Rochester 2 Jet, 2G, 2GC, 2GV Power Circuit
|The Rochester 2 Jet power circuit includes the power piston assembly. At idle the piston is pulled up (vacuum) off of the power valve making the power valve close. As rpm is picked up vacuum drops and the piston starts to drop. Eventually it pushes the power valve open allowing extra gas to enter the system.|
|Be sure the piston rod isn't bent. It needs to press straight down on the power valve.|
|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. |
|The power piston presses down on the pin sticking out at the top, allowing extra gas to flow.|
The power valve sits on the bottom of the 2 Jet carburetor, between the 2 main jets.
The illustration on the left is for the early 2 Jet carburetors. Part #56-2. 5/16" threaded end.
This does not work on the marine 2 jet carburetor.
There are 3 other power valves to consider.
|This power valve is for the later Rochester 2 Jet carburetors. Part 56-41. 3/8" threaded end.|
|This power valve is also for the later 2 Jet carburetors. Part 56-40 . 3/8" threaded end, with the cone head.|
|This is the power valve for the Mercarb, 2 BBL marine carburetor. 56-22|