FS490 Trimmer Air Filter The Part That Breathes For You

The air filter is the only part that breathes for the machine. The FS490 air filter is a flat paper element: pleated yellowish white media wrapped by an orange rubber sealing frame. All the air the engine takes in passes through that paper, and the dust, grass shreds and soil stop there. Clog it and the engine feels dull; tear it and dirt grinds the cylinder.

When is it time to replace it? Look at the paper. When the yellowish white media has gone dark with dust, when the pleats flatten and no longer spring back, when the edges are torn, or when the orange frame is cracked or warped, fit a new one. The media is a consumable, so do not soak it in fuel or wash it in water. Wipe it with a dry cloth, or blow it off gently with compressed air.

Two things when replacing. First the frame: the orange frame must sit tight on the housing, and a warped frame leaks dust even with fresh paper, so seat the four corners evenly instead of forcing it. Second the machine: the FS490 uses this filter, and similar cutters such as the FS450, FS510, FS560 and FS460 use similar ones, but they are not all interchangeable. Compare the old part's shape, or send a photo, before ordering.

Brush cutting is the harshest job for a filter. If the machine trims thick ground or works dusty, look at the paper more often. A filter takes minutes to change; a cylinder takes a season.