The new throttle will emit black smoke.

1. The combustible mixture is too strong. 2. There is too much oil in engine fuel. 3. The piston ring or crankshaft oil seal is poorly sealed. 4. There is moisture in the fuel. 5. The spark plug 6 is damaged. Dirty air filter

Second, troubleshooting.

1. The inspection and diagnosis of combustible mixture is too rich, so the carburetor and air filter should be mainly inspected.

2. There is no comparison between mixed oil and engine oil, or the brand of engine oil used is wrong. If the mixed oil contains too much engine oil or the engine oil quality is poor, the engine oil of combustible mixture can not be completely burned, resulting in black smoke. The above phenomenon will also occur in a two-stroke engine with separate lubrication, when the oil pump loses balance and supplies too much oil. At this time, the oil pump should be checked and adjusted according to regulations to ensure the proportional supply of lubricating oil under different throttle opening.

3. The four-stroke engine is excessively worn or damaged, and there is too much engine oil in the crankcase, which will cause the engine oil to string into the combustion chamber, resulting in too much engine oil in the mixed gas. If the crankshaft oil seal of a two-stroke engine breaks, the oil in the transmission string will also enter the crankcase and enter the combustion chamber with the mixed gas.

The reason why fuel and water are mixed together is because the fuel in the fuel tank itself contains water. At this time, the fuel tank should be cleaned and replaced. Another reason is that the cylinder gasket of the water-cooled engine is broken and cold water enters the cylinder. . If there is no leakage, the water in the water tank is consumed too fast, and the smoke emitted by the exhaust pipe is slightly white, which is probably the reason, and the cylinder gasket should be replaced.

It is rare for gasoline engines to emit black smoke. Black smoke is mainly caused by incomplete combustion of fuel in the combustion chamber. Under the condition of high temperature and lack of oxygen, diesel oil can't be fully burned, so it decomposes and aggregates to form soot, which is an aggregate with a small diameter.

Because the reaction speed of this aggregate is much slower than that of vaporized fuel, due to the high temperature and oxygen-deficient environment of the combustion chamber, it can not be fully burned again and then discharged through the exhaust pipe, so it presents black smoke.

The direct consequence of this phenomenon is that the diesel engine has high fuel consumption, low power and a large amount of carbon deposits in the piston and piston ring valves. In severe cases, the piston ring will be stuck and the valve seal will leak. At the same time, it will accelerate the wear of parts, thus reducing the service life of the engine. Therefore, we should pay special attention to this aspect.