This is a new build and I am breaking in the engine. As you can see from the photo, I'm using the standard stock tensioner. There is little play in the chain which is a #41 that replaced the stock 415. http://i4.photobucket.com/albums/y109/stilldoc/photo-11.jpg Everything seems to be in line. There is very little wobble of the sprocket and it seems well centered. Despite that, the chain shakes violently, especially at low rpm's. I've had no problems with it coming off the sprocket. I guess this is a newbie "Is this normal?" post. Thanks for your help. I could post a video if needed.