My '51 Pontiac straight 8 with Carter 720S carb, cranks and runs long enough to use up the gas from the bowls, then dies. I have torn down the carb, cleaned every component. blown every orifice with compressed air, used carb cleaner, and re***embled at least a half dozen times during the last couple of weeks. Plus, I robbed components from a donor carb, building the working carb with the best parts of the two. I byp***ed the fuel pump, temporarily with an electric one, just in case the old pump is not delivering enough fuel. Accel pump is working, which seems to be the best way to keep the engine running, but when I stop pumping the accelerator, it dies. It seems that the problem would be corrected with a rather simple fix, but after 6-plus re-***emblies, I'm stumped right now. I fear that I may have lost a vital, but tiny component from the carb during my early stages of dis***embly (like a tiny steel ball, or something similar). If so, that same part is missing from the donor carb as well. I don't yet have an exploded diagram for that carb, but thought I would throw out this problem to see if others have experienced the same. Maybe there's some critical adjustment or something I'm overlooking. Any ideas?
The Jalopy Journal
