Iactually tried the os "F" plug and it did not work so well. Ibelieve it overheated since it has a nose that stick out into the combustion chamber. That is one difference between gas and glow engines; the temperature. Either that or the fact that it was hitting the piston. Since the os "F"plugs were a little more $, Idecided to make this work for less $.

Idid get the ryobi 31cc to run with my adapter, but it was not optimum, Ithink Iwill tackle the ryobi next. The other neat advantage my adapter has is that it increases the compression ratio since it is displacing more volume than the spark plug it replaces without any machining. Iwill try to post some prop data to support this.