2001 Suzuki gz250

Question

I bought a used 2001 Suzuki gz250, it was not leaking gas at all when I bought it, but for some reason now it’s a continuous stream from the overflow,when I’m running the bike or if the gas is turned on when it’s idling, I’ve put all new screws and a new drain plug in the carb, and the floats not sticking, plus the petcock shuts off the gas correctly, so I’m confused as to why it’s leaking, I’m losing my mind and money on gas over this, can someone please help!!!