If the float was stuck on the carb and the fuel pump kept pumping gas, it would run into the cylinders and begin over flowing the crankcase. I remember MANY years ago in auto shop class each "lab team" had to completely disassemble an engine we had on a stand, hone the cylinders, fully reassemble and the engine had to run for us to pass. Well our engine was a V8 from a 1957 Pontiac. They didn't have enough $$$ for us to get new piston rings, and after all the honing and assembly/reassembly well let's just say the engine was "loose". Also they would not give us new parts for the fuel systems so the poor Carter AFB was loose and leaky. Well in the process of getting it started fuel had gone past the rings and into the crank case. We got it running but burning fuel worked past the rings into the crank case and the engine literally turned into a fire ball. Burned off my eyebrows, singed my hair, scorched my face and I think soiled my pants
anyway let's just say it was "interesting"