S198柴油机采用水冷蒸发方式,由于水汽蒸发,沸水外溢,加上机器出厂时上止点刻痕较浅,使用时间久后,刻线模糊不清,给重新调整供油提前角带来困难。此时可不拆卸缸盖,采取下述方法近似确定上止点的位置: 1.拆下纸插螺栓,以便转动飞轮; 2.卸下缸盖罩壳,转动飞轮使活塞处在压缩行程,把进排气门的 S198 diesel engine adopts water-cooled evaporation method. Due to evaporation of water vapor and overflow of boiling water, as well as upper notch marks of the machine when leaving the factory, the etching time is long and the engraved lines are indistinct, which makes it difficult to readjust the oil advance angle. In this case, do not dismantle the cylinder head, and adopt the following method to approximate the position of TDC: 1. Remove the paper inserting bolt to turn the flywheel. 2. Remove the cylinder cover and turn the flywheel to make the piston compress the stroke. Intake and exhaust valve