为了使读者对东方红-75拖拉机各种零件的安装方向有更系统、全面的了解,我对本刊1987年第2期刊出的“谈4125A发动机部分零件的安装方向”一文作如下补充: 1.起动机 (1)缸盖螺栓旋入缸体时,应使其螺纹较短的一端旋入机体(长为12毫米),以保证螺纹沉入机体平面及安装牢靠。 (2)旋入缸盖螺母时,应使螺母较光滑的一端 In order to make readers have a more systematic and comprehensive understanding of the installation direction of various parts of Dongfanghong-75 tractor, I would like to add the following article on the installation direction of part 4125A engine part published in the 2nd issue of 1987 : 1. Starter (1) When the cylinder head bolt is screwed into the cylinder body, the shorter one end of the screw thread should be screwed into the body (12mm long) to ensure the thread sinks into the plane of the body and the installation is firm. (2) When screwing the cylinder head nut, make the nut smoother end