I'm riding a '00 WR400F YZ, timed, UNI w/cover off and stock exhaust w/o baffle. I ride in NM @ 5,000-6,000 ft. I'm currently running PJ=42, MJ=170, DTM needle #2 from top Air 1-3/4 turns. This was recommended by the Yamaha dealer. Bike seems to run rich at mid throttle. I'm thinkin' about changin to the DVR needle #4 and PJ=45. Bike runs okay, but a little sluggish in the low end and transition to wide-open isn't crisp. Any suggestions from the experts?