Briggs & Stratton 793541 Spark Plug

What It Is

The Briggs & Stratton 793541 is a standard-resistor spark plug designed for small engines, primarily in lawn mowers, tractors, and other outdoor power equipment. It’s a direct replacement for many Briggs & Stratton engines, delivering the spark needed for ignition in 4-stroke gas engines.

Fitment & Compatibility

Before buying, check your engine’s model number (not just the mower brand). The 793541 fits many Briggs & Stratton engines—common on models like the 12.5 HP, 17.5 HP, and 20 HP Intek and Endurance series. It’s also used in some older Toro, Murray, and Snapper mowers with Briggs engines. Verify the gap: this plug requires a 0.030-inch (0.76 mm) gap. Measure the old plug’s thread length and reach—this is a 14mm thread with a standard 3/4-inch reach. Avoid using it in engines that call for a longer or shorter plug (e.g., some Kohler or Honda engines). If your mower’s manual lists a different Briggs part number (like 691043 or 796560), cross-reference via Briggs’ online lookup tool.

Key Things to Know

• Quality: This is OEM Briggs & Stratton, not an aftermarket knockoff. It’s pre-gapped but always double-check with a feeler gauge—shipping can shift it.
• Installation: Easy DIY job—remove the old plug with a socket wrench, screw in by hand to avoid cross-threading, then torque to about 20 ft-lbs. No special tools needed.
• Common Gotchas: Don’t overtighten; aluminum cylinder heads strip easily. Also, if your engine is a single-cylinder, this plug works fine; for V-twins, verify the heat range matches your engine’s spec.
• Lifespan: Replace every 100 hours or annually, whichever comes first. If the engine runs rough or hard to start, this plug is a cheap first step.

Should You Buy It

If your mower uses a Briggs & Stratton engine and you need a reliable, drop-in replacement spark plug, the 793541 is a solid choice—especially at this price. It’s a straightforward swap for DIYers, and the OEM build ensures consistent performance. Skip it only if your manual specifies a different plug type or reach.