Namura Top-End Repair Kit NX-40048-CK fits 2014-2017 Yamaha YZ450F / 2016-2019 Yamaha WR450F, YZ450FX

MOS 2 (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 temperaturesTop End kit includes: piston, rings, wrist pin, clips, top end bearing, and gasket kit