I have an '04 wr450 done in SM gear. 17" rims with I believe a 40 tooth rear sprocket. Motor is stock w/gytr exhuast baffle. gray wire cut and the air box oppend up a bit. I believe the carb is still stock with just a quick adjust FS. Plug looks good... pipe gets a little carbon at tip over time, so I would say I'm on the rich side of things but not overly. While on the road holding a steady speed say in 5th gear at low RPM's (4000-5000) I get, a for the lack of the correct term... bucking.... In lower gears at the same rpm's it does not seam to be as pronounced. This correlatets to the 45-50mph range which is where I seam to spend alot of time. Is this in the realm of jetting or is it more of a mapping issue? Even if it is a mapping issue are there settings to minimize the issue? Thanks for any help offered!!!!