I have some sweet mods on my 2008 CRF250. I just finished installing the R&D Power Bowl and Flex Jet. This mod makes the CRF run like an entirely new motorcycle. It makes it SUPER responsive, and really improves the low and mid range power. Revs great on top as well. A bit of work to install, but worth it. The Flex Jet is real nice as well. Makes fine tuning very easy. I can adjust the fuel mixture while sitting on the bike and its running.