take the carb out. use a 17mm wrench and take the screw out of the bottom, gas WILL come out so have it in a pan. then once its drained, i belive its an 8mm socket to take the main jet out. it will be right there in them iddle of that hole were the cap was. but use the jetting 101 to figure out whats the right jet. if your all stock with a new pipe, probably a 260 or 270 if you have ur airbox lid off.