Air filter is the abbreviation of air filter element

During the operation of the engine, a large amount of air is drawn in. If the air is not filtered, the suspended dust in the air will be sucked into the cylinder, which will accelerate the wear of the piston group and the cylinder. Larger particles entering the space between the piston and the cylinder can cause severe "cylinder pulling", which is particularly serious in dry and sandy working environments. The air filter is installed in front of the carburetor or intake pipe, serving to filter out dust and sand particles in the air and ensure that a sufficient amount of clean air enters the cylinder
According to the filtration principle, air filters can be classified into several types, including filtering type, centrifugal type, oil bath type and composite type
When installing, whether the air filter is connected to the engine intake pipe by flange, rubber hose or direct connection, it must be tight and reliable to prevent air leakage. Rubber gaskets must be installed on both ends of the filter element. The wing nut that fixes the outer cover of the air filter should not be tightened too much to avoid damaging the paper filter element.

When maintaining, the paper filter element must never be cleaned in oil; otherwise, it will fail and may also cause runaway accidents. When maintaining, only the vibration method, soft brush removal method (brush along its folds) or compressed air reverse blowing method can be used to remove the dust and dirt adhering to the surface of the paper filter element. For the coarse filter section, the dust in the dust collection area, blades and cyclone tubes, etc. should be removed in a timely manner. Even if the paper filter element is carefully maintained each time, it cannot fully restore its original performance. Its intake resistance will increase. Therefore, generally, when the paper filter element needs to be maintained for the fourth time, a new filter element should be replaced. If the paper filter element shows problems such as cracking, perforation or delamination between the filter paper and the end cover, it should be replaced immediately.
When in use, it is essential to strictly prevent the paper core air filter from getting wet by rain, as once the paper core absorbs a large amount of water, it will significantly increase the intake resistance and shorten the service life. In addition, paper core air filters must not come into contact with oil or fire.

Some vehicle engines are equipped with cyclone air filters. The plastic cover at the end of the paper filter element is a deflector. The blades on the cover make the air rotate. Under the action of centrifugal force, 80% of the dust is separated and collected in the dust collection pocket. The dust reaching the paper filter element is 20% of the inhaled dust volume, and the overall filtration efficiency is about 99.7%. Therefore, when maintaining a cyclone air filter, be careful not to omit the plastic deflector on the filter element.