Okay, I have searched EVERY thread for days it feels like and still have not found my answer for jetting without mods. So, I bought an '05 WR450 and a Dr. D complete exhaust system for it and have no clue what to set the baseline jetting at. The only mod I have made is the throttle stop screw and probably won't make any others. Dubach racing is telling me that the stock jetting is fine to run with the pipes, just adjust the pilot screw, but I know that can't be since it ran lean with the stock pipes. So I called Yamaha...three different dealers, three different opinions. I now have two places saying I HAVE to re-jet, and two saying I'm fine. I opened up the exhaust, my guess would be to re-jet. Can someone please recommend a baseline for me on my WR with only a pipe change? I will not be cutting the gray wire or removing the snorkel, just a high flow air filter. I will be running the bike in Northern California, sea level to about 4000 feet. The jetting database didn't really help since almost all are listed with full mods. Thanks for the input.