You can try this for a quick try let the fuel tap off start the bike and run it till it runs out of fuel and as it's running gentley tap the float bowl with the handle of a screw driver,If there is dirt in the needle and seat it mat dislodge it and stop it flooding the carby if this dose work it may pay to clean the carby and also check the fuel in your tank make sure it not full of crap.A inline fuel filter is always good to have too.where did your fuel come from out of an old jery can or a clean container.
it could also be a hole in the float in the carby and it has sank but I would go with dirt first.
BIT