Carbon deposit on the top of piston will form many hot surfaces, which will cause premature combustion and deflagration and shorten the service life of engine.

　　气门及其座圈工作面上聚有积碳，会引起气门关闭不严而漏气，出现发动机难启动、工作无力以及气门易烧蚀等不良现象。气缸盖部位有了积碳，会降低发动机的冷却效果，使发动机的动力性和经济性都大大降低。

　　Carbon accumulation on the working face of the valve and its seat ring will cause the valve to close loosely and leak, resulting in engine difficult to start, inadequate work and valve easy to ablate and other undesirable phenomena. Carbon deposit in the cylinder head will reduce the cooling effect of the engine and greatly reduce the power and economy of the engine.

　　气门导管和气门杆部积碳结胶，将加速气门杆与气门导管的磨损，甚会引起气门杆在气门导管内运动发涩而卡死。

　　Carbon deposit and cementing on the valve duct and stem will accelerate the wear of the valve rod and valve duct, and even cause the valve rod to move astringently and stuck in the valve duct.

　　活塞环槽内积碳，会使活塞环边隙、背隙变小，甚无间隙大墙坏造成活塞环胶结失去弹性，甚折断活塞环而拉缸。

　　Carbon deposit in piston ring groove will make piston ring edge clearance and back clearance smaller, and even cause the failure of large wall without clearance to lose elasticity of piston ring cementation, and even break the piston ring and pull the cylinder.

　　喷油嘴聚有积碳，极易卡死喷油嘴，造成发动机缺缸运行或突然熄火。

　　The fuel nozzle accumulates carbon, which can easily jam the fuel nozzle, resulting in engine cylinder shortage or sudden extinction.

　　预燃室启动喷孔聚有积碳，将堵塞喷孔，使发动机启动困难。

　　Carbon accumulation in the nozzle of the precombustion chamber will block the nozzle and make it difficult for the engine to start.

　　火花寒积碳过多，在燃油湿润后，相当于火花塞电极间并联分路电阻，造成火花寒漏电不能工作。

　　Spark cold deposits too much carbon, which is equivalent to parallel shunt resistance between spark plug electrodes after the fuel is wet, resulting in spark cold leakage can not work.