I just put D & D slip ons on my 1996 Monster 900. I also put a K & N filter and opened the intake box. I put 170 main jets in as well. This made a huge difference in the power output and sound of the bike, but I have a slight miss at low throttle opening. I think that it is most likely my pilot jets, as they are stock, and that seems to be the throttle position where pilot jets play a major role in fuel/air mixture. I currently have stock pilot jet (40). What size should I put in?