sounds like the flaots needs set, or the float valve is leaking.
the bottom end may be flooded now, which will prevent it from starting.
float help...
http://www.blasterforum.com/threads/float-heights-and-how-to-adjust-them.50565/
http://www.blasterforum.com/threads/easy-and-almost-free-way-to-stop-leaky-carbs.33335/
as for a flooded bottom end.
drain carb, petcock off to prevent more fuel from flowing in, remove exhaust from cylinder, hold throttle wide open and kick until your cousins leg hurts, LOL.
that should purge any excess fuel out of the bottom end, allowing the fuel/air mix to flow thru the bottom and up the transfers into the top end, as it should.