2.5 turns out 1 up on the pilot and 2 up on the main and tune it from there. there is no magic number or short cut. you have to make a change, run it, and check the plug. adjust and do it again until its right. order some extended air mix screws, makes mine tuning much easier. the closest thing to a short cut is the sigma jet kits. go to their web page. enter your machine elevation and mods and they custom build you a kit that will get you in the ball park. then its just a matter of needle adjustment and air mix screws