You guys are scaring me. Never had a propane fire but I did do the brake clean on the motor and then the plug wire jumped a spark to the block. The motor burst into flames. I freaked, yelled FIRE, put it out with a extinguisher, then looked around and no one had even noticed. Cleaned up the extinguisher powder and the customer never knew what happened.
The only thing I can suggest about the Yale is ignition timing. I've noticed that Nissan H20's stumble as you throttle them if the timing is off.