Carb Issues - 1959 Firesweep 361 2bbl Carter

Tom,
This sounds like an excessive fuel pressure problem that's blowing the fuel through the needle and seat.
I have to assume that the float height and drop have been accurately adjusted during the multiple disassemblies although you may have to lower the float to exert more pressure on the seat needle. Most later rebuild kits use a rubber tipped needle for better fuel flow shut down.
I'd start by checking the fuel pressure out of the pump and if it's too high install a pressure regulator between the pump and carburetor. Those should be available through your local NAPA store.
It's possible that your new pump has a sticking pressure relief valve from a lot of shelf life.
I hope this has been helpful because carb swaps can be a nightmare because of linkage, choke and port differences.
Sounds like a good tech article for our De Soto Adventures magazine!
Wishing you great success,
Geoff

Thanks Geoff. That's definitely worth checking out. Think I'll have it checked out and go from there. I agree. A carb change would be a last ditch approach. Besides, I want to keep her as close to stock as possible. It's a mobile time capsule.

Yes, check fuel pump pressure. If it is greater than 7 pounds, you are putting too much pressure on the needle and seat. What did you do with the original fuel pump ? It may have been a better idea to rebuild the original. Many aftermarket fuel pumps put out too much pressure.

Also sounds like floats are incorrectly set. Is this the original Carter 2871S carb, or a replacement ? Why did you replace the floats ?

If you're tired of shade tree mechanics working on the carb, send it to Daytona Carburetor. They are experts and did a beautiful job on the WCFB 2210S on my 55 Desoto. Cost will be around 250-300 for a 2bbl. They guarantee their work.

Ron

Ron

Thanks Ron. Will keep that in mind as I dig into where the problem lies. It may be going off for a professional rebuild if the fuel pressure isn't the issue.

Tom,
Something struck me as I was mulling over recent issues when I should have been going to sleep.
Make sure that your gas cap is properly vented. Not only is it designed to let in air to fill the area displaced by used fuel, it is also vents air pressure created by an increase in temperature. sometimes they can act as a check valve and only let the air flow in one direction.
May your efforts be successful,
Geoff

Tom,

I had similar issues with my '55 Firedome with Carter 2 bbl. As mentioned here, the issue was too high of fuel pressure from a freshly rebuilt pump from an "expert" rebuilder of vintage fuel pumps. Apparently happens more often than it clearly should.

Good luck!

Mark

Hey, Tom-

No trouble with flooding on my '59 Sweep, but I had issues with hesitation for a couple years. I kept messing with the points and timing, but in the end it was a worn out accelerator pump. It fooled me because it would visually pump fuel into the venture, just not enough. The cup had worn down and allowed fuel to leak back around it.

Good luck on your carb repair. Our cars are much more enjoyable when we don't have to worry about stalling.

Glenn Colburn

Hi Tom,

I agree with all the very good advice given by others. The Carter BBD was a pretty reliable 2V carburetor. If after trying all those solutions, you still have trouble- there is one more thing you might want to check. Sometimes what looks like a carb problem is actually caused by your manifold heat control valve. Those will sometimes corrode stuck in the on position. When that happens, the manifold crossover will get too hot after the normal warm-up period causing fuel percolation in the carburetor and many of the symptoms you are complaining about. Just something else to look at.