Hey guys, I haven't been on WD for a long time, but yes, I have an XR400R. Had it for about 10 years. Its 2004 model, and I've fitted a 1mm os wiseco 11:1 piston, std carb with 145 main jet, aftermarket header pipe (can't see what brand), CRF450 tail pipe, aftermarket CDI, fat bars, I widened...