Chevrolet Light Duty Truck 1973 Service Manual page 443

3. With the vacuum break diaphragm in the fully
seated position, push the choke valve toward the
closed position.
4. With the choke valve held in this position, place
specified gauge between the lower edge of the choke
valve and air horn wall.
5. Dimension should be as specified; if not, bend the
vacuum break rod at point shown, to adjust.
2GV (Fig. 8C)
Refer to Figure C and follow steps under MV.
8
4MV (Fig. 9C)
(2GV)
Fig. 8C-Vacuum Break Adjustment (2GV)
1. Seat choke vacuum break diaphragm using outside
vacuum source.
2. Open throttle valve slightly so cam follower will
clear steps of fast idle cam. Then rotate vacuum
break lever counterclockwise (towards direction of
closed choke). A rubber band may be used to hold
in place. The end of vacuum break rod should also
be in outer end of slot in vacuum break diaphragm
plunger.
3. Measure the distance between lower edge of choke
valve and inside air horn wall.
4. To adjust to specified dimension, bend vacuum
break link at point shown.
CHOKE UNLOADER ADJUSTMENT
1. Hold choke valve in closed position by applying a
light force to the choke operating lever.
E N G IN E FUEL 6 M - 1 9
(4MV)
LIGHT DUTY TRUCK SERVICE MANUAL