There is gasoline in the air filter waste oil pipe.

It is caused by poor engine combustion.

If there is gasoline in the waste oil pipe of air filter, it is mainly caused by poor engine combustion, that is to say, poor engine combustion, and then there is more exhaust gas in this intake branch pipe including this air filter element, so this phenomenon will occur. It is necessary to clean the throttle and fuel nozzle, replace the spark plug, check the carbon deposit in the engine cylinder and check the engine exhaust valve to see if there is any problem. These aspects need specific inspection and treatment.