Yes. I know the idle mix is an air bleed and works opposite direction from other needles. I am very familiar with YS engines. I have been using them for years. They have always been a pain to tune. When the temperature changes you are tuning.

The darn things runs great when it's on it's side or on the bench. I have always had problems running them inverted. I am really tired of it. This is my last attempt to get it to work. If I can't I am going YS free.