Next summer I plan to take a trail riding trip w/ a small tour operation that my friends have started. I think we're gunna be in the Aspen area. They might know this answer, but I thought I'd ask here also. I just bought a 08 YZ250F that I plan to use. My question is what do I have to do to make the exhaust legal? Do I have to go all out and get a new muffler, or will one of the available spark arrestor inserts for my stock muffler work? Thanks for any help!!