Just got back from riding with my budds 650R. Hate to say it, but an uncorked(hrc) 650R still beats my 650L. My 650 has a stage 1 cam, xr's only carb tweaks, 10.5 comp piston, air box mods, Big Gun header and evo X silencer, valve job, and a rod kit. All dialed in. 650R still beats me pretty good(1 bike length). The 650L still feels slower than my 600R with lighter mods, but have not raced yet. Looks like it is time to find a PLATED 650R to build!!!!!!!