Hi, My 2002 WR426 jetting is completely stock and the only mods I've made to the bike are removing the airbox lid, cutting the gray wire and trimming the throttle stop. I typically ride the bike at Ocotillo Wells but will probably also try the track at Lake Elsinore soon. Are there any jetting changes I can make for the bike to be more responsive. I'm not interested in YZ timing because I don't want to give up the bike's smooth low end power but I'm interested in making the mid range more responsive and getting the bike to pull better in fourth gear. Would installing a stock YZ needle jet and main jet make a big difference without causing any adverse side effects???