My zx6r is leaking gas from the #1 left carburetor. I've had the carbs cleaned, the floats are good, all lines are connected etc... Weird thing is, when the tank is not connected, the bike still runs for a few, but no gas is leaking at this time. When the tank is back on, the carburetor starts to leak again. All seals are tight, no cracks in bowl. HELP!!! PLEASE!!!! How can I fix this? what can be the problem?