Just recently got my 2000 400ex, love it! I ride in Washington and wondered if anyone has any thoughts on tires. I mostly ride trails, many covered in mud, some logging roads. Also, anyone play with exhaust yet? Fmf,white bros, Big gun? A friend just put in a FMF power core4 with K$N filter. Snappier throttle response,more low end, some gain in top end,not much. No jetting change at this time. Any help would be appreciated.