I seem to be having a carb flooding issue with my stock Holley 4160. The fuel pump is a Carter GP4389, which I cannot find any detaild information on. Initially, when at idle, it would flood something awful. Fuel coming out of the vents, boosters, slots, etc on both the primary and secondaries until the engine died.
I pulled the carb, replaced the needle and seats as the old ones had worn o-rings. I could use my mouth and blow past the o-ring while holding the float in the closed position. After replacing with new needles and seats, I can no longer do this. At the same time, I replaced all gaskets with blue non sticks and cleaned out every orifice I could with several cans of carb spray while the bowls and metering blocks and plates were off.
When I got the carb back on, and started her up, it idled perfect for about 10 seconds or so, then it started to flood out of every orifice again like I did not spend any time, money, blood (cut myself on the carb), and sweat on the piece of sh**! Like the effort I put in it and the trips to the parts store was just imaginary.
What PSI does it take push past a new set of needles and seats? I did notice that it will not flood when I bottom the float adjustment out to the point where the hex nut no longer is in contact with the needle and seat. It will however drain the bowl. At the slightest adjustment back out it will fill the bowl and flood out. The floats seemed fine when I had the bowls off, in fact, the primary was brass while the secondary was composite. Both materials cannot fail at the same time!?
What else do I need to look for before I drop all kinds of cash on a new fuel system and carb?