Hey guys, Last weekend I picked up a 2002 YZ250F for a pretty good deal. This is my first dirt bike in 15 years. When I bought it, the guy started it for me as I was unable to...lol. No I'm not a little guy either. It wasn't hard to kick over but it just took many tries. Anywho, I brought it home. Yesterday I replaced the air filter, installed an external fuel screw and changed the oil. I checked the valve clearances and four were out of spec. (both exhaust, 2 intake) The ones that were out of spec were all too tight. So I re-shimmed them all with in spec and put everything back together. Once it was all put back together, it was extremely hard to kick over, I weight 220# and I could stand on the kick starter. So I pulled the valve cover back off, check the timing and that was perfect. All valves still in spec. Checked the kick starter again, still hard to kick over. Now I put all the old shims back in. It was easier to kick over again. (not too easy, still had compression) Any ideas whats going on with this?