I will admit I just got in my first decent ride on my 02 650L I picked up a few weeks ago. A short list of mods. Bike has 2400 miles, de smogged, ISDE? supertrapp pipe, de snorkeled,Uni filter, valves just checked, ?? Dyno jet kit installed by PO. I have no idea what the kit usually supplies or whats in it but I get quite a bit of back firing on 0 throttle decell. Theres a pretty good flat spot/hesitation on inital throttle/low rpm. Ive never had much luck with jet kits, I prefer my own doings but what done is done. Once its goin it runs pretty good It seems from reading here. 2nd gear wheelies are no problem and Im 240 lbs. Are these carbs pumpers? and what is the normal idle mix screw setting? I have mine at 2 3/4 open. If im not mistaken anything more than 2.5 out says bigger pilot? Are the jet kits bad news? Thanks much for any help.