Graves Motorsports is a motorcycle racing and parts manufacturer providing racers and customers with exceptional products developed from the many Graves Motorsports championship winning race teams. Graves Motorsports High Precision Cam Chain Tensioner. Professionally developed under strict guidelines for use in the Graves Yamaha factory race bikes. Note: You will need a replacement timing cover gasket and cam chain tensioner gasket from your local dealer (both sold separately). Cost vs Quality: Compare this product to the competition's product and the cost. Graves Product: Adjustment shaft is made of aerospace-quality steel machined to a 1.0 threads per millimeter allowing the tuner to adjust the tension on the chain to an exact specification = less friction and consistent cam timing = more power.