I think I may have found the problem. I pulled the cowl and noticed the back of the engine and carb spacer was wet looking. I wiped it off and smelled it and it wasn't gas so that means its from the crank case. I pulled the carb, carb spacer and found that was the source of the leak (right at the hole for the crank case pressure that actuates the fuel pump). I don't kow why this would cause a problem after eight minutes of flying though.

I was thinking that was the problem until I read the post from planeinsane and paulBK. I just realized the problem seemed to have started right around the time I put the smoke system on the plane. Guess where the smoke tank sits, right over top of both tank vent lines. The tank is not imploded at all but I bet tomorrow when I remove the smoke tank the problem will be fixed. I will let you know tomorrow, thanks for the input.