New 520 RS owner. As a die hard two stroke guy, I have a basic understanding of jetting, but as this is my first real 4 stroke, I'm a little confused as to the role of the fuel screw. The bike is running lean, and on a two stroke I would start with the main and go from there one circuit at a time, and that is my plan here, but I want to know exactly how the fuel screw comes into play. I have searched threads here and gotten an idea of the adjustment range in terms of how many turns out form lightly seated. So, my intention was to turn it to that point and experiment form there. There are two problems with this: first, I'd like to know exactly what throttle range(s) the fuel screw affects; and secondly, and more importantly, I am having difficulty in finding "lightly seated" because the remote screw is extremely hard to turn in either direction. I know this is probably a dumb question, and I have searched threads prior to posting this one, but I would rather ask a dumb question before I dive in and hopefully save myself some aggravation.