bubble on carb should be full so i wouldnt worry about that. check the gascap insides. your liner may have a big hole. you will get a little bit of dribble out of the vent holes in the gas cap, but anymore than a lil dribble would tell me the cap guts are buggered somehow.
Just another idea. Pressure in the tank can be the cause.
The breather tube was the release for the pressure and thats could be why it was pouring out. You may of filled the tank too full this would not allow the air to escape correctly out the breather tube before the fuel got in the way and shot out, or your pressure exhaust line is too deep in the tank and not up top where the fumes are.
My MT will also loose the bubble in the carb when the tank gets low or has too much pressure in it, but the motor runs much better at least it does with mine. With my MT it doesn't have the exhaust like the Leopard or DTFH and allways has pressure when its hot, so I have to stop and crack it once in a while - Soon to be vented.