47mm Cylinder Kit With Piston Kit For Yamaha Yz85 YZ80 Bike 2002-2014 1993-2001 16191253Introduction: A cylinder is where the piston and vales essentially "live". It's a cylindrical chamber that seats the piston. The piston is what is used to create the power of the engine. The valves open and close depending on what cycle the cylinder is on. On the intake stroke, the intake valve opens to allow air and fuel to be drawn into the cylinder. Feature: Condition: Brand New Warranty: 2 Year Specification Fit For: for Yamaha YZ85 2002 2018 for