Jeep UNIVERSAL CJ-2A - Page 103

F
FUEL SYSTEM
i. Remove metering rod jet. Remove low-speed
jet.
Note: Do not remove pressed-in parts such as
nozzle, pump jet, or antipercolator air bleed.
j. Remove body flange attaching screws, body
flange assembly, and gasket.
k. Remove idle-adjustment screw, spring, idle
port· rivet, throttle lever assembly, washer, fast
idle arm, throttle plate screws, throttle plate, and
throttle shaft.
I. Remove throttle shaft seal by prying out seal
retainer.
Note: Do not remove pressed-in vacuum passage
orifice.
m. Remove c):wke valve screws and choke valve.
Unhook choke spring and slide shaft from housing.
n. Wash all parts in carburetor cleaning solutior,
and blow out passages with compressed air. Do not
immerse diaphragm or seals in cleaning solution.
Inspect all parts for wear or damage. Always use
new
gaskets when reassembling.
F-26. Carburetor Assembly
To expedite reassembly, it is advisable to group all
related parts by the circuit to which they belong.
a. Install throttle shaft seal and retainer in flange
casting.
b. Install fast-idle arm, washer, and lever assembly
on throttle shaft. Slide shaft into place and install
throttle valve.
c. Install idle port rivet plug and idle adjusting
screw and spring.
d. Attach flange assembly to body casting. Use
new gasket.
e. Install lqw:-speed jet assembly.
, .. "!!.~
f. Install pump intake strainer in pump diaphragm
housing and carefully press into recess.
Note: If strainer is even slightly damaged, a new
one must be installed.
g. Install pump diaphragm assembly in diaphragm
housing. Then, install pump diaphragm spring
(lower) and retainer.
h. Install pump lifter link, metering rod arm, upper
puinp spring, and retainer.
i. Install metering rod jet.
Note: No gasket is used with this jet.
j. Install diaphragm housing attaching screws in
the diaphragm housing, making sure that the
edges of the diaphragm are not wrinkled. Lower
into place and tighten screws evenly and securely.
k. Install throttle shaft seal, dust seal washer, and
shaft seal spring.
102
I. Install pump connector link in the throttle arm
assembly. Install throttle shaft arm assembly on
throttle shaft guiding connector link in pump lifter
link hole.
CAUTION: Linkage must not bind in any throttle
position. If binding occurs, loosen clamp screw in
throttle arm, adjust slightly, then retighten screw.
m. Install pump check disc, disc retainer, and lock
ring.
n. Install metering rod and pin spring. Connect
metering rod spring.
o. Check and if necessary correct metering rod
adjustment. Follow procedure of Par. F -20.
p. Install needle seat and gasket assembly, needle,
float and float pin. The stop shoulder on the float
pin must be on the side away from the bore of
the carburetor.
q. Set float level to specifications. Follow pro-
cedure of Par. F-16.
r. Install air horn gasket and air horn assembly.
Install attaching screws, lock washers, and choke
tube clamp assembly. Tighten center screws first.
s. Slide choke shaft and lever assembly into place
and connect choke lever spring. Install choke valve.
Center the valve by tapping lightly, then hold in
place with fingers when tightening screws.
t. Install fast-idle connector rod with offset portion
of rod. on top and pin spring on outside. Install
fast-idle connecting rod spring.
F -27. Correcting Acceleration Flat Spot
• Models CJ-3B, CJ-5, CJ-6
Using Carburetor Models 938-S, 938-SA, 938-SC
Inasmuch as a flat spot on acceleration or low speed
stumble can come from causes other than car-
buretor malfunction, it is recommended that engine
tuning be thoroughly checked before attempting
any actual carburetor work. Make sure that
ignition, compression, and timing are correct and
that fuel pump is supplying enough gas. Also,
the F -head engine employs a water-heated intake
manifold. Proper vaporization of the fuel depends
on correct intake manifold temperature. Since this
temperature is controlled by the cooling system
thermostat, include an operational check of the
thermostat when diagnosing the stumble. Operating
temperatures consistently below 155°F. can cause
stumble.
If the stumble persists, a YF -938-S, YF -938-SA,
or YF -938-SC carburetor can be converted to a
YF -938-SD carburetor by installing Special Kit
924161, consisting of a pump discharge check
needle, a metering rod, and a metering rod jet. If
this kit is installed, the pump discharge check
needle replaces the original ball, weight, and re-
tainer and the small wire-type retainer used with
the ball check assembly must not be reinstalled.