Does it leak gas when "flooding"? Or does it just go too rich. One
possibility is you have a float with a leak in it. This will make the
carb run rich and even leak due to overflow. Just an idea.

Just get a mechanic and have him take it apart. There is some FAA
thing, but if you send it out for overhaul, theres no biggie. He can
take it apart, just cant put it back together. Some mechanics can put
them back together though. I dunno, all that FAA stuff but there is an
issue there. Some mechanics work on carbs and some don't. Find one that
will. Have him take the bottom off the carb, check the workings out,
find out whats wrong and fix it. Ask around.

I know what you mean about wanting to find the problem. That way you
make sure it gets fixed. Otherwise its just some kid in a shop who
could care less.