I purchased a OS 70 Surpass about four years ago and recently installed it on my GP 40 Cub. My question is in regards to proper idle adjustment. Basically, how do I do it correctly. Thank you.

To set the idle mixture, you have to have the engine broken-in at full throttle and leaned to just rich of maximum RPM. You then lean the engine and use the "pinch test" to determine the mixture. PInch the fuel line and let go. If the engine speeds up, you can lean the mixture. If it doesn't change or slows down, you can richen it a bit. Work with it until you get a good idle.