Controlling exhaust effects in CFS2

Got asked a question I can't answer. Maybe someone out there has the answer.
I use an exhaust effect on the YAS spitfires which is always "ON". I can't find any way of linking it to "engine start" so that it only shows when the engine is running. I guess in FS2004 there may be XML options but what about CFS2?????
I use an exhaust effect on the YAS spitfires which is always "ON". I can't find any way of linking it to "engine start" so that it only shows when the engine is running. I guess in FS2004 there may be XML options but what about CFS2?????