Wiseco Yamaha YFM660 Grizzly/Rhino 9.91 (4966M10000) Piston Kit

Premium materials produce the best sealing technology available exceeding O.E.M. standards. 2-Stroke: Wiseco top end gasket kit; Dedicated forging; Superior strength/weight ratio utilizing Aerospace alloy; Race-proven designs; Chosen by top race teams, in all forms of racing; CNC machined; Optimal cam shape and profile for peak HP and service life; Premium top end needle bearing; Precision-machined, highest-quality materials for strength and reduced friction; High-performance ring set; Extended life and sustained power; Highest-quality alloy pin; Consistently true and durable. 4-Stroke: Wiseco top end gasket kit; Premium materials produce the best sealing technology available, exceeding O.E.M. standards; Dedicated forging; Superior strength/weight ratio utilizing Aerospace alloy; Dome design; Improved flame travel; Chrome plated piston pin; Horizontal slot pin oiling; Reduced friction/scuff resistant; Pressure seal groove; Maximum ring seal; Armor Glide Skirt-Coated available for select models; Dedicated Rings; Maximum compression and oil control.