The float can certainly cause trouble, usually the tiny plunger spring in the needle gets weak and does not cut off the fuel when the float level setting is reached but allows a bit more fuel in the bowl before it shuts down, best way to tell if your fuel level is set right is to bench fill the carbs with a funnel and fuel line then remove the fuel line so no extra gas get`s in then measure each bowls fuel by removing the fuel bowl drain screw and draining into a beaker or other measuring container that has CC`s marked on it..think I found they should have 52CC`s of fuel each bowl give or take 1 CC.
If you are unsure about the float needles replace them all, I was surprised at how weak all 8 used floats needle springs were when I compared them to new ones, rubber looked great but needle springs were weak, replacement took care of my intermittent flooding issue for good.
By the way the first carb you drain will have a few extra CC`s of fuel due to the extra fuel in the fill tube, I check mine 2 or 3 times and make the second drain another carb first to check all of them thoroughly.
