Technical Flathead carburetor issues

I am have some issues with the carb that is on the flathead in my 1950 mercury. It is a Holley 94 carburetor and has recently be rebuilt. As of right now I can get the car to idle good and with run good will driving in first gear right after start up. But as soon as I start accelerate the car will fall flat on its face and will act like it’s not getting any fuel. After this happens I can’t get the car to idle right or run good in first gear until I shut it off and let it sit for a few minutes.

My dad has a 1949 F-3 pickup with a flathead in it with a Holley 94 carb. I took the carb off his truck and put it on my car to see if it acted any differently and it did! The car ran perfectly. So I figured it would have to do something with the power valve and jets that are in the carb.

So I replaced the 8.5hg power valve with a 7.5hg and the 56 mm jets with 52mm jets. To match what the truck carb had and no luck. The car still falls on its face as soon as you start to accelerate.

I have gone though the carb on the car a few times now making sure all the p***ages are cleared out of any gunk.

At this point I’m lost on what could be going on and I’m wondering if anyone might have some words of wisdom for me. Thanks In advance!

 

If you don't get any wisdom here contact Charlie NY on the Ford Barn. He can shed some light on the problem. Or you can send your carb to for a rebuild and it will perform perfectly when you get it back. H rebuilt the 94 for the 8ba in my '39 p/u. Still runs like a top.

 

How are you cleaning the carb. If you are not soaking it (completely dis***embled) in a good immersion type of carb cleaner you may not be getting all the p***ages and other small parts as clean as they need to be to work properly.

 

Where are you from? There might be someone near you to give you a hand.

 

Just a thought but have you checked your float level?

Possibly if it is low then it might just be getting enough to run initially but might not be getting enough fuel at higher revs (once the gas that is in the float bowl is used up)?

 

Could it be a vacuum leak? How is the fit of the main shaft? If it is a loose fit some air may be p***ing between it and the housing.