I have a 99 YZ400F that is basically stock and has fairly low hours. Today as I was starting it I noticed that it felt like the compression release would not "release" and I could kick it over without the lever actuated (I would never have wanted to/could push it past TDC without the CR lever before). It also made it run poorly at moderate RPM's (I was hesitant to rev it naturally). I adjusted the CR cable and that didn't really seem to help. The actuator arm presses against the engine block stop so it is going out as far as possible from what I can tell I then checked my sparkplug to see if it was loose and it was somewhat loose but after tightening it appropriately it still exhibits this problem. I just bought the bike and have not had the valves checked but it has been running fine with plenty of compression and had compression during the first few kicks today so the onset was very sudden. Also, there are no unusual noises in the engine. Anyone have any ideas as to what could be the problem?