The front seal on a two stroke glow engine is made between the crankshaft and the crankcase, not the bearing as most people think, it could be that either the crank or case is out of tolerance causing the fuel to leak out, but most of the time a leak here will create an engine that won't turn off as it is drawing air in. Under normal circumstances there should be a vacuum present there as the engine is "sucking" the fuel mixture from the carb, could it be possible there is something blocking your exhaust causing some internal pressure in your engine ? or maybe the piston is scored and blowing pressure inside your engine.

Also does the fuel leak out as it's running? if it is just when you are starting the engine you maybe heavily over priming it.

Also back to the head question, has anyone seen a Magnum .52XLS with the head he has on or have they all been the blue head. I think this engine may have been modified.