5pcs 491588S Lawn Mower Air Filter Replacement for B&S 491588 399959, Air Cleaner

What It Is

This is a pack of 5 aftermarket air filter replacements designed for small engines, primarily Briggs & Stratton mowers, tractors, and generators. It replaces OEM part numbers 491588S and 399959.

Fitment & Compatibility

Before buying, verify your engine model number (found on the valve cover or blower housing). This filter fits most B&S single-cylinder engines with a side-mounted air cleaner housing, including the 500e, 550e, 625e, 675e, and 700e series. It will not fit engines with a round, foam-only filter or those requiring a pre-filter. Check the filter dimensions: roughly 4.25” x 3.25” x 1.5” (L x W x H). If your current filter matches these measurements and has a black plastic frame with a paper pleated element, this is the correct fit. Cross-reference with OEM B&S 491588, 399959, 793602, or 793601.

Key Things to Know

• Quality is decent for the price – These are paper elements with a foam edge seal. They’ll filter fine for regular residential mowing, but dirtier or dusty conditions might call for a premium OEM or brand-name foam-prefilter type.
• Installation takes 2 minutes – No tools needed. Just unclip the air cleaner cover, swap the old filter, and re-secure the cover. Make sure the foam seal sits flush to prevent unfiltered air from entering.
• Common gotcha: check the seal – Some aftermarket filters have a slightly thinner foam edge than OEM. If air leaks around the seal, your engine can ingest dirt. Press the filter into the housing firmly before closing.
• Works on many small engines – Besides B&S, this filter is compatible with some Murray, Craftsman, Snapper, and Husqvarna mowers using the same housing. Always compare the old filter shape and size.

Should You Buy It

If you own one or more B&S engines that use the 491588-style filter and want a budget-friendly way to stock up for the season, this 5-pack is a solid value. It’s not for heavy-duty or commercial use, but for typical home lawn care, it’ll keep your engine breathing clean without overspending.