Specifications

should its long spring be broken or cor-
roded. Renew it as required.
Jets–Blow compressed air through the
main jets, the air-correction jets, emul-
sion tubes and accelerator-pump jet to
clean them. Never use a wire to probe or
clean a jet; it will disturb the flow char-
acteristics. Blow air through both sides of
the accelerator-pump delivery jet. It is a
one-way valve, so you should be able to
blow through it only one way.
Press down on the center needle of the
full-power valve to make sure it moves
freely against its return spring.
If you removed the auxiliary venturis,
blow through the passage and remove any
burrs or dirt on their surfaces.
Main Casting–Check for any damage
to the main casting. Use a straightedge to
check the base of the carburetor for
excessive warpage.
Remove the idle jets from their holders
and check each jet by holding it up to a
light. Blow through the jet if it’s clogged.
Check the diaphragm of the accelerator
pump for damage.
The automatic choke assembly con-
tains a lot of levers. Check that all oper-
ate freely. The bimetallic spring should
not be bent or broken. Check the water
chamber for signs of leakage.
Throttle Shafts–The throttle shafts
should be straight, with no visible wear
where they bear on the nylon seals.
Double-check the threads on the end of
the primary throttle shaft and the threads
on both shafts where the valves are
attached. The throttle valves should have
smooth edges and be flat.
The springs that slide onto the throttle
shafts should be strong and not de-
formed. Replace the nylon shaft seals
whether or not they show any evidence of
wear.
REASSEMBLY
The disassembly of the DGAV is, in
itself, a lesson on reassembly. After all
the components have been inspected and
damaged parts replaced, begin
reassembling the major components
first. The disassembly photos will be
helpful during assembly. Start with
either the float bowl cover or main cast-
ing. The following notes give the most
important points to remember in
reassembly.
Throttle Shafts–There are two dangers
in reassembling the throttle valves;
bending the throttle shafts and not posi-
tioning the valves correctly. The first
danger requires only care; the second,
some strategy.
The holes in the valves are oversize so
they can be positioned for a perfect seat
in the bores. The auxiliary venturis
should be removed to give free access to
the attaching screws for this operation.
Install the throttle shafts with all their
linkages and springs in place, then tight-
en the end nuts before installing the
valves. This strategy assures that the
valves are not moved while you’re
installing anything else on the throttle
shafts. On the primary shaft, working
outward from the innermost part, the
order is:
Nylon washer
Spring
Arm
Shoulder washer, shoulder side to
carburetor casting
Arm
Washer
Throttle bellcrank
Lock tab
Nut
On the secondary shaft, working out-
ward, the order is:
Nylon washer
Spring
Arm–Engage arm with slotted arm
on the primary shaft before slipping
it onto the secondary shaft.
Washer
Lock washer
Nut
Shaking throttle-shaft screws requires that you support throttle shaft. End of screw
presents itself at an angle, so a dead-center punch is impossible. Note hammer used
weighs less than five pounds. Shaft support is drive side of 1/4-in. drive socket, or
short section of solid metal rod.