Namura Top End Repair Kit STD NA-40006K fits 1993-1999 Yamaha Kodiak 400 YFM400FW 4X4 / 2000-2002, 2004 Yamaha BIG Bear 400 YFM400 / 2000-2002, 2004-2006 Yamaha BIG Bear 400 YFM400F 4X4 / 2003 Yamaha BIG Bear 400 YFM400FW 4X4, BIG Bear 400 YFM400N

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