Introduction; Rochester M And Mv (Monojet) - Chevrolet 1973 Overhaul Manual

Introduction.......................................................................... 6M-1
Rochester M and MV (M onojet).................................6M-1
Rochester 2GV (SAE l 1/4)..........................................6M-9
SEE ROCHESTER CARBURETORS IDENTIFICATION,
FIG. Ml
Various carburetors, designed to meet the particular
requirements of engines, transmission and vehicles, are
used on passenger vehicles and although carburetors
may look alike they are not always interchangeable.
Refer to carburetor part number and/or 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. Although illustrations

ROCHESTER M AND MV (MONOJET)

General Description...........................................................6M-1
Disassembly.......................................................................... 6M-3
Air H orn......................................................................6M-3
Float Bowl...................................................................6M-3
Throttle Body..............................................................6M-4
Cleaning and Inspection.........................................6M-5
The model MV (Fig. M2, M3, M4 and M5) carburetor used on
the Chevrolet, 6 cylinder engine is a single bore, down draft
unit using a triple venturi in conjunction with a plain tube
nozzle. The main venturi is 1 5/16" in diameter and the
throttle bore is 1 11/16".
Fuel flow through the main metering system is controlled
by a main well air bleed and a variable orifice jet. A
power enrichment system is used to provide good
performance during moderate to heavy acceleration and
at higher engine speeds.
SECTION 6M
CARBURETORS
CO NTENTS OF THIS SECTION
NOTE: Also refer to the Emission Control
Systems" Booklet for required maintenance
and warranty information.
Rochester 2GV (SAE l 1/2)..........................................6M-15
Rochester 4MV (Q uadrajet)........................................... 6M-21
Special Tools........................................................................6M-26

INTRODUCTION

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.
INDEX
Assembly and Adjustments.............................................6M-5
GENERAL DESCRIPTION
The idle system with passenger car automatic transmis­
sion incorporates a hot idle compensator to maintain
smooth engine idle during periods of extreme hot engine
operation.
The model MV carburetor has an automatic choke
system. The vacuum diaphragm unit is no longer an
integral part of the air horn, and connects to the choke
valve lever through a connecting link. The choke coil is
mounted on the manifold and is connected to the choke
valve lever by a rod.
An internal fuel inlet filter is mounted in the fuel bowl
CARBURETORS
CAUTION: I f the C.E.C. solenoid on the
carburetor ( L-6 L /D engines only) is used to
set engine idle or is adjusted out o f limits
specified in the Service Manual, decrease in
engine braking may result.
Throttle Body..............................................................6M-5
Float Bowl................................................................... 6M-7
Adjust Float Level.................................................... 6M-8
Adjust Metering R od...............................................6M-8
Air Horn Assembly and Installation.................6M-9
6M-1
OVERHAUL MANUAL