I purchased this Carb on Ebay last fall. Minimal if any previous usage. Been sitting on a Shelf  for awhile. Has the old style Black Bowl and plate Gaskets. Accelerator Diaphragm was flat which I replaced as well as removing the Bowls and blowing out Passages and installing Steel Needle and Seats.and setting Float Levels. I have a 390 CFM  on mine now and it runs great so  I know the Problem is with this Carb and nothing else. It starts but won't stay running without pumping the Gas. It will run at fast speed but dies as soon as the Pedal is released. Won't Idle to set it up at all.I have set the throttle  plates so the transfer slot is just showing so thats not the Problem. I bought this Carb to either install on my Buddies 56 and changing the Distributor or keep it on mine and give Him the 390 which is already setup from being on mine. Any Ideas on what to check before I put mine  back on if I cant get this One to work? Thanks