491588S 491588 Air Filter + 493537S 493537 Pre-cleaner for 675ex 725ex 625e 625-675 Series 3.5-6.5 HP Quantum Engines W Spark Plug

What It Is

This is a two-piece air filter kit (pre-cleaner + inner filter) plus a spark plug, designed for Briggs & Stratton Quantum engines in the 625e, 675ex, 725ex, and 625–675 Series, typically found on walk-behind mowers, pressure washers, and generators with 3.5–6.5 HP.

Fitment & Compatibility

Check your engine model number (stamped on the valve cover or near the oil fill). This kit fits Briggs & Stratton Quantum engines with model numbers starting in 10T502, 10T902, 10T702, 10T802, 10T102, 11T902, 11T802, 12T702, 12T802, 12T902. It replaces OEM part numbers 491588S (air filter) and 493537S (pre-cleaner). The spark plug is a standard J19LM or equivalent. Measure your current filter’s outer diameter (~3.5 in) and height (~1.5 in) to confirm—this is a round foam and paper combo, not a flat panel. Works on most walk-behind mowers with those engines, but not for Intek, Classic, or Vanguard engines.

Key Things to Know

• Quality vs OEM: Aftermarket foam and paper are slightly less dense than OEM, but still effective for residential use. The spark plug is a basic copper core—fine for seasonal mowing, but not long-life iridium.
• Installation: Easy—remove old filter, slide pre-cleaner over the inner filter, and snap into the air box. No tools needed for the filter; use a 5/8 in socket for the plug.
• Common Gotcha: The pre-cleaner is foam and must be oiled lightly (use foam filter oil or motor oil) before install—running it dry lets fine dust pass through. The paper inner filter stays dry.
• Frequency: Replace both filters every 25 hours or once per season. The spark plug every 100 hours or if starting issues arise.

Should You Buy It

Yes, if you have a Briggs Quantum engine and want a cheap, easy replacement for routine maintenance. It’s a solid value for the price, but if you mow in heavy dust or need maximum longevity, consider OEM filters and a platinum plug separately.