2GC Automatic Choke

[Scott_a_ro]

Hello All,

I have a rochester 2gc carburetor. The Automatic Choke has to be way lean just so it will idle. When I run it full out, after a minute or less it will sputter and die. playing with it, I noticed the choke is all the way open when i go fast, when it starts to sputter out, I can just slightly close the choke and it will get gas and go again for a minute then repeat itself. Could there be a problem with my choke? It is heat driven from the manifold. I have cleaned the carburetor and replaced everything I could with the carb kit.

Thanks,
Scott

 

[Bondo]

Re: 2GC Automatic Choke

I can just slightly close the choke and it will get gas and go again for a minute then repeat itself. Could there be a problem with my choke? It is heat driven from the manifold. I have cleaned the carburetor and replaced everything I could with the carb kit.

Nope, it ain't a problem with the Choke,...
But, the choke is tellin' ya the carb is runnin' too Lean....
Ya either screwed up the rebuild, or the carb is past rebuildin'...

 

[NetDoc]

Re: 2GC Automatic Choke

Carbs are creatures of vacuum. The gas is literally sucked out of them by the passing air. Vacuum leaks and low float levels will cause the condition you describe. You can check for a vacuum leak by very carefully spraying around gasket areas with carb cleaner (be sure to be adequately ventilated). Don't forget the throttle shafts on the carb. There should be an immediate change in the running if/when you hit a leak. If that checks out, check your carb fuel level (after its been running). Most fuel bowls should be half to two thirds "full" with the top of the carb pulled off. This is a function of the fuel delivery system or the float setting. Remember, a small leak upstream from the fuel pump will suck a lot of air and just a little fuel.