小四轮拖拉机是我国乡村的主要生产运输工具,尤其是实行联产承包责任制以后,小四轮拖拉机已走进了农村的千家万户;但随着拖拉机的使用,动力性、经济性和使用性都在逐渐下降,特别是由于机器本身的磨损,气缸内的压缩比逐渐减小,起动性能也随之下降,使得起动困难。导致这种起动困难的主要原因是缸筒活塞 Small four-wheel tractor is the country’s main production and transport vehicles, especially after the implementation of the system of contract responsibility system, small four-wheel tractors have entered the countryside of millions of households; but with the use of tractors, power, economy and Usability are gradually decreased, especially due to the wear of the machine itself, the compression ratio within the cylinder is gradually reduced, starting performance also will decline, making starting difficult. The main cause of this difficulty in starting is the cylinder piston