94 Carb Question:

[40ford]

I installed a new carburetor from Dennis Carpenter on my truck.(1952 F-1 flathead V8 stock).The truck runs very smooth with no issues except when I stop engine and it sits for a short time I notice the smell of gas and truck is flooded and hard to crank.I have carb back off and what should I check?I checked float level and looks like about 1 and 10/32 inches.

[Chuck41]

I had the same problem. The bowl was overflowing into the throat after shutting off the engine, making hot starts very hard after sitting for a while. Could be sticky or non-seating needle valve, float level too high, or fuel pump pressure too high so that the residual pressure after engine-off overcomes the needle valve. My problem was float level. I believe the spec on the 94 is 1-9/32 height and 1-17/32 drop (but have also seen 1-11/32 and 1-7/16).

[Seth Swoboda]

If it's not your float sticking, I would suspect a leaking power valve. You can take the carbureator off the engine, place it on a shop rag with the bowl full overnight. You will be able to tell if the power valve is leaking.

[38 coupe]

I habitually lower the float approximately 1/4 inch compared to factory specification. I find this compensates for the alcohol gas we get today and prevents hot fuel percolation down the intake.

[tubman]

Originally Posted by 38 coupe

I habitually lower the float approximately 1/4 inch compared to factory specification. I find this compensates for the alcohol gas we get today and prevents hot fuel percolation down the intake.

A full quarter inch? I'm not doubting you, but that seems like a lot to me.

[Mart]

Sponsored Links (Register now to hide all advertisements)

New carb from dennis carpenter? So is this a copy of a 94 or a 94?

If a copy then hard to apply any of the usual 94 type lessons learnt.

[nickthebandit]

Contact Charlie NY, formerly here on The Ford Barn. He is the go to person for 94 type carburetors. 716-662-9159.

[OhioRick]

Are you running an electric fuel pump?
Check your fuel pressure regardless of what you are using.
Should be no more than 2-1/2.
Many times the residual pressure after shutoff will cause this issue.

[38 coupe]

Originally Posted by tubman

A full quarter inch? I'm not doubting you, but that seems like a lot to me.

Yes, a quarter inch, and yes it is a lot. I run the cheap 87 octane gasoline available in Texas and expect to be able to hot start my cars during the summer.

Long story: I started doing this in 2007 after going through the Stromberg 97 on the 37 sedan I shared with my dad. I was at a friend's house and we went through all my normal carburetor efforts (disassembly, cleaning, inspection, reassembly, measuring the float, etc.) with the result that the car ran great. However, after turning off the engine and waiting approximately a minute we watched gas flowing down the throat of the carburetor due to heat soak. My friend pointed out I could take the top off the carburetor without disturbing the float and see where the fuel level was. Off came the carburetor top and we found the fuel level too high. We soaked up some fuel, lowered the float, and used the starter to spin the engine long enough for the fuel pump to fill the carburetor bowl to its resting level. Too much fuel again. We repeated the process several times resulting in the float being dramatically down from spec, but with the fuel level now correct. The car got driven 10,000 miles in the next decade with the float like that and excellent performance.

I have only had to raise a float once back up a little bit once, on a vehicle that could empty the float bowl during hard acceleration.

The easiest carburetors to see if your float setting is correct are the 52 and later 6 cylinders with the "visiflow" units featuring a glass float chamber cover. As with V8 carburetors, setting the float way down results in fuel at the correct level.