Maybe it just because I went and adjusted my valves myself and now im just over thinking things but a few months ago I did my first valve check/ adjustment on my 2010 set the intake to .004 and exhaust to .006 i swear the motor was quieter before i did this and the valves really didnt need adjustment still in spec but i figured mine as well set them perfect while i have them open. recently my buddy picked up a 2016 650 xt hear his motor run and its deffinetly quieter than mine maybe do to the body change and having more plastics blocking noise? I dont know now im considering opening up and checking again but I know its going to show there right. I have resently put the small washers on the bolts of my primary clutch to get rid of some of the slop the long bolts have to eliminate some of the clutch noise. got the bike with 13 plow miles on it last year never been on a trail till me now it has 600 trail miles from me. Any Thoughts?