4125型柴油机长期以来的难题就是修后功率难以恢复,比油耗大,同时还伴有窜机油现象,以致于有些机手认为东方红—75型拖拉机的经济性、动力性都不如东方红—54型拖拉机好。上述看法并非全错,这是因为东方红—75型拖拉机活塞顶部涡流室太大,实际压缩比低于理论值,活塞顶部直径太大,活塞上的活塞环槽偏深,致使活塞环的背隙太大,从而使活塞与气缸壁之间的密封性能变差和出现窜机油现象。1983年拖拉机冬季检修 4125-type diesel engine long-term problem is difficult to recover after repair power, fuel consumption than large, but also accompanied by the phenomenon of channeling oil, so that some hand that the DFH-75 tractor economy, power is not as good as Dongfanghong -54 Good tractor. This view is not the whole error, this is because the Dongfanghong -75 tractor piston vortex chamber is too large, the actual compression ratio is lower than the theoretical value, the piston top diameter is too large, the piston ring groove on the piston deep, causing the piston ring back Gap is too large, so that the sealing performance between the piston and the cylinder wall deterioration and the phenomenon of channeling oil. 1983 tractor winter maintenance