I am by no means an expert w/ these things, but by virtue of being low on the learning curve, I have been inside my son’s carb a few times recently.
Have you checked that the floats are shutting the fuel flow off? If the needle is not seating correctly perhaps the pump is just flooding fuel everywhere? If you take the fuel tank vent hose and blow into it, what happens? Does it get really hard to blow into or can you make fuel puke out? The floats should close the needle which would then make it hard to blow in the vent tube.