2 Pack 491588s Lawn Mower Air Filter with Spark Plug,Replacement for Briggs and Stratton 491588 399959, Toro 20332 Craftsman 33644 Push Lawn Mower

What It Is

This is a 2-pack replacement air filter and spark plug set for Briggs & Stratton engines commonly used in push mowers and small lawn tractors. It includes one air filter (part 491588S) and one spark plug (replacement for 399959), designed for routine engine maintenance.

Fitment & Compatibility

Before buying, verify your mower’s engine model and series. This set fits Briggs & Stratton engines with part numbers 491588 (air filter) and 399959 (spark plug). Common compatible mowers include Toro 20332, Craftsman 33644, and many push mowers with B&S engines. Check your owner’s manual or current filter/plug part numbers. The air filter is a foam or paper element (about 3.5 x 2.5 inches), and the spark plug is a standard 14mm thread, 0.030” gap. Not for zero-turn, large riding mowers, or engines requiring different plug gaps or filter sizes. Measure your old filter and compare thread length (3/4” typical) before ordering.

Key Things to Know

• Quality: Aftermarket but generally reliable; some users report foam filter fits tighter than OEM. Spark plug is pre-gapped at 0.030”, but double-check with a feeler gauge.
• Installation: Easy – remove old filter and plug, install new ones. No special tools beyond a socket wrench for the spark plug. Air filter may require a slight squeeze to seat.
• Common gotchas: Air filter cover may be hard to snap shut if filter is too thick. Spark plug may not fire if gap is off; re-gap to spec if needed. Not for engines with oil-foam filters or different plug heat ranges (e.g., Champion RJ19LM).
• Value: Two full sets for $8.99 is cheaper than buying OEM parts separately; good for seasonal replacement.

Should You Buy It

Buy this if you have a Briggs & Stratton push mower that uses filter 491588 and spark plug 399959, and you want a low-cost, convenient maintenance kit. It’s a solid budget option for DIY homeowners who change air filters and plugs annually. Skip it if you need OEM-exact fit or have a high-performance engine requiring specific plug heat ranges.