490发动机的活塞连杆机构有两个特点:活塞顶部有球形燃烧室;连杆螺栓螺母为自锁螺母。根据这两个特点,可以用下面方法拆卸活塞连杆总成:先拆掉缸盖总成和油底壳盖板,用“17”的套管卸掉所有的连杆螺母,拿掉连杆盖和下瓦片。再用“200×24”的小活动板手,将其缩口插入活塞的球形燃烧室内,把活动板手张口即可提出活塞连杆总成。 490 engine piston rod mechanism has two characteristics: a spherical combustion chamber at the top of the piston; connecting rod nut nut for self-locking nut. According to these two features, you can use the following method to disassemble the piston rod assembly: First remove the cylinder head assembly and the oil pan cover, with “17 ” casing removed all connecting rod nut, remove Connecting rod cover and lower tile. Re-use “200 × 24” small activities wrench, its necks into the piston spherical combustion chamber, the activities of the wrench can be opened mouth piston rod assembly.