Originally Posted by Venice Motor Bikes
The fuel comming from the exaust pipe can't be comming from the carb.. (The whole crank case would have to fill up first, & even then, the intake port is lower than the exaust.)
The fuel comming from the pipe is probably just unburnt fuel sitting in the pipe.
actually, depends on the position of the piston. if the piston is right at the bottom of the intake port, then the fuel can fill up a small portion of the cylinder and flow right into your exhaust port. happened to me once when my petcock failed.
most likely cause is unburnt fuel from a rich mixture, though, like Venice said, unless it's a lot of fuel.