Chevrolet 1973 Overhaul Manual page 204

NOTE: Make sure retaining pin is held
firmly in place and tang of float needle is
seated on float needle.
b. Bend float up or down for proper adjustment.
14. Install power piston spring in power piston well. If
primary main metering rods were removed from
hanger reinstall making sure that tension spring is
connected to top of each metering rod. Install
power piston assembly in well with metering rods
properly positioned in metering jets. Press down
firmly on power piston retainer to insure engage­
ment of retaining clip.
15. Install plastic filler over float needle, pressing
downward until seated properly.
16. Install pump return spring in pump well.
17. Install air horn gasket around prim ary metering
rods and piston. Position gasket over two dowels on
secondary side of bowl. Press power piston down
firmly to assure correct alignment engagement of
pin.
18. Install pump plunger in pump well.
Air Horn Assembly
1. Install choke shaft, choke valve and two attaching
screws, if removed. Make sure that the two choke
valve screws are lightly staked in place.
Air Horn to Float Bowl Installation
1. Place air horn assembly on bowl, carefully
positioning vent tubes and accelerating well tubes to
air horn gasket. Do not force air horn assembly on
to float bowl as distortion of the vent tubes may
result.
2. Install two long air horn screws, five short screws
and two countersunk screws in prim ary venturi
area. All screws must be tightend evenly and
securely (Figure Q7).
3. Connect pump lever to upper pump rod by rotating
Fig. Q7-Air Horn Tightening Sequence
lever into rod. (Pump rod should be in inner hole).
Then install pump lever into air horn casting and
push pump lever pin back through casting until
flush with casting.
4. Connect choke rod into lower choke lever in float
bowl cavity and retain in upper lever with retaining
clip.
5. Install air valve to dashpot rod into air valve shaft
lever hole and into the slot in the dashpot plunger;
then position dashpot into retaining bracket. Crimp
over ears on retaining bracket and connect the
vacuum hose from the unit to tube on float bowl.
6. Install secondary metering rod and hanger. Rod
should be positioned with upper ends through
hanger holes and towards each other. (Figure Q8).
Install hanger retainer screw and tighten securely.
Installation of the Electrically Operated Idle
Stop Solenoid
1. Install the idle stop solenoid into locating lug in
bracket on float bowl.
2. Install large retaining nut and tighten securely.
Then, bend locking tabs from lockwasher over flats
on the retaining nut.
CAUTION: Do not over tighten the large
retaining nut on the idle stop solenoid as
bracket distortion can result.
NOTE: After carburetor overhaul, throttle
body part replacement, mixture needle part
replacement, or limiter cap and needle
removal for any reason, the procedures in
Section 6M, 1973 Chassis Service Manual,
under "Additional External Settings and
Adjustments", must be followed.
CARBURETORS 6 M - 2 5
OVERHAUL MANUAL