I agree that the the float mechanism is the likely culprit with fuel overflowing from the float bowl, which is why I'm perplexed. I've replaced every part and o-ring in the carb, except the float itself. I've checked the float height and confirmed it's right on. I tested the needle valve and seat seal by removing the carb and removing the float bowl, hooking up a hose to where the fuel flows into the carb, and blowing into the fuel intake while lifting the float until it seals (if that makes sense). It seems to be sealing perfectly. Plus, if excessive fuel was flowing from the carb into the engine, wouldn't my spark plug be fouled? But starting without choke, that would suggest way too much fuel, which would make sense. I just can't make any sense of it. Some symptoms point to being too rich, some seem to suggest too lean. I guess I'll take it all apart and check everything again. Thanks for your feedback slartidbartfast. I'd still appreciate any feedback you all might have. Thanks!