One is the valve phase off. The opening and closing time of the intake and exhaust mechanisms calculated based on the top and bottom dead center of the piston is called the valve phase. The opening and closing timing of intake and exhaust valves is not at the piston stop point. Instead, it is opened early and closed relative to the dead point, and its purpose is to achieve sufficient intake air and clean exhaust to improve the power and economic performance of the internal combustion engine. If the gas phase is not correct, the cylinder will have insufficient intake and exhaust gas. Incomplete combustion of fuel, declining power and economic performance, difficulty in starting, or even starting. When the valve is out of phase in the repair process, the middle gear may be removed to rotate the crankshaft to the top dead center of the piston. The camshaft rotates to the fully closed positions of the intake and exhaust valves, and the fuel injection pump basically terminates the position. Then install the medium gear and press the direction of rotation of the flywheel to check whether the top dead center and oil supply time mark on the flywheel is opposite to the mark on the machine body. Then adjust the valve clearance according to the regulations to achieve easy start. Power is enough to work without smoke. The second is cylinder pressure off. Cylinder pressure has a great influence on the power and economy of the engine. If the cylinder pressure is insufficient, the pressure and temperature of the compressed gas in the cylinder cannot meet the requirements. The fuel mixing and combustion process in the spray cylinder is slow and the combustion is incomplete, which can cause the engine to be hard to start, black smoke, power drop, and fuel consumption increase. In order to ensure that there is sufficient pressure in the cylinder, during the repair process, it should be ensured that: the cylinder sleeve and the piston group are matched with each other, and the clearance meets the requirements. The edge clearance, opening clearance and elasticity of the piston ring meet the requirements; the sealing of the valve and the valve seat ring Meet the standard requirements; cylinder gaskets, fuel injectors or gaskets at the front of the spark plugs are intact. otherwise. Relevant parts should be repaired or replaced until the cylinder pressure reaches the standard value. The third is compression volume off. The compression volume in the cylinder affects the compression ratio, and the compression ratio also has a great influence on the dynamics and economy of the engine. In order to ensure that there is enough compression ratio, the clearances of the main bearings (watts), connecting rod bearings (tiles), connecting rod bushings and piston pins should be carefully checked during the repair process. Excess tolerances must not be exceeded. The parts should be replaced; check valve subsidence should be checked, if exceeds the specified value, valve seats and valves should be replaced and trimmed; in addition, check the thickness of the cylinder head gasket and other parts that affect the compression ratio. The fourth is fuel injection quality. Spraying the fuel atomization quality and fuel injection pressure in the cylinder. It also affects the start of the engine as well as its power and economy. Therefore, the fuel supply system should be carefully checked and adjusted during the repair process. The fifth is the "three nets" pass. Air, diesel, Unclean oil filter and poor technical condition will directly cause early wear and tear of the relevant parts and shorten the service life of the machine. Therefore, during the repair process, air, diesel oil, and oil filters must be carefully inspected, cleaned, or replaced. In the process of use, regular maintenance must be performed to maintain the “three nets†of air, diesel, and oil filters. Sixth, it is worn off. After the engine is overhauled or repaired, the surface of its main mating parts is not ideal. In this case, if the heavy load is put into operation immediately, relevant parts will be worn early. Therefore, after the engine has been repaired, conditions should be followed by cold running-in, unconditionally, no-load, small-throttle running-in can be performed, and then the load running-in can be performed according to the provisions of the running-in procedure, and then put into normal use. Agrostis Stolonifera,Astragalus Sinicus,Vicia Villosa,Agropyron Cristatum Chengdu Lv Mu Tian Xia Agricultural Technology Co. LTD , http://www.cdlmtx.com