Re: 66cc Bike Engine Caught On FIRE!!!
The only thing that could cause that is riding your bike until the motor was at peak temps and the fuel line was bumped off of the filter or petcock and spilled directly on the head, jug and/or exhaust. Heats it, vapors are there, they ignite, melts the fuel line, spill out everywhere on fire.
I don't buy the "I got my camera, the fire extinguisher didn't work" though. I don't see any fire extinguisher retardant anywhere on the bike.