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  5. Marine 2G Rebuild - Dissassembly
Rochester 2G

The 2 barrel carburetor is available in two different models: 2GC and 2GV. The model 2GV has an automatic choke with the thermostatic coil installed on the engine manifold. The coil is then connected to the choke valve through linkage. This model has a vacuum break diaphragm on the carburetor instead of the conventional choke housing on the air horn. The model 2GC has the automatic choke as a part of the carburetor (intragal).

Rochester 2G Choke
Rochester 2G IdleRochester 2G Main Metering2G Power CircuitRochester2G Marine


Carburetor Marine
Remove the idle vent valve and the pump link. Remove the screw at the end of the choke shaft, then remove the fast idle linkage as an assembly. Remove the air horn attaching screws and lift the air horn straight up from the body.Marine 2G

Disassemble the automatic choke by first removing the two choke vave retaining screws. However, under normal conditions, the choke shaft is not removed. You may have to file the staked ends of the screws in order to remove them. Lift out the choke valve. Remove the choke cover, with the thermostatic coil attached, the gasket and the baffle plate. Now, rotate the choke shaft conter clockwise to guide the piston from its bore. Remove the shaft and piston assembly.

Marine Carb

Turn the air horn upside down and remove the float hinge pin. Lift off the float, and remove the float needle. Depress the power piston shaft which will allow the spring to snap and in turn will force the piston from the casting and allow the power piston to be removed. Remove the accelerator pump plunger, pump lever and shaft assemly. Remove the two choke housing to air horn attaching screws and lift off the choke housing. Discard the gasket.

Marine Carburetor

Remove the pump plunger, return spring, main metering jets, and power valve from the main body. Some models have an aluminum inlet ball in the bottom of the pump well. This ball will fall out when the carburetor is turned over. Remove the venturi cluster by removing the attaching screws.

Marine 2G Carb

Use a pair of needle nosed pliers to remove the discharge ball spring T shaped retainer. Now, take out the pump discharge spring and the steel discharge ball. Turn the carburetor over and remove the three throttle body to bowl attaching screws. Lift off the throttle body. Do No disassemble the throttle body. Replacement parts are not available because of the close relationships between the throttle plates and the idle ports. In th event you need to remove the throttle plates, mark the plates and throttle body with an awl so that the plates are replaced in the same exact position.


Soak your carburetor parts overnight in a good cleaner. Examples are Zep Carburetor Cleaner, or perhaps Gunk Hydro Seal II, # HS5LB.

Wash the parts with hot water then blow out all passage ways. Run very thin wire through the passage ways and small orifices in order to remove the residue left behind by Ethanol. Be gentle. You don't want to enlarge any of the holes.

Move the throttle shaft back and forth checking for excessive wear. Some wear is ok, maybe less than 1/32". Anything more than that could cause a vacuum leak, which will result in a rough idle.
2 Jet Parts
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