If the fuel delivery system is stock, then the YF used on Chevrolet engines WILL flood if the typical FLAPS fuel valve is used.
If an electric pump has been added, then the addition of a regulator with a bypass is pretty much mandatory.
The typical inline dial type regulators from your FLAPS regulate pressure by restricting volume. If the engine is used in a race vehicle, and using the rated fuel flow capacity of the regulator, the the regulator will work (sort of). If the engine is at idle, changes are good the output pressure from the regulator is IDENTICAL to the inlet pressure.
These regulators are quit useful.......................IF you have a strong right arm, and a rabbit problem in your garden.
Adding a bypass regulator may still not solve a flooding issue if the FLAPS kit fuel valve is used.
The most common valve used in the YF carbs designated for Chevrolet use is part number 25-239s, with an orifice of 0.081 inch. The typical FLAPS valve would be a non-spring-loaded replacement for 25-1076s with a 0.101 inch orifice.
Jon
Thanks Jon, I installed the electric pump simply to rule out a problem with the mechanical pump. This also allows me to pressurize the line and try to see where the fuel is leaking from without starting the engine. So yes it dumps fuel all over once the pump gets going. Also the regulator was an uneducated attempt at an easy fix in my mind. Too much pressure, put in something to lower it...
Should I be replacing the fuel valve again? What part number would I search for to get an original one? The second rebuild was done by my buddies "carb guy" whom he relies on for all of the rigs he restores and works on. It's a reputable place with lots of expensive classics. Also I don't know what the acronym FLAPS stands for.
