Introduction: Cylinder (cylinder) refers to the internal combustion engine or external combustion engine, the piston in which the piston is allowed to reciprocate up and down. In a multi-cylinder engine, the cylinders are usually arranged side by side in a row, which is called a cylinder bank (Bank), for example, a V-arranged engine is composed of two sets of cylinder banks in a V shape. Multiple or one cylinder bank constitutes the cylinder block. The piston is a hollow cylinder that slides in the cylinder, and the outer diameter of the piston is approximately equal to the inner diameter of the cylinder. The function is to change the volume enclosed by the cylinder, or to transmit the pressure exerted by the fluid in the cylinder. The piston is in contact with the burning high-pressure gas, bears the impact pressure when the mixture explodes, and reciprocates in the cylinder at a very high speed, while rubbing against the cylinder wall in rapid relative motion. Fit For: for Yamaha