I have a 89 xr600r which I have owned briefly. I suspected some timing chain problems when I first got the bike because of some noise in the engine. I was riding yesterday when the engine died. After several attempts to crank it, the motor locked. I pulled the cylinder cover off today and the motor then unlocked and turned freely. The timing chain is fairly loose on the sprocket but turns with the engine. I suspect the timing has jumped. How do I check the tensioner and chain? I have the tensioner out and do not see a lot wrong. Can anyone help?