Chevrolet 1977 10 Series, Repair Manual, Page: 195 / 468

CARBURETOR 6C-1
SECTION 6C
CARBURETOR
A L L N EW 1977 CH EV RO LETS A R E C E R T IF IE D BY T H E
U N IT E D STATES D E P A R T M E N T O F H E A L T H E D U C A T IO N
A N D W E L F A R E AS C O N F O R M IN G TO T H E R E Q U IR E M E N T S
O F T H E R E G U L A T IO N S F O R T H E C O N T R O L O F A IR
P O L L U T IO N
FR O M N EW M O TO R V EH ICLES. TH IS
C E R T IF IC A T IO N IS C O N T IN G E N T O N C E R T A IN
A D JU ST M E N T S B E IN G SET TO FA C TO R Y ST A N D A R D S. FO R
TH IS R EA SO N , T H E FA C T O R Y P R O C E D U R E F O R SE T T IN G
IG N IT IO N T IM IN G , A N D SLOW ID L E M UST BE FO L L O W E D
EX A C TLY W H E N A D JU STM EN TS A R E M A D E.
CONTENTS OF THIS SECTION
In tro d u ctio n ................................................................................................. 6C-1
Model 1 M E C a rb u re to r........................................................................... 6C-1
M odel 2G C /2G V C arb u reto r................................................................. 6C-7
M odel M 4M C /M 4M E C arb u reto r........................................................ 6C-13
M odel 4MV C arb u re to r........................................................................... 6C-22
Special T ools................................................................................................ 6C-28
INTRODUCTION
A carburetor is designed to meet the particular
requirem ents of the engine, transmission and vehicle and
although they may look alike, they are not always
interchangeable. Refer to carburetor part num ber an d /o r
specifications.
This section, divided into sub-sections by carburetor
model, covers the repair procedures for the various
carburetors, assembly and disassembly procedures and
internal carburetor adjustment. A lthough illustrations
showing bench operations are used, most single operations,
when not part of a general overhaul, should be performed (if
practical) with the carburetor on the engine. Typical
illustrations and procedures are used except where specific
illustrations or procedures are necessary to clarify the
operation.
Refer to Passenger C ar or Light Duty Truck Service
M anual Section 6C for external carburetor adjustm ent
procedures.
MODEL 1 ME CARBURETOR
DISASSEMBLY
Place carburetor on a holding fixture to prevent damage
to throttle valve (Fig. 6C-1 and 2).
Air Horn
Removal
1. Remove choke vacuum break diaphragm hose.
2. Remove vacuum break diaphragm assembly from air
horn by removing two attaching screws. These screws have
a tapered head and do not use lockwashers. Remove
diaphragm plunger stem from diaphragm to choke lever link.
(Fig. 6C-3).
CAUTION:
Screw that retains vacuum break lever
to choke shaft is installed with thread torque
retaining compound. It is not necessary to remove
this screw and lever unless choke shaft replacement
is required.
3. Remove fast idle cam attaching screw; then remove
fast idle cam (Fig. 6C-4).
Remove choke rod from choke coil lever on end of choke
shaft.
4. Remove electric therm ostatic coil assembly from
choke housing by removing (3) screws and retainers.
5. Choke coil housing need not be removed from float
bowl unless replacem ent is necessary. To remove choke
housing, remove three attaching screws from float bowl. Two
screws have lockwashers and the one facing the choke
housing has a tapered head for locating choke housing.
6. Remove four remaining air horn to bowl attaching
screws and lockwashers (three long and one short screw).
7. Remove air horn by lifting and twisting back towards
choke housing so that the choke coil lever link will disengage
from the choke coil lever at the choke housing, invert and
place on clean bench. A ir horn to float bowl gasket can
remain on bowl for removal later (Fig. 6C-5).
Disassembly
1. If required, the choke valve and choke shaft can be
removed from air horn by removing the screw that retains
the vacuum break lever to the choke shaft. Care should be
exercised when removing this screw because it is retained in
place by thread torque retaining compound. Remove the two
attaching screws from the choke valve, then, remove the
choke valve and choke shaft from air horn.
NOTE:
The choke valve screws are staked in place so