The fuel evaporating from the bowl is exactly right. There's actually very little fuel in the line, and since the fuel pump is about the same level as the bottom of the fuel tank, it can't really drain back very far.
Also, there is air in the carb between the top of the fuel level and the needle seat, so the fuel can't siphon back out of the carburetor. It will evaporate after a few days, and will have to crank it over a few extra licks to fill the bowl back up, but it can't siphon back to the pump. And what little will be in the line between the pump and the carb won't go far.
If the fuel pump is weak it may take quite a bit more cranking for it to catch up, so I can see where a new pump would help.
Another thing that would help is if the gasoline we get were better.
Kurt, replacing your carb with a Carter was likely the real fix. The poor old Rochester one barrels just aren't as good.
Last edited by Roy Rodgers; 10/11/2012 8:18 AM.
