799579 Lawn Mower Air Filter Compatible with B&S 4248, 5434, 799579 Air Cleaner Foam Filter Fits 09P602 09P702 550e-550ex Series 09P000, 08P000 Engine (4Pcs Filter+1Pcs Spark Plug)

What It Is

This is a 4-pack of foam air filters (plus one spark plug) designed to replace Briggs & Stratton part 799579. It fits select B&S engines in the 550e, 550ex, 09P000, and 08P000 series, commonly used on walk-behind mowers, pressure washers, and small tractors.

Fitment & Compatibility

Before buying, confirm your engine model number (stamped on the valve cover or blower housing). This filter fits B&S engines 09P602, 09P702, and all 09P000/08P000 series. It also replaces OEM numbers 4248, 5434, and 799579. For the spark plug, check your engine’s gap spec (typically 0.030” for B&S). This is not a universal filter—measure your current filter’s outer diameter (approx. 2.5”) and thickness (approx. 0.75”) to verify. If your engine uses a paper filter or a different mounting style, this won’t work.

Key Things to Know

• Quality: Foam construction—works fine for most homeowners, but may not filter as well as OEM paper in dusty conditions.
• Installation: Easy: remove old filter, clean the housing, slide in new foam, replace cover. No tools needed.
• Spark plug: Included plug is a basic copper type—fine for seasonal use, but replace it annually. Gap it before installing.
• Quantity: 4 filters give you spare replacements—swap every 25 hours of use or when visibly dirty.

Should You Buy It

If you own a B&S 550e/550ex mower with a foam air filter and want a cheap, no-fuss way to stock up on replacements, this is a solid deal. The spark plug is a bonus for a quick tune-up. Not ideal for heavy-duty commercial use or engines that require a paper element.