I just changed my jetting for the first time, Once I figured out that I could just rotate the carb it was really easy! Anyway, I went from Stock jetting (162,42,4th) to 158,40,3rd. I ride at 4k-6k ft. Problem is now its really hard to start, it always makes the noise like its about to fire, but only does when I fidddle back and forth with the choke out/in. Also, it seems to backfire on certain occasions. Should I go back to stock jetting? and leave the needle at 3rd position? I had a stumble/bog when shifting gears which led me to redo the jetting to begin with. But its just too hard to start now, why?