Please keep in mind that all technical information given assumes our parts are being used. Parts purchased from other sources may not install, or work in a like manner.

How to Find The Carburetor Number?

The older Rochester 2G carburetors had a small triangular tag attached to the top of the carburetor. Starting in 1968 the 2G carburetor had the number stamped on the side of the float bowl.

Rochester 2GC Carburetor

Free Rochester 2GC Carburetor Manuals

Rochester 2G, 2GC Carburetor Manual


Some Rochester 2g carburetors had a hot idle compensator attached to the middle of the venturi. When heated up, the bimetal bends up, exposing a vent hole and allowing more air into the intake. This compensated for an overheating condition on vehicle at idle, especially air conditioned cars. Below is a picture of what the assembly will look like.

Hot Air Compensator

2G Power Piston

Be careful when removing the power piston. The stem can break off easily.  Push down on the stem and spring with your finger, then let it snap back. Do this over and over until the piston comes out. A frozen stem is another problem all together. Try spraying silicon spray lubricant into the vent hole, or apply heat to the outside of the piston well.

Three Basic Types

2G – Manual Choke

2GC – Automatic Choke

2GV – Divorced Choke (choke thermostat is mounted in the intake

Rochester 2G, 2GV Carburetor Catalog

2G Jets
– includes the original jet sizes we currently have listed.

Tri-Power Setup

Testing Your Accelerator Pump Circuit