NO, NO, Jorge. I have not meant to challenge you or your much appreciated advice. It is simply that I start from a position of complete ignorance on this matter and usually follow the advice of the people who produce the device in question. I do choose not to believe that the manufacturer (OS) would intentionally sacrifice his reputation on the altar or selling more engines and spares. I also believe that in this case more thought is required!!

I will study the article by Dar Zeelon (recommended by others also) in greater depth and will most likely follow that guidance. Thank you so very, very much for taking the time and having the patience to help me. I now understand more about this very important aspect of getting the best performance from an expensive part of a model airplane.

Frank Phelps
Grants Pass, Oregon