The Ford Barn - View Single Post

CT Jack · 04-21-2022, 08:18 AM

The carburetor has 2 external adjustments, GAV (gas adjusting valve) on choke rod and the idle adjusting screw. I have a zenith carburetor and my GAV is always set at a little less than 1/4 turn open. The idle adjusting screw is set at approximately 1 turn open.
Your carburetor might have the wrong internally jets which are oversized and flowing at very high flow rate. If you change the carburetor and the mileage improves then my guess is you need to rebuild your original carburetor.
Another thought I have is you might check to see if you have a vacuum line leak between the intake manifold and the windshield wiper. You could also check to see if the gasket between the carburetor and the intake manifold is leaking.

04-21-2022, 08:18 AM	#9
CT Jack Senior Member Join Date: May 2010 Location: Hebron, CT Posts: 433	Re: Engine runs way too rich! The carburetor has 2 external adjustments, GAV (gas adjusting valve) on choke rod and the idle adjusting screw. I have a zenith carburetor and my GAV is always set at a little less than 1/4 turn open. The idle adjusting screw is set at approximately 1 turn open. Your carburetor might have the wrong internally jets which are oversized and flowing at very high flow rate. If you change the carburetor and the mileage improves then my guess is you need to rebuild your original carburetor. Another thought I have is you might check to see if you have a vacuum line leak between the intake manifold and the windshield wiper. You could also check to see if the gasket between the carburetor and the intake manifold is leaking.