I bought an 04 NOS WR450 about a month ago. Took it out for a ride in stock form at Jones Creek, Washington. I was regretting my first fourstroke purchase. The bike stumbled, had marginal power, and had no tractor like properties that everyone talks about. I was kind've ticked and really wanted my YZ250 back even if I had to kickstart the darn thing on every hill I rode. Long story short, Bought a JD kit and installed it per directions. Took out snorkle. Installed GYTR baffle. Installed YZ throttle screw. Took the bike to Brown's Camp in Tillamook Forest yesterday and , this bike is a rocketship. I love the tractable power on long rocky uphill climbs. I couldn't kill the thing no matter how bad of rider I am. Nice long straight or an obstacle on the trail? A wack of the throttle carries the front end for a LOOOOONNNNNG way . The only thing that sucks is I know that tires and chains are going to be a very frequent purchase. It's not perfect yet. I still have a half throttle surge/stumble. I was going to look at the TPS. I've heard that sometimes these aren't adjusted properly. Anyone else have the same issue and what did you do to resolve it? My jetting setup is a stock jetting except for a 170 main, JD red needle on the fourth clip. Zip-Ty fuel screw at 1 3/4 turns. Altitude was 1500-2000 feet, low humidity and ~ 70 degrees. The exhaust note sounds pretty crisp in the offensive throttle positions hinting at a slight lean condition. I am going to fuss with the needle a bit. Maybe use the blue needle but I am curious to hear other stories about adjusting the TPS.