The Stovebolt Site Forums The Shop Area Engine Shop flooding carb, fuel in manifold

I just installed Langdon's holley/weber 2bbl with adapter and when starting the first time the fuel overflowed and was coming ot the top of the carb, then the engine flooded and stopped.
I removed the top of the carb and checked and adjusted the float level to 31/64 upside down.
that was the only adjustment info sent with the carb. I got the engine running and was warming it up when it kept wanting to stall. I tried to adjust the fuel mixture and closed the screw all the way in, but there was no change in idle speed or character. To prevent stalling at idle I increased the idle speed screw setting. It was making a sputtering noise at the carb without throttle. Almost as though fuel was being pushed through the carb instead of being succked through. Now there is pooled fuel in the manifold visible through the carb and the engine will not start. I have a recently rebuilt 235 (Good compression, new plugs points and everything). The fuel pump is new and is the pump/vacuum combo from chevs of the 40s. When I disconnected the fuel line to carb to adjust the float the fuel squirted out with lots of pressure. Is this normal or not? And, Is this causing the flooding? Why is there excess fuel in the manifold?

boerdoc, I have the same problem except with a rebuilt single barrel Carter. New fuel pump puts out pretty good gush of fuel. I've adjusted the float to spec. Still floods the engine.

I've been told that flooding is most likely caused by debris at the needle and seat. I've had suggested that a fuel filter at the fuel inlet may prevent debris in the line from messing with the needle. Teflon tape on the threads has been another culprit with the needle.

I don't know about you, but these suggestions just don't stop it. I'm wondering if there is too much fuel pressure and how would you correct that? Otherwise I'd like to hop in on your questions as well.

Kyle

I cannot answer the question on the H/W.

As to the Carter, the most common source of flooding is an incorrect fuel valve. The parts store repair kits have a fuel valve with an orifice designed for a Foord 300 CID which is MUCH larger than the one for the Chevrolet. The correct size for the 235 is 0.081 with a spring-loaded valve. The size for the 300 is 0.101 and a solid valve.

Assuming the proper valve is in place, the carburetor should accept fuel pressure up to about 4 and 1/2 pounds.

If you have excessive pressure, then the fuel pump should be checked. There is a source of rebuilt fuel pumps for antique cars that has a quality control (if the part fits, its the right part!) attitude issue. Pump pressure is regulated by the diaphram spring. Kits containing the proper parts may be acquired from the Antique Auto Parts Cellar, located in Boston.

The dial-type pressure regulators are extremely useful, assuming you have a rabbit problem in your garden, and a strong right (or left) arm!

They may also successfully be used as paper weights if they have not been placed in service, and therefore dirty.

Re-iterating - if you have a pressure problem, fix it at the source - the pump.

Jon.