I just got the 450r and like it alot...nice power. I added a K & N filter, dynojet kit and cut a 4x6 box in my air box lid covered by metal mesh to keep the dirt out. my altitude is around 1300 here in KY. ..I like mid range power more than top end. The kit i have has about 10 jets to choose from...lowest is 108 highest 180. I installed the one the paper said to and couldnt tell much change...so does anyone have a nice setup they could share with me please.....mixture/air setting what ring the E clip is on and which jet would be best for my machine. Many Thanks

 

I have an '04 450R with a Hotcams Stage II, cut open airbox lid, Uni filter and an FMF Q2 slip on.
I went to a 185 main, a 50 pilot jet and I dropped the clip on the needle to the bottom.
I didn't change the air/fuel mixture screw and it runs great.
I had the same jet setup on it with just a 2" end cap in the stock muffler and cut open airbox lid. It was just a little rich.
So, if you didn't change the stock muffler I'g try the 180 main and maybe drop the clip to two up from the bottom position.