(4) Improper adjustment of fuel supply time, there are two types:

a. The exhaust pipe emits black smoke, and there is a crisp knocking sound in the cylinder at the same time, and the work is rough. This phenomenon is generally caused by premature fuel supply time. Too early fuel supply time will usually cause difficulty in starting.

b. The exhaust pipe emits black smoke, and there is a flame in the muffler, making the sound dull. This phenomenon is caused by the late fuel supply time. If the fuel supply time is too late, it often causes the diesel engine to overheat, the exhaust temperature rises, and the parts may even be burned out. In addition, the diesel engine with automatic fuel supply angle advancer emits black smoke at high speed, which may also be caused by damage to the automatic fuel supply angle advancer. The automatic fuel supply angle advancer should be disassembled and inspected. If the oil supply time is improper, you can check and adjust according to the aforementioned methods.

(5) Uneven oil supply of each cylinder exhaust pipe emits black smoke, and the machine vibrates severely, supplying too much oil to individual cylinders, which can be checked and eliminated by the "cylinder breaking method";(6) Poor quality of dieselThe poor quality of diesel fuel causes poor atomization and can not completely burn. Clean the fuel tank and replace the diesel.