The principle of automobile engine and the factors affecting engine life generally install speed limiting plate on carburetor. If the speed limiting plate is removed prematurely, it will lead to abnormal noise, oil leakage, air leakage and power decline of the engine, and shorten the service life of the engine. 1. Selection of fuel and lubricating oil. The selection of fuel must comply with the brand specified for the vehicle. It is forbidden to use low brand fuel, otherwise the engine will produce knock, which will strongly impact the parts and increase the additional load of parts, so as to accelerate the wear of parts. The high temperature, high pressure and shock wave generated by detonation will also damage the lubricating oil film on the cylinder wall and deteriorate the lubrication of the parts. The test shows that the average wear of the upper cylinder with knock is more than twice that without knock. In addition, fuel with excessive impurities will also accelerate the wear and corrosion of parts. The selection of lubricating oil shall also meet the working needs of the engine. If the viscosity of the engine lubricating oil is low, the lubricating oil pressure is low and can not form oil film, resulting in boundary friction or dry friction; If the viscosity of the lubricating oil is too high, the fluidity is poor, which is not conducive to cold start. At the same time, the lubricating oil takes a long time to reach the lubricating part through the oil filter, which increases the starting wear. The lubricating oil shall be properly filled. When the oil level is too high, it will not only increase the movement resistance and reduce the power, but also make the lubricating oil rush into the cylinder for combustion, resulting in excessive carbon deposition; When there is too little lubricating oil, the oil pressure is low and it is difficult to form oil film, which will also cause dry friction or boundary friction, increase wear, produce abnormal noise of bearings, and even serious accidents such as cylinder pulling and Bush burning. 2. Cold start and cooling water temperature when the vehicle is cold started, especially in winter, preheating measures or cold shaking, slow turning and low-speed temperature rise shall be adopted as far as possible, and it is forbidden to slam the accelerator. When the engine is cold started, the viscosity of the lubricating oil is high, and it takes a long time to reach the lubricating part. Some data have proved that when the air temperature is - 15 ℃, the lubricating oil can flow to the connecting rod bearing and the moving pair on the cylinder head only after starting for 2min. During this period, if the accelerator is pressed sharply, the engine speed will rise rapidly, and dry friction will be formed at the parts where the lubricating oil does not reach, aggravating wear. When the engine temperature is too high, the lubricating oil becomes thin and can not form a lubricating oil film well, which will also increase the wear of parts and easily produce knock. However, the thermostat shall not be removed blindly due to high water temperature, so that the engine can work at low temperature for a long time, which will also cause excessive wear of the engine. 3. The road surface quality has a great impact on the exertion of vehicle speed, fuel consumption and wear. If the road surface is gravel or muddy, the driving resistance is constantly changing; When the resistance is large, the engine works under heavy load. At this time, the pressure in the cylinder increases and the wear intensifies. 4. In winter, due to the low viscosity of the lubricating oil, it is slow to enter the lubricating part, so that the dry friction time of the engine is long; In the extremely hot summer, when the ambient temperature is 40 ℃, the performance of electrical components will be seriously affected and the ignition system will not work normally; In addition, due to high temperature, the lubricating oil becomes thinner and the oil film is difficult to form, which increases the tendency of dry friction of the engine.
