OK, I purchased a DSP race pipe, I also purchased the JD kit. I have a 99 WR400 in excellent shape. The pipe manufacturer says for a yz 400 to use a 180 main and a 48 pilot, there were no WR recommended jeting specs. 180 sounds to big? Did the yz400 use the same carb? Well the only jet close that came in to JD bigger was a 170. So I tried to run a 170 with the 45 pilot and the JD blue at #4. It will not idle. To start the bike I would have to choke the bike and hold the throttle all the way open. If I let the throttle all the way off well riding it just stalls dead. I bought 2 pilots from from a shop and they looked the same but were to big. It was running perfect before the jet and pipe change. I think I need a bigger pilot jet to get it to idle. Anyone have any thoughts ?Anyone know a place online to buy jets for that carb? ok I found plenty of pepple selling pitot jets online but non list the WR as a model Can anyone tell me the part number for the pilot jet used in the 99 wr? Thanks for your time.