Chevrolet Corvette 1963 Repair & Tune-Up Manual page 178

160 EMISSION CONTROLS AND FUEL SYSTEM
Installing the lower choke rod lever—Quadrajet®
typical
Assembly is the reverse of the previous
steps. Note the following points during as-
sembly:
a. Install the lower choke rod lever as
shown in the accompanying illustration.
b. When installing the float and needle,
DO NOT put die needle clip into either of
the float bracket holes. The clip must be
installed as shown in the accompanying il
lustration.
c. Install the plastic filler block BE
FORE the metering rods and hanger.
When installing the primary metering rods,
make sure the rod tips are positioned in
the primary jets, then lower the power pis
ton. To seat the plastic power piston re
tainer, evenly push it into the top of the
piston bore with a small screwdriver.
FLOAT NEEDLE PULL CLIP LOCATION
DO NO
HOOK
CLIP If
THESE
Correct positioning of the float needle clip—DO NOT
put the clip into either of the float bracket holes—
Quadrajet®
Quadrajet® air horn screw torque sequence
d. When installing the air horn assem
bly, be sure to follow the accompanying
torque sequence diagram for the air horn
screws.
e. When installing die accelerator pump
lever and rod, engage die lower end of the
rod into the throttle linkage, and align the
lever pivot hole with the pivot pin. Push
die pin through by carefully prying it widi
a screwdriver (between the pin and die
choke plate wall).
C.E.C. VALVE MAINTENANCE—1971
QUADRAJET ONLY
The Rochester 4MV Quadrajet has a number
of revisions for 1971 which include: calibra-
tion changes, greater capacity accelerator
pump, increase in die size of the vacuum
break diaphragm restriction to 0.020 in., a
beefed-up, choke-closing assist spring, re-
moval of die wide open kick lever from die
choke unloader mechanism and its replace-
ment widi a tang on die fast-idle lever diat
contacts the fast-idle cam and forces the choke
valve to admit more air under flooded engine
conditions, and die adaption of a combination
emission control valve (C.E.C. valve). This
valve increases the idle speed during high
gear overrun and helps to control normally
unburned hydrocarbons. The mixture is set
at the factory and die idle-mixture screws are
capped to prevent adjustment in die field.
When disassembling die carburetor, re-
move die C.E.C. valve from die carburetor
but leave the valve bracket attached to die
carburetor. Do not immerse die C.E.C. valve
in carburetor cleaner. Disassembly practices
differ in die 1971 4MV due to calibration