Insufficient fuel supply. The return oil control valve in the pump cover oil passage is not tightly closed, causing the engine to operate unstably. In severe cases, the engine may stall with a slight increase in load, and starting may be difficult.
2. There is an oil leak in the oil circuit, the air or fuel filter is blocked, the incoming oil is not smooth, and the engine is unable to operate.
3. The sealing gasket of the oil outlet valve is broken and leaking oil.
4. There is carbon buildup inside the engine, which needs to be checked and cleaned.
5. The fuel supply advance angle is incorrect.
6. The air filter is blocked, and the amount of air sucked into the cylinder is insufficient, resulting in incomplete combustion, black smoke from the engine, and weakness.
7. The fuel supply of the fuel transfer pump is insufficient.
8. The exhaust pipeline is blocked, which affects the discharge of exhaust gas. At the end of exhaust, the pressure inside the cylinder is high, which affects the intake of fresh gas and leads to poor combustion after fuel injection.
