一台刚刚修完的东方红—28拖拉机,起动时用汽油着火,换柴油不着火。经检查发现,东方红—28拖拉机安装的是东方红—75拖拉机的活塞。原来,在检修时,机手误认为,这两种机型的活塞可以通用。其实不然,东方红—28拖拉机装用的是2125型发动机,东方红—75拖拉机装用的是4125A型发动机,这两种发动机的活塞直径虽然相同,但活塞顶部的构造不同,4125A型发动机的燃烧室容积大于2125型 A just completed the East Hong-28 tractor, starting with gasoline on fire, for diesel is not on fire. The inspection found that the Dongfanghong -28 tractor is installed Dongfanghong -75 tractor piston. It turned out that in the overhaul, the hands mistakenly believe that these two models of the piston can be universal. In actual fact, Dongfanghong -28 tractor equipped with a 2125 engine, Dongfanghong -75 tractor equipped with a 4125A engine, the piston diameter of the two engines although the same, but the top of the piston structure is different, 4125A-type engine combustion chamber Volume greater than 2125 type