Namura TOP END REPAIR KIT STD NA-40010K fits 2002-2004 Yamaha Grizzly 660 YFM660F 4X4 / 2004-2007 Yamaha RHINO 660 YXR660FA 4X4 / 2005-2006 Yamaha Grizzly 660 YFM660FA 4X4 / 2006 Yamaha RHINO 660 YXR660FASE 4X4 Special Edition

Top End kit includes: piston, rings, wrist pin, clips, top end bearing, and gasket kitMOS2 (Teflon/Molybdenum) Coated Skirts A rolled on application process provides a bond that is 10 times stronger than other spray on coatings. Benefits include increased heat transfer, reduced friction and helping to eliminate cold seizuresMachined Smooth Heads Reflects combustion heat and reduces carbon buildup, protecting the top of the piston. Some tests have shown this feature can increase horsepower and fuel economy by up to 6%Anodized Domes Increases heat resistance and durability; pistons with anodized domes are 75% stronger than non-anodized pistonsHypereutectic Casting Process Provides higher silicon content for reduced expansion rates and additional wear resistance; it also has an ability to withstand higher cylinder temperatures