686cc For Yamaha Raptor 660R 102 Big Bore Cylinder Piston Wristpin Gasket Kit 05 14640190Introduction: 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 Fitment: for Yamaha Raptor 660R 2001