What Causes a Small Gasoline Engine to Emit Black Smoke?

[LeCameron]

Wear and tear on valves, piston rings, and cylinder liners can lead to insufficient compression pressure and oil entering the combustion chamber. This alters the normal fuel-air mixture ratio at the end of the compression stroke, causing the fuel to burn under oxygen-deficient conditions and resulting in the emission of large amounts of black smoke. Combustion Chamber Issues: Changes in the combustion chamber shape due to manufacturing quality or long-term use can degrade technical conditions, leading to excessive or insufficient compression clearance and incorrect piston positioning. These factors alter the combustion chamber's shape and volume, affecting the quality of fuel-air mixture and worsening combustion conditions. Fuel Injector Problems: If the fuel injector fails to atomize the fuel properly, atomizes it poorly, or drips fuel, the fuel cannot adequately mix with the air in the cylinder or burn completely, leading to the formation of large amounts of black smoke.