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PART 10-5 MOTORCRAFT MODEL 4300 CARBURETTOR
10-59
or jet removal tool to remove the main
and auxiliary valve. seats and
gaskets.
INSTALLATION
1.
Install new gaskets on the valve
seats. Then install the seats in the air horn.
2.
Place the main fuel inlet needle
valve in the valve seat.
3.
Position
the
float
and lever
assembly between the hinge posts and over
the fuel inlet valves, then install the float
pivot
pin.
The pin must
be
inserted from
the pump plunger side for self-retention.
4.
Install the air horn on the main
body.
5.
Adjust-the idle fuel mixture and
engine idle speed.
ACCELERATING PUMP, INLET
BALL CHECK, NEEDLE.VALVE AND
DISCHARGE CHECK VALVE DISC.
REMOVAL
1.
Remove the air hom assembly
from the main body of the carburettor.
2.
Remove
the
accelerator
rod
retainer and rod from the accelerating
pump lever, then remove the lever from
the accelerating pump piston and remove
the pump assembly from the air horn.
3.
Remove the discharge checK valve
retainer with a small hook. Invert the air
horn and allow the check valve disc to fall
into palm of hand.
4.
Remove the accelerating pump
inlet ball check retainer with long-nose
pliers, then use a magnet to lift the ball
check from the pump well.
5.
Pick
the
accelerating
pump
discharge needle from the discharge cavity
.
INSTALLATION
1.
Place the accelerating pump ball
EJ
MAJOR REPAIR OPERATIONS
CARBURmOR REMOVAL
Flooding, stumble on acceleration and
other performance complaints are in many
instances, caused by the presence of dirt,
water or other foreign matter in the
carburetor. To aid in diagnosing the cause
of complaint, the carburetor should
be
carefully
removed
from
the
engine
without removing the fuel from the
bowls.
The contents of the bowls may then be
examined
for
contamination
as
the
carburetor is disassembled.
1. Remove the air cleaner (Page 10-67)
Remove the heater hose from the choke
shield (if so
equipped).
2.
Remove the throttle cable or rod
from the throttle
lever.
Disconnect the
distributor vacuum line, in-line fuel filter
and the choke heat tube at the carburetor.
3.
Disconnect the choke clean air
tube from the air
horn.
4. Remove the carburettor retaining
nuts; then remove the carburettor. Re-
move the carburettor mounting gasket,
spacer (if equipped) and lower gasket,
from the intake
manifold.
INSTALLATION
1. Clean
the
gasket
mounting
surfaces of the spacer and carburettor.
Place the spacer between two new gaskets
and position the spacer and gaskets on the
intake manifold. Position the carburettor
on the spacer and gasket and secure it with
the retaining lockwashers and nuts. To
prevent leakage, distortion or damage to
the carburettor body flange, snug the nuts;
then, alternately tighten each nut in a
criss-cross pattern to the specified torque.
2. Connect the in-line fuel fllter
throttle cable, choke heat tube, and
distributor vacuum line. Position the
heater hose behind the choke shield.
3. Connect the choke clear air tube
to the air horn.
4.
Adjust the engine idle speed, the
idle fuel mixture, anti-stall dashpot (if so
equipped) and the accelerating pump
stroke (if required). Install the air cleaner
(Page 10-67)
DISASSEMBLY
To facilitate working on the car-
burettor, and to prevent damage to the
throttle plates, install carburettor legs on
the
base.
If legs are unavailable, install
four 5/16 x 2 1/2 inch bolts and 8 nuts;
install nuts on the bolts, above and below
the carburetor base.
Use a separate container for the
component
parts
of the various assemblies
to facilitate
cleaning,
inspection, and
assembly.
The
following
is
a
step-by-step
sequence of operations for completely
overhauling
the
carburetor.
However,
certain components of the carburetot may
be
serviced
without
a
complete
disassembly of the entire unit.
AIR HORN
1.
Remove the fuel inlet line from
the fuel filter.
2.
Remove the choke clean air pick
up connecting tube from the air
horn.
3.
Remove the choke control rod
retainer from the automatic choke lever.
Separate the rod from the lever.
check ·in the pump inlet hole of the pump
chamber.
Install the ball check retaining
ring (Fig.
27).
2.
Insert the discharge check valve
disc into the valve
cavity,
and install the
valve retainer flush with the air horn
surface. The cross slot in the retainer is
towards the valve.
3.
Place
the
accelerating
pump
discharge needle into the pump discharge
cavity.
4.
Insert
the
accelerating
pump
piston in the air horn
.
5. Compres$
the pump plunger and
insert accelerating pump arm into plunger
stem.
Line up
holes
in lever and insert pivot
pin through the specified hole in lever and
the air horn casting. Install retainer on
pin.
6.
Install the air horn assembly on
the main body.
4.
Remove the accelerator pump rod
retainer or spring from the pump lever.
Separate the rod from the
lever.
5.
Remove
the
air cleaner anchor
screw and remove the air horn to fuel
bowl retaining
screws.
6.
Lift the air horn off the main
body.
7.
Pull
the
float pivot pin and
remove the float assembly.
8.
Using the proper size screwdriver
or jet removal
tool, remove
the main and
auxiliary
(supplemental)
fuel inlet valve
seats and
gaskets.
9.
Remove the secondary air valve
lever retainer and the rod from the
dampener piston assembly and air valve
plate,
then remove the air
valve
dampener
piston rod and spring.
10.
If it is necessary to remove the
secondary air valve
plate(s)
attaching
screws. Remove the
plates,
then
slide
the
shaft out of the air horn.
11.
If
it
is
necessary to remove the
choke plate or choke shaft, remove the
staking
marks
on the choke plate retaining
screws.
If the tips of the screws are flared
excessively,
file the flared portion to
prevent damage to the threads in the
shaft.
Remove the choke
plate,
then slide the
choke shaft and lever out of the air horn.
The choke lever is attached to the shaft
with a left hand thread screw.
12.
Do not remove the power valve
vacuum piston assembly unless it is to be
replaced.
It
is staked in place in the air
horn, and care must
be
used to avoid
damage to the air hom casting when
relieving the staked areas.
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