Every Classic Motorcycle Manufacturers hopes that the service life of their motorcycle is as long as possible. The service life of a motorcycle is calculated by the mileage of the motorcycle overhaul. The overhaul mileage of domestic motorcycles is generally between 50,000 kilometers and 100,000 kilometers, and the upper limit may be reached when used reasonably, and the lower limit may not be reached when used unreasonably. It can be seen that use factors have a great impact on the life of motorcycles. The main signs of motorcycle overhaul mileage are the wear of the cylinder surface and the wear of the crankshaft, of which the wear of the cylinder surface is the most important. When the surface of the cylinder body is worn, the gap between the piston and the cylinder body increases, causing the knocking sound between the piston and the cylinder body and causing leakage. At this time, the fuel consumption of the motorcycle rises sharply, and the power of the mechanical efficiency drops rapidly. , Must be overhauled. The main item of the overhaul is to boring the cylinder to replace the piston to restore the normal gap between the piston and the cylinder. Domestic motorcycles are generally 0.05 mm to 0.07 mm (referring to the gap value between the piston skirt and the cylinder block). How to avoid the abrasion of the cylinder surface has become a key issue in prolonging the life of the motorcycle. This article explains what measures can be taken in the use of motorcycles to avoid the wear of the cylinder body as follows.