799579 Air Filter Tune Up Kit Fit for B&S 550E 500E 300E 450E 55EX 08P502 09P602 09P702 Fit for Craftsman CMXGMAM1125501 Fit for Troy Bilt TB110 TB115 TB554 Lawn Mower with Spark Plug Primer Bulb

What It Is

This is an air filter tune-up kit for small Briggs & Stratton engines (550E, 500E, 300E, 450E, 55EX series) and compatible Craftsman/Troy-Bilt push mowers. It includes a foam pre-filter, paper air filter, spark plug, and primer bulb—everything needed for a basic annual service.

Fitment & Compatibility

Before buying, check your engine model number (stamped on the valve cover or blower housing). This kit fits B&S engines 08P502, 09P602, 09P702, and the 550E/500E/300E/450E/55EX series. It also fits Craftsman CMXGMAM1125501 and Troy-Bilt TB110, TB115, TB554. Not for OHV, Intek, or larger B&S engines—those use different air filter housings. Measure your air filter base: the paper filter is roughly 4.5" x 3.5" x 1.5". If your mower has a different air filter shape (round or taller), this won’t work. The spark plug is a standard B&S RJ19LM or equivalent—verify your plug gap (0.030") before installing.

Key Things to Know

• Quality is budget-level, not OEM. The paper filter is thinner than genuine B&S; the foam pre-filter is adequate for light use but may degrade faster in dusty conditions.
• Installation is easy (10 minutes). Remove the air filter cover, swap the old paper and foam, replace the spark plug (gap it first), and push in the new primer bulb. No tools needed for the bulb.
• Common gotcha: The primer bulb may be slightly different from your original—it’s a universal fit, but check that the stem matches your carburetor’s primer hole. If it’s too loose or tight, reuse your old bulb.
• Spark plug included is basic copper core. Fine for a season, but if you want longer life, buy a separate iridium plug.

Should You Buy It

Buy this if you have a compatible B&S 550E/500E series engine and want a cheap, convenient one-stop kit for a basic tune-up. It’s fine for light residential mowing, but skip it if you need OEM-grade filtration or a perfect primer bulb fit—buy individual parts instead.