When the pipes or cleaning cores of the air filter are blocked by dirt, due to the serious shortage of air intake, the engine has the following faults: After the pipe or filter element of the air filter is blocked by dust, the engine will have the following faults due to the serious shortage of air intake: When the accelerator pedal is continuously stepped on, the sound of the engine is dull, the acceleration response is slow, the operation is weak, the water plants are raised, and the exhaust gas is gray-black. If the above phenomenon occurs in the engine, it can basically be concluded that the air filter has been dry and blocked.

The second is the intuitive inspection method, that is, when the paper filter element is found to be gray-black, it means that it has been blocked and can no longer be used. Replace the filter if:
(1) When it is determined that the air filter element is blocked, it is necessary to maintain or replace the cleaning element in time. The criteria for deciding maintenance or replacement are:
After cleaning the dust on the surface of the air filter, when the dust is blown from the inside to the outside with compressed air, if the inner and outer surfaces of the filter element show the primary color, it indicates that the filter element can continue to be used; If the inner and outer surfaces of the filter element are gray-black, the filter element should be replaced with a new one.
(2) The inner surface of the air filter element is gray-black, indicating that the dust particles have penetrated the filter paper, and the filter element should be replaced immediately.
(3) The filter element that has been aged and deteriorated or has been washed with water and oil and has poor sealing performance should be replaced in time.