Apparently the vacuum tank is not drawing the fuel from the gas tank or the line from the vacuum tank is not draining into the carburetor. First I would tap on the carburetor fuel inlet screw to unseat the needle. I use a light tap like from the handle of a screwdriver. May take several taps. If that does not solve the problem then take the fuel line off the carburetor with the valve on the vacuum tank bottom closed. Open the valve a little to see if any gas drips out. If none then it is in the vacuum tank.

@chip Thanks for your input sir. We believe we are getting fuel to both the tank and to the bowl. I'll try to unseat the needle tomorrow to see if that's the problem. If I can't get this I would like to get your price for going through one of these and rebuilding it, you can PM me your price, I'd appreciate it.

i charge $125 plus parts and shipping for the updraft Carter and Zenith carburetors.

@chip I tried tapping, didn't seem to do anything. It would start up, but then just dies out again from lack of fuel. You are talking about the screw at the bottom of the bowl, correct?

I am referring to the screw that holds the gas inlet line from the vacuum tank.

@chip you are referring to this screw?  If so, I tried tapping on it also, but to no avail. So is there a needle in there?  Should that screw be backed out?

Yes. That screw is the closest to the needle and seat so vibrating it better transferred to them.

Jeff, you might enjoy reading about when I had problems with my vacuum tank and carb: https://vccachat.org/ubbthreads.php/topics/458708/fuel-problems-investigation-and-fixes.html

Cheers, Dean