I've done the research, and even in the most consise explanations about adjusting the fuel screw, the words "fast idle" are mentioned. What the heck is a fast idle? Without a tachometer or the ear of a veteran mechanic, how does one determine when to stop turning the idle screw once a fast idle has been reached? Also, does anyone have any pointers about installing the Zip Ty fuel screw on the FCR carb for the WR 450? This is the carb that has a plug in the fuel screw opening. What is the proper way to remove that plug?