I am working on a 1927 Chevy national with a 1928 engine in it.
I am trying to bring it back to the original fuel system. I removed the electric fuel pump and modern carburetor.
I bought a rebuilt Stewart’s vacume tank and installed a RAKX-O carburetor kit.
I installed new copper tubing and made sure the connections were tight.
Problem, the engine will run fine, speedup quickly, and then try to smooth out.
Is this normal operating or is there an air leak. I am not use to working with a vacume tank system.
The other issue is that I am dripping gasoline from the carburetor bowl and the fuel supply connector to the carburetor. I cleaned the fuel supply connector to the carburetor and installed new gaskets and fuel metering pipe. It has a very slow seepage at the base of the fuel supply connector to the carburetor.
The other leakage is that the carburetor bowl is seeping. I put on a new bowl, new bowl nut and gasket. I have snugged up the bowl and it seeps. How far to turn the nut without stripping the threads the nut screws into to stop leakage?
Thank you for your help- Paul

I don't understand the problem with the carburetor performance. Is the speed up with the throttle in the same position? If so there may be a vacuum leak or the vacuum tank may be drawing fuel from the fuel tank. It is common to get a little rougher running when drawing in fuel. There should be a tube with small hole in the intake connection to minimize the roughness.

If you have solid copper tubing from the vacuum tank outlet to the carburetor inlet, there probably is enough stress on the inlet for a little seepage. A full loop in the tubing or a section of rubber hose will allow any difference in movement of carburetor and vacuum tank to be negated.

The RAKX-0 originally had a gasket both inside the bowl and outside at the nut to provide a better seal. If a new replacement bowl was used some of them have a ridge on the inside of the bowl around the center hole. If it holds the bowl away from the casting a seep is likely. The fiber gasket(s) may need to be soaked in water to soften them a bit so they can fill imperfections.

Thank you for your suggestions. The copper tubing does not have a loop in it. I will replace it with a loop in the vacuum line.
The rebuild kit does not have quality photos to follow the rebuild process. I did not realize that a gasket inside the bowl.
Again, I really appreciate member's help to keep the cars running. Paul

The fuel pump is both vacuum and gravity fed to the carb. There is a weep hole on the carb. just above the bowl. Did you install a shut off valve on the fuel line between the pump and the carb? If not you should.

Paul just a random thought, are you using a vented fuel cap? A sealed cap will build pressure in the fuel system and will cause leaking as the pressure rises in the tank. I had a similar problem gas every where after a replaced the cap. Remedy drill a whole in the center of the cap to keep equilibrium.

Although I agree with Chevygoat that the cap in the gas tank must be vented, I respectfully disagree that pressure will build in a tank with no vent.

The opposite occurs. When there is no vent in the gas cap, the gas draws down as the vacuum tank sucks gas out of it. The result is that a partial vacuum develops with no venting, so the gas flow slows down to a trickle and the engine eventually becomes gas starved.

I've had this happen to me.

Cheers, Dean

Pressure will build up if you fill up with cool gas from the pump and then park it in the sun if you don't have the tank vented.

Thanks to everyone who responded to my inquiry. All of you have been helpful. I discovered the bowl nut threads are stripped. I am working with Chipper to repair the carb. I love this forum-Paul