Did you check to see if maybe the float has a pinhole in it, and has gas inside..?? If not that, if the little keeper spring, if it is still there where the pin that holds the float in place, can get in a position, when slipping the bowl back on, that will bind, and keep the float from completely rising. Just simply holding the float up, with fuel on, will let you know if the needle valve is completely shutting off the fuel flow. If holding the float up shuts the fuel off, then it's just a matter of adjustment, or, finding out what's binding the float, not letting it rise.
You can actually make a tool to "see" how much fuel is in the bowl, if you get it closer to the level it should be. The drain plug in the lower portion of the fuel bowl should be 1/8" npt. Go to a hardware and find a 1/8" npt barbed fitting, and screw in there. Also get about 12" to 18" of clear vinyl tubing. Slip it on the barbed end, and turn up, and tie off to something, to keep it upright. Turn on fuel, and the level of the fuel in the tubing, is the level in the carb. bowl. Of course, this won't help much, until you get the fuel flow stopped at a certain point. That's just for the final tweaking. Fuel level should be about 1/4" below the top of the fuel bowl.