2002 CR250R Replaced the stock carb with Keihin PWK Air Striker. Fitting the new carb into the two boots required a little elbow grease and in the process it picked up a little debris. The float bowl overflowed so I sprayed the float needle and fixed the problem. Found out the I had to turn the idle screw in because out of the box it was turned all the way out, this meant that I could not start the engine with the throttle left closed, which I tried to do out of habit. I started with the throttle held open and then adjusted the idle screw. I know, backwards. I rejetted and set the needle clip for my altitude before the install and was fortunate to get great off idle response. Took several laps around my 4 acres and can really tell the difference in the feel of the two carbs. The Mikuni is offically retired from service.