Thats a +3mm BigBore Kit and will turn your ATV into 468cc ('04-05 models) or 478cc ('06-13 models)!
Complete kit with gaskets, cylinder, piston, rings, pin and clips
Compression ratio: 12.0:1
-Ready-to-install, direct bolt-on cylinders require no re-plating and look virtually identical to the OEM cylinders
-Cylinder kits include matched Vertex pistons to ensure longevity, performance and reduced engine noise
-Nickel Silicon Carbide (Nikasil) plated for long life
-Honed to exact size for easy piston installation
-Big bore cylinders do not require machine work (unless noted)
-Made in the U.S.A.
-Replaces Yamaha OEM cylinder 5TA-11311-12-00