Here is how I have always done it, well first it depends on how many needles you have, if only 2 back them both out until they are flush with their housing, then turn them in 1 1/2 turns, that is going to be extremely rich, it is a safe pace to start with on any engine, if you have 3 needles, don't adjust the 1 on the carb slide where the servo connects, until the other 2 are tuned properly, remember richer is better, keeps the engine cooler.