Briggs and Stratton 4 Pack of 491055T Spark Plug

What It Is

This is a 4-pack of OEM Briggs & Stratton 491055T spark plugs, designed for small engines in lawn mowers, tractors, and other outdoor power equipment. Each plug is pre-gapped and ready to install.

Fitment & Compatibility

• Check your engine model: Fits Briggs & Stratton engines with a 14mm thread diameter, 0.750” reach, and 0.030” gap. Common on Quantum, Intek, and Classic series engines.
• Cross-reference your part number: Equivalent to Champion RJ19LM, Autolite 5094, and NGK BPR6ES. Verify your engine’s spec sheet or old plug.
• OEM vs aftermarket: This is genuine Briggs & Stratton, not a generic replacement—ensures exact fit and heat range.
• Measurements: Thread size is 14mm, hex size is 5/8”, and the electrode gap is pre-set to 0.030”. Confirm your engine’s gap requirement (some older models may need 0.025” or 0.035”).

Key Things to Know

• Pre-gapped but verify: The plugs come gapped at 0.030”, but always check with a feeler gauge—shipping can shift it.
• Installation difficulty: Easy for DIYers. Remove the spark plug boot, use a 5/8” socket, and torque to 18-20 ft-lbs. Don’t overtighten.
• Common gotcha: These are not for all Briggs engines—avoid if your engine uses a 13/16” hex plug or a different gap. Check your old plug’s part number.
• Quality: OEM means longer life and better ignition in cold starts compared to no-name brands. The 4-pack saves money vs buying singles.

Should You Buy It

Yes, if you have a Briggs & Stratton engine that requires the 491055T plug and you want OEM reliability. The 4-pack is cost-effective for maintaining multiple mowers or keeping spares on hand. Skip it if your engine uses a different plug number—fitment is specific.