Ancient Earthbird tiller carb floods

I have an inherited Earthbird tiller, has to be over 25 years old. I love it. No idea what the history is, nor anything about the company. Has a B & S engine with a very simple carb that I just CANNOT stop from flooding. I've done a complete carb rebuild, and think I have adjusted the float properly (also has no leaks). I do not know how to adjust the main jet, but with the flooding I can't even get that far yet. For now, the main jet is snugged up semi tight (could that be a problem?). New needle & seat, cleaned, flushed, the works. I'm stumped. When I have it reassembled I can hear the float moving freely with a gentle shake. Starts with a little priming, runs fine for about 30-40 seconds, then fuel drips slowly from the air cleaner screw hole. What am I missing?

 

Engine size type and model #'s would be very helpfull.
In general ,short of an internal crack in the carb body, the only thing that should cause that leak is the needle and or seat. Possibly the needle installed improperly or it fell off the float, the seat not installed correctly or completely. If your main jet is on the bottom of the bowl, 1 1/2 turns CCW from lightly seated should get u started and adjust from there.

 

Correct, the seat may be the problem here. It sounds like you have the old updraft carburetor. This has a brass press-in seat, correct? If so, try replacing it again, but smear a thin coat of jb weld around the seat before installing it so that it will seal against the carb body. You might never be able to remove it again, but there probably won't ever be a need to. Let it cure several hours before putting the carb back on.

Oh...remove the float, hold it to your ear, and shake it. If you hear a sloshing sound like gas in the float, this is why the engine is flooding. Replace the float if that's the case.