Namura TOP END REBUILD KIT NA-40009-BHK fits 2009-2015 Yamaha YFZ450R, YFZ450RSE Special Edition / 2010-2011 Yamaha YFZ450X / 2010 Yamaha YFZ450X Bill Balance Edition / 2011 Yamaha YFZ450XSE 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