Chevrolet Chevelle 1977 Repair Manual page 199

C L E A N IN G A N D IN S P E C T IO N
The carburetor should be cleaned in a cold immersion
type cleaner.
1. Thoroughly clean carburetor castings and metal parts
in an approved carburetor cleaner such as Carbon X (X-55)
or equivalent.
NOTE: R ubber and plastic parts should not be
immersed in carburetor cleaner. However, the air horn
which has the plastic relief valve will withstand normal
cleaning in carburetor cleaner.
2. Blow out all passages in castings with compressed air.
Do not pass drills through jets or passages.
3. Examine float needle and seat assembly for wear.
Install a new factory matched set if worn.
4. Inspect upper and lower casting sealing surfaces for
damage.
5. Inspect holes in levers for excessive wear or out of
round condition. If levers are worn they should be replaced.
6. Examine fast idle cam for excessive wear or damage.
7. Check throttle and choke levers and valve for binds
and other damage.
8. Check all springs for distortion or loss in tension;
replace as necessary.
NOTE: When carburetor has been disassembled, new
gaskets and filter must be used.
C A R B U R E T O R A S S E M B L Y
Throttle Body (Fig. 6C-12)
1. If removed, install idle m ixture needle and spring into
throttle body until lightly seated. Back out two turns as a
preliminary adjustment. Final idle m ixture adjustment will
be made on vehicle.
2. Invert float bowl and install new throttle body to bowl
insulator gasket.
3. Install throttle body on bowl gasket so all holes in
throttle body are aligned with holes in gasket.
4. Install two throttle body to bowl attaching screws and
lockwashers. Tighten even and securely to 20 N.m (15 ft.
lbs.).
Float Bowl
1. Install fuel filter spring, filter, and check valve
assembly, (if used), inlet nut and gasket rubber seal on check
valve faces fuel inlet nut.
The fuel inlet check valve m ust be
CAUTION:
installed (where required) in the filter to meet
Motor Vehicle Safety Standards (M. V.S.S.) for roll­
over. New service replacement filter include the
check valve, where required.
2. Install idle stop solenoid and spring, if removed.
Adjust later for correct idle speed.
3. Install main metering jet into bottom of fuel bowl.
Tighten securely.
4. Using wide blade screwdriver install needle seat and
gasket.
5. Install idle tube flush with bowl casting.
6. Install pump ball, spring and "T" into pump discharge
hole (Fig. 6C-10).
7. Drive pump discharge "T" in until flush with bowl
casting.
8. Install accelerator pum p return spring.
9. Install power piston return spring into piston cavity
in the bowl.
10. Install lower end of pum p link into actuator lever
CARBURETOR
which fits on throttle shaft. Ends of link point toward
carburetor. Bend in link faces fuel inlet nut.
11. Install curved power piston actuator link into
throttle actuator lever. End protrudes outward away from
throttle bore and has tang which retains link to lever.
12. Install pum p plunger assembly into pump well with
actuating lever protruding through bottom of bowl casting.
Push downward on pum p lever and install pump assembly
drive link into slot in lower end of shaft. Tang on upper end
of link retains link to pump shaft (Fig. 6C-13).
13. Assembly metering rod to holder on power piston.
Spring must be on top of arm when assembled correctly. Then
install power piston actuating rod (right angle end) into slot
in the power piston.
14. Install power piston, metering rod and drive rod
assembly into the float bowl. End of drive rod must enter hole
in bowl and end of metering rod into jet.
15. Before fastening power piston and pump actuator
lever to end of throttle shaft, hold power piston assembly
down and slide upper end of curved power piston actuator
link into lower end of power piston actuating rod.
16. Install actuating lever on end of throttle shaft by
aligning flats or lever with flats on shaft. Install lever
retaining screw and tighten securely.
17. Install float needle valve on to float arm hooking pull
clip over edge of float arm.
18. Install float hinge pin into float arm. Install float
needle into seat and float with hinge pin into float bowl.
Hinge pin should in locating channels in float bowl.
Float Level Adjustm ent (Fig. 6C-14)
1. Hold float retaining pin firmly in place push down on
float arm at outer end against top of float needle, as shown.
2. Use adjustable "T" scale and measure distance from
top of float at index point on toe to float bowl gasket surface
(gasket removed).
3. To adjust, bend float pontoon up or down at float arm
junction.
Fig. 6C -13 --P u m p D rive Link
6C-5