I've always lived pretty close to sea level and I've never had to re-jet any of my bikes... so I'm afraid I can't be of much assistance. You might want to try posting your question in the main Thumper forum rather than this thread, as it may get more traffic and thus you may get an answer to your question quicker. Or I could google it for you: http://lmgtfy.com/?q=rejetting+a+2008+xt250
Originally Posted by artbone
I've got a 2008 XT250 and I live at 6500 ft. The bike seems really rich and the condition gets worse when I go over passes sometimes up to 8000 or 9000 ft. I pulled the air cleaner out to see if it made any difference and it made a noticeable difference. The bike ran much better.
When I look in the parts book they only list 1 jet size for XT250s. I've ordered a jet kit off ebay but don't really know what it consists of.
Does anyone have experience rejetting one of these carbs? Any suggestions on sizes, main jet only or main and pilot both? Lower the needle?
Someone give me some guidance here.