Rochester Monojet Carburetor

The 1MV monojet carburetor is a single down draft unit using a triple ventuir in conjunction with the plain tube nozzle. The main venturi is 1 7/32″ in diameter and the throttle bore is 1 7/16″.
Fuel flow through the main metering system is controlled by a main well air bleed and a fixed orifice jet. A venturi velocity power enrichment system is used to provide good performance during moderate to heavy acceleration and at higher engine speeds.
An exhaust gas recirculation, E.G.R. system controls oxides of nitrogen emissions. The E.G.R. valve is operated by a vacuum signal taken from the carburetor throttle body.
A vacuum supply tube installed in the carburetor throttle body connects by a passage to timed vertical ports located in the bore of the throttle body and float bowl. The ports provide a vacuum signal to the E.G.R. valve in the off idle and part throttle operation of the carburetor.
The E.G.R. valve, mounted on the intake manifold, circulates a metered amount of exhaust gases to the combustion mixtures to lower peak combustion temperatures, thereby reducing oxides of nitrogen during these ranges of engine operation.

The E.G.R. system is not in operation during the engine idle.

A pleated internal paper fuel inlet filter is mounted in the float bowl behind the fuel inlet nut to give maximum filtration of incoming fuel.

The carburetor has an aluminum throttle body, a thick throttle body to bowl insulator gasket, and a internally balanced venting through a vent hole in the air horn which leads into the bore beneath the air cleaner. The float bowl is externally vented under extreme conditions through a pressure relief valve system.

The carburetor part number is stamped on vertical section of float bowl, next to fuel inlet.

An idle stop solenoid is used to control idle. The solenoid is electrically  controlled through the ignition switch. When the ignition switch is tunred off, the solenoid is denergized, allowing the carburetor throttle valve to close further, preventing the engine from running after the ignition switch is turned off. On manual transmission models, the  solenoid also deenergizes when the clutch is disengaged.

Rochester Monojet Identification

Monojet Identification

1980 Monojet 1ME Exploded View & Parts List

1981-85 Monojet 1ME Exploded View & Parts List

1985 & Later Monojet 1MEF Exploded View & Parts List

Float Level Adjustment

Monojet Float Level

Fast Idle Cam Adjustment

Monojet Carburetor

Vacuum Break Adjustment

Monojet Carburetor

Choke Coil Lever Adjustment
Quadrajet Adjustment

Trouble Shooting the Monojet M MV Carburetor

Adjust the Idle Mixture


Recent Posts

Tri-Power Carburetors

Rochester Tri-Power carburetor kits. These are
the 2G and 2GC carburetors. The 2GC is the carburetor in the middle and
would have the automatic choke attached. The front and rear carburetor
does not have a choke.Selecting kits for the tri-power carbuetors is straight forward if you
still have the tags attached to the top of the carburetor. Rochester
did not stamp the carburetor number in the side of the carburetor until
1968.Tri-power carburetors use two different carburetor kits. One kit for
the center and the other kit for the front and back carburetors. Each
kit services one carburetor, so to do all three carburetors you will
need three kits.

Be careful because chances are you may not have the original
carburetors. It is rare that we see a tri-power setup that has the
correct carburetors (numbers matching).

Here is an example of a tri-power setup. Notice that the front an rear
carburetors use the same carburetor kit, but the center carburetor uses
a different kit.

1959-61 Chevrolet V-8 A/T NO AIR

7013015 FRONT CARBURETOR Tri-Power Carburetor Kit K6121
7013017 REAR CARBURETOR Tri-Power Carburetor Kit K6121
7013016 CENTER CARBURETOR Tri-Power Carburetor Kit K636

What if you don’t have the carburetor tags?

You have to make the best guess and the suggested way is to take the
carburetor apart and carefully compare the old parts with the parts we
have illustrated in the photos, or videos.

Here are the typical carburetor kits used on the Chevrolet carburetors
(prior to 1968)

K636

K355

K427

K6121

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