I just bought a 64 Electra that has a Carter carb on the 401 nailhead. While I haven't yet experienced this problem yet, the previous owner has described a problem he had before the took the car off the road 2 years ago. The car would run very rich and raw gas would actually overflow out the top of the carb. He assumed it was a sticking float, and had the original carb replaced with a remanufactured one. He continued to have the same problem! Apparently, when the problem occurred, he 'rapped' the side of the carb with the handle of a screwdriver and it would correct the problem for a while. Because it happened on two different carbs, it doesn't sound like a carb problem to me ( but I am not a mechanic ) but some other component like the choke or throttle. Any ideas?
Thanks for the tips. So if it's dirt then a new fuel filter should help? ( I just had it replaced ) How do I check if it's getting too much fuel pressure? Just replace the fuel pump?
If the new filter doesn't help, I would open the carb (pull the metering rods first) and check for debris in the needle and seat areas (two in an AFB), check for a bad float (heavy with gas) and proper float settings. If all is in order, I would check fuel pressure. I think 7 lbs psi is max, with 5 to 6 recommended by most. You could borrow or buy a pressure guage (the last one I bought was about $15), or have a mechanic test it for you. Good luck, Frank
