SAME THING HAPPEN TO MINE IN THE DUNES, FOUND OUT HAD LOW COMPRESSION IN THAT FAILING CYLINDER. WENT HOME AND REDID THE TOP END, AFTER I HAD CHECKED THE NEEDLE CLIPS, THE CARB SLIDES, THE JETS, PLUGS FILTERS, BLAH BLAH BLAH... BIKE RUNS LIKE A CHAMP NOW. THIS WAS MY LAST RESORT.