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CARBURETOR-AFB
14-61
changeable. It
is very important that these jets be in-
stalled in their respective locations in the main body
at reassembly.
(3) Again using Tool T109-58, remove the main
metering jets (secondary side), as shown in (Fig.
4).
(4)
Remove the screws that attach the primary ven-
turi (choke and pump side) to the main body. Lift the
venturi straight up and away from the main body, as
shown in (Fig. 5). Discard the gaskets.
The venturi assemblies are not interchangeable,
side for side and must be reinstalled in their origi-
nal locations at reassembly.
(5) Remove the screws that attach the secondary
venturi (choke and pump side) to the main body. Lift
the secondary venturi assemblies straight up and
away from the body, as shown in (Fig. 6).
(6) Lift the velocity valves and counterweights out
of the secondary throttle bores.
(7) Using Tool T109-59, screw driver bit, remove
the accelerator pump intake check valve located in-
side the fuel bowl, adjacent to the accelerator pump
cylinder.
(8) Remove the two idle mixture adjusting screws
and springs from the throttle body portion of the
main casting.
The carburetor now has been disassembled into
two units, namely the air horn and the main and
throttle body casting. The component parts of each
have been disassembled as far as necessary for clean-
ing and inspection.
It is usually not advisable to remove the throttle
shafts or valves unless wear or damage necessitates
the installation of new parts. During the manufac-
ture of the carburetor, the location of the idle trans-
fer ports and the idle discharge ports to the valve is
carefully established for one particular assembly, as
shown in (Fig. 7). The valves are milled to give the
proper port relation.
x
GASKET
SECONDARY VENTURI
PUMP SIDE
Fig. L R e m o v i n g or Installing Secondary Venturi
Cluster
IDLE DISCHARGE PORTS
PRIMARY THROTTLE
VALVES
SPARK
ADVANCE PORT
\
Fig. 7-Ports
in Relation to Throttle Valves
If new throttle shafts should be installed in an old
worn body,
it
would be very unlikely that the original
relationship of these ports to the valves would be ob-
tained. A very slight change in the port relationship
to the valves would adversely affect normal carburet-
or operation, between the speeds of 15 and 30 miles
per hour.
It is recommended that if the throttle shafts are
ex-
cessively worn, that a new carburetor be installed.
However, if the throttle valves have become nicked,
burred or damaged, new valves may be installed, pro-
viding the following instructions are carefully fol-
lowed.
CAUTION: The screws that attach the throttle
valves are staked on the opposite side and care
should be used in removal so as not to break the
screws in the throttle shaft. Remove the staked
portion of the screws with a file.
Remove the screws that attach the primary throttle
valves to the throttle shaft and slide valve (or valves)
out of bores.
Remove the screws that attach the secondary throt-
/SECONDARY VALVE
(BRASS)
KF 946A
PRIMARY V A L V E - '
(ALUMINUM)
Fig. 8-Throttle
Valve Identification
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