The body is composed of a cylinder head, a cylinder block and a crankcase. The cylinder head is made of aluminum alloy casting with radiating fins. 

 

The new four-stroke motorcycle/motorbike engine adopts overhead valves, chain transmission, and overhead camshaft structures. The cylinder block material is mostly bimetal (abrasion-resistant cast iron cylinder liner cast aluminum heat sink) to get better heat dissipation effect. 

 

Some motorcycles/scooters use wear-resistant cast iron cylinders, In some small mopeds, the inner wall of the aluminum alloy cylinder is plated with 0.15 mm hard The structure of the chromium layer. The crankcase is made of aluminum alloy die-casting by combining the left and right boxes. Some motorcycles/motos add buffer blocks between the heat dissipation signs to suppress the noise caused by the vibration of the heat sink.