Carburetor leaking fuel overflowing

[sjburk]

1967 GMC C1500 1/2 Ton I6 250ci
I replaced my accelerator pump yesterday on my Rochester B 1 barrel carb and when I put the carb back together the engine wouldn't start. I looked and must have bent the float because the measurements were way off so I fixed that and then when I put it on the engine will run for a minute or two but then fuel leaks out of the hole where the throttle hooks up to the carb and then runs up through a hole where it depresses the accelerator pump. I tried setting the float differently and even set it where it's always closed but it still overflows and leaks. I replaced the needle and seat and set it where it was always closed and when I blow through the gas intake where the hose from the fuel pump hooks up to the carb I can hardly get any air through. Since I've set the needle and seat and float to always be closed the engine will start real slow and steadily get faster as if I'm pressing the pedal until it finally starts leaking so I know it's slowly filling up with gas I just have no idea how because the float is all the way up and the needle and seat are closed but still I get way too much fuel in the carb. Does anyone know where else it could be leaking from or if I just need a new carburetor?

[Wrenchbender Ret]

It has to get by the needle & seat to flood like that. The floats may not be centered & hanging up on the side of the bowl.

[68gmsee]

Originally Posted by sjburk

1967 GMC C1500 1/2 Ton I6 250ci
.... when I blow through the gas intake where the hose from the fuel pump hooks up to the carb I can hardly get any air through. Since I've set the needle and seat and float to always be closed the engine will start real slow and steadily get faster as if I'm pressing the pedal until it finally starts leaking so I know it's slowly filling up with gas I just have no idea how because the float is all the way up and the needle and seat are closed but still I get way too much fuel in the carb. Does anyone know where else it could be leaking from or if I just need a new carburetor?

First, you shouldn't be able to blow even a little bit of air through unless you used pressurized air from a compressor. If you're able to blow even a slight amount, the seat and needle are not matching correctly. Seat or needle may be defective. That's why it runs and gains speed as more fuel is forced into the engine. Could be dangerous!

If you have access to a fuel pressure tester check for approximatley 4-6 psi from the pump.

[sjburk]

I see well I put back in the old needle and seat which were in there when it worked last and couldn't get any air through but still have the same issue. I adjust the float barely in one direction and it'll flood then just barely in the other (I can't hardly even see a difference) and then the engine won't stay running.