The petrol engine avoids the phenomenon of engine oil ejection, omits an original oil cavity baffle plate device, reduces a sealing gasket, and has simpler structure and more convenient installation. 本实用新型避免了喷机油的现象,并且取消了原有的油腔隔板装置,减少了一张密封垫,从而结构更加简单,安装更加方便。