Do you know for sure you are getting spark? This almost sounds like an ignition problem to me.
If the float had a hole in it, it would be full of fuel, and if the needle was stuck open I would think that the carb would overflow with fuel and spill into the engine. If that is the case, you would have a lot of fuel in the oil or at least on top of the piston. If you tried to start it in that case it would hydro-lock and likely bend a rod. Next time you try to start it, pull the plug, try turning it over and see if fuel shoots out of the spark plug hole.
Did you check the float height adjustment? It should be about 1/2" or level with the flat part on the aluminum body where the cover mounts. You can check if the needle is seating properly by blowing into the inlet (make sure its clean) and moving the float up and down to see where in the travel it closes (blocks you from blowing air). If it never closes or closes way too low, then you have your answer.
I just had mine apart but never tried to remove the float, so I dont know what the pin looks like. Sorry. But I found a float kit on ebay and the pin just looks straight on that end. I dont know why it would be peened over...