetors listed above are all in the
same YF series and have only minor differences.
Descriptions and repair procedures given in the
following paragraphs apply equally to all YF -series
carburetors. YF -series carburetors employ manual
and vacuum control of the metering rod and
accelerator pump.
The carburetor controls and vaporizes the fuel
through five separate circuits: float circuit, low-
speed circuit, high-speed circuit, choke circuit, and
accelerating-pump circuit. A description of the
function and operation of each circuit provides an
over all description of the carburetor.
For identification, the series designation is stamped
on the body under the name Carter and the model
designation is stamped on a flange protruding
from the body.
Note: When checking for carburetor icing causes,
also
check the vacuum-pump-to-manifold vacuum
line connector.
F-15. Float Circuit
The float circuit, Fig. 122, consists of a float,
float
pin, air horn gasket and the needle and seat
assembly. These parts control the fuel level in the
carburetor bowl, a supply being maintained for all
circuits under all operating conditions. To prevent
98
float
vibration from affecting the fuel level, the
inlet or float valve is spring loaded. Should the
needle and seat become worn, they must be re-
placed with a matched set, including the spring,
which is the only way they are supplied. When
reinstalling the float, be sure to install the float pin
with the stop shoulder on the side away from the
bore of the carburetor.
F-16. Float Adjustment
Correct float level setting is required for accurate
metering of fuel in both low- and high-speed jets.
To set the float, remove and invert the bowl cover.
Remove the bowl cover gasket. Allow the weight
of the float to rest on the needle and spring. Be
sure there is no compression of the spring other
than the weight of the float. Adjust the level by
bending the float arm lip that contacts the needle
(not the arm) to provide specified clearance be-
tween the float and cover.