1. Fuel supply system The function of the gasoline engine fuel supply system is to prepare a certain amount and concentration of mixed gas according to the requirements of the engine, supply it to the cylinder, and discharge the burned exhaust gas from the cylinder to the atmosphere; diesel fuel supply system Its function is to supply diesel and air into the cylinders, form a mixture in the combustion chamber and burn, and finally discharge the burned exhaust gas.

2. Lubrication system The function of the lubrication system is to deliver a certain amount of clean lubricating oil to the surface of the relative moving parts to achieve liquid friction, reduce friction resistance, and reduce the wear of parts. And clean and cool the surface of the part. The lubrication system usually consists of a lubricating oil passage, an oil pump, an oil filter, and some valves.

3. Cooling system The function of the cooling system is to dissipate part of the heat absorbed by the heated parts in time to ensure that the engine works at the most suitable temperature. The cooling system of a water-cooled engine is usually composed of a cooling water jacket, a water pump, a fan, a water tank, and a thermostat.

4. Ignition system In a gasoline engine, the combustible mixture in the cylinder is ignited by electric spark. For this reason, a spark plug is installed on the cylinder head of the gasoline engine, and the head of the spark plug extends into the combustion chamber. All equipment that can generate electric sparks between the spark plug electrodes on time is called the ignition system. The ignition system usually consists of a battery, a generator, a distributor, an ignition coil, and a spark plug.

5. For the starting system to make the engine transition from a static state to a working state, the crankshaft of the engine must first be rotated by an external force to make the piston move back and forth. The combustible mixture in the cylinder burns and expands to work, pushing the piston down to rotate the crankshaft. The engine can run on its own, and the work cycle can proceed automatically.