This sounds extra clattery to me but with nothing else to compare it to I really don't know. http://i3.photobucket.com/albums/y56/Jason77a/15C18FB1-4D9F-4690-9398-959794DA9AD5-806-000000AD4B45062C_zpsfc7be60c.mp4 2001 kx250 Runs fine, compression feels fine but haven't put a gauge on it. I thought maybe rod bearing but would you hear that all the time? It sounds fine when riding. Maybe it just needs a piston?