[Jazzjr]

I Run with my GAV completely closed off after warm up, very seldom do I open it at all.
I have rebuilt many Zeniths, And Never had Problems, They Have to be Clean, inside and out, Bead Blasted, check for Cracks, and make sure the 2 Halves are not Warped. Run a Tap and Chase all threads with right Tap, all hidden passageways cleaned out. If you read Tom Endys Carb Rebuild Pages, You Can do it Your self.
One of the best books I ever Bought, The Model A Ford Carburetors, By Paul Moller. Mine is Copyrighted 1972, and inside the front cover is marked $4, I think I bought it then 40 years ago, It is still available today.


One of the Main Problems is air Leaks around the Throttle Plate Shaft, most people do not put in new Bushings and Shaft. The extra air coming in their will mess up the best of Rebuilds.
Years ago I put together a Zenith using a Top Half Early 1928, Marked H (for Holley) and Ran a Zenith 2 Bottom. Ran Like a Charm. I do find that using Original Jets that are Numbered work best of all.

If You Read, and can Comprehend, You Can Do it Yourself. Just keep Trying and you will get it Done Right, and It will work.