Briggs and Stratton 796112 Pack of 12 Spark Plugs (RJ19LM)

What It Is

This is a pack of 12 RJ19LM spark plugs from Briggs & Stratton, designed for small engines in lawn mowers, tractors, generators, and pressure washers. It’s a common replacement plug for 4-cycle engines, typically used in seasonal maintenance or bulk fleet servicing.

Fitment & Compatibility

• Check your engine model: RJ19LM fits most Briggs & Stratton single-cylinder engines (e.g., 500e, 550e, 750e, Intek, and older Quantum series). Also compatible with many Tecumseh, Kohler, and Honda small engines.
• Measure the gap: Factory gap is 0.030 inches (0.76 mm). Always verify with a gap tool before installing—pre-gapped plugs can shift in shipping.
• Thread size: 14mm thread diameter, 19mm reach (3/4 inch), with a tapered seat. No washer needed.
• OEM vs aftermarket: These are genuine Briggs & Stratton OEM plugs, not generic. They match the exact spec of the plug originally in your engine.
• Avoid for newer engines: Not recommended for Briggs & Stratton engines with electronic fuel injection (EFI) or those requiring a resistor-type plug (check your manual for “R” in the plug number).

Key Things to Know

• Quality: OEM plugs last longer and run cleaner than many aftermarket equivalents. Electrode is copper-core for reliable spark in light-duty use.
• Installation difficulty: Easy—remove wire, unscrew old plug with a socket wrench, gap new plug, hand-tighten then 1/2 turn with a wrench. Don’t overtighten (18-22 ft-lbs max).
• Common gotchas: The pack of 12 is a bulk value, but plugs can arrive with gaps knocked out of spec. Always check each one. Also, this plug is non-resistor type—if your engine has electronic ignition or radio interference issues, you may need a resistor plug (e.g., RJ19LMX).
• Shelf life: Plugs are fine stored dry and cool for years, but if the pack is split, keep unused ones in a sealed bag to prevent corrosion.

Should You Buy It

If you maintain multiple small engines (mowers, trimmers, snow blowers) that use RJ19LM plugs, this pack is a solid value at ~$2.16 per plug. It’s also good for a single mower if you want a 12-year supply. For a one-time replacement on a single engine, a single plug (often under $4) may be simpler.