Advertisement
14-28
CARBURETOR-BBD
1
' / 4
INCH
ing it on the correct carburetor fitting. Refer to (Fig.
1). Do not connect the vacuum hose to the dia-
phragm fitting until after the vacuum kick adjust-
ment has been made. (See Carburetor Adjustments.)
ADJUSTMENTS
It is very important that the following adjustments
be made on a reconditioned carburetor, and in the
se-
quence listed:
Accelerator Pump and Bowl Venf
When assembling the accelerator pump to the air
horn, note that the hair pin clip (which opens the
bowl vent) can be placed in any one of the three posi-
tioning notches. These notches correspond to the long,
medium and short pump stroke holes in the throttle
lever. Normally, the bowl vent clip on the pump stem
will be at the middle notch and the pump operating
rod in the medium stroke hole.
The proper procedure is to adjust the amount of
bowl vent opening instead of measuring and setting
the height of the pump plunger.
To check or set the adjustment, proceed as follows:
(1) Back
off
the idle speed adjusting screw. Open
the choke valve so that the fast
idle cam allows the
throttle valves to be completely seated in the bores.
(2) Be sure the pump operating rod
is
in the me-
dium stroke hole in the throttle lever, and that the
bowl vent clip on the pump stem is in the center
notch.
(3) Close the throttle valves tightly. It should be just
possible to
insert
a
'Ile
inch drill between the bowl
vent and its seat, as shown in (Fig. 12).
If an adjustment is necessary, bend the pump op-
erating rod, using Tool T109-213, at the lower angle,
until the correct bowl vent opening has been obtained.
Fig. 72-Measuring
Bowl Vent Opening
This is an important adjustment, since too much
lift at
the
bowl vent will result in considerable
loss
in low speed fuel economy.
Remember that if the pump operating rod is moved
to either the short or long stroke position, a corre-
sponding change must be made in the location of the
bowl vent clip, and the amount of lift of the bowl
vent rechecked and adjusted.
Fast Idle Speed
and
Cam Position
Adjustment
The fast idle engine speed adjustment should be
made on the vehicle, as described in the Fast Idle
Speed Adjustment (On the Vehicle) Paragraph. How-
ever, the Fast Idle Cam Position Adjustment can be
made on the bench. This adjustment is important to
be sure that the speeds of each cam step occur at
the proper time during the warm-up. Adjust as follows:
(1) With
the fast idle speed adjusting screw con-
tacting the step on the fast idle cam shown in (Fig.
13), move the choke valve toward the closed position
with light pressure. Insert a
'ler
inch (manual trans. or
automatic trans.) drill or gauge between the choke
valve and the wall of the air horn.
(2) An adjustment will be necessary if a slight drag
is not obtained as the drill or gauge is being removed.
(3) If an adjustment
is necessary, bend the stop of
the shaft lever, using Tool T109-22, until the correct
valve opening has been obtained. Refer to (Fig. 13).
Vacuum Kick Adjustment4This test can be
made
On
or
Off
the vehic1e.J
The choke diaphragm adjustment controls the fuel
Fig. 7
3-Fast
Idle Cam Position Adlustrnent
Hide quick links:
Advertisement
