What is the right spark plug and gap for my small engine?

Checking and changing spark plugs is an essential step in routine small engine maintenance and when troubleshooting problems with your lawn mower, snow blower or other outdoor power equipment. Follow this 3-step guide for resources to walk you through the process or jump to the section.

Before doing any small engine repair or maintenance, be sure to check your manual for recommendations on specific parts numbers and safety precautions.

Where is the spark plug located on my small engine?

Follow this step-by-step image guide to locate spark plugs in different Briggs & Stratton engine types. A spark plug wrench can help avoid engine damage when removing these parts for cleaning or replacement.

Spark Plug Location for FlatHead Engines

Also known as L head or Side Valve Engines, these engines are commonly used for walk behind lawn mowers and pressure washers.

Spark Plug Location for OHV (Overhead) Engines

Spark Plug Type & Gap Chart for Briggs & Stratton Engines

Now that you’ve found the part you’d like to replace, you can use the chart below to identify the genuine Briggs & Stratton replacement spark plug and gap recommendation.

CAUTION! Be sure to use the right spark plug! Although several different spark plugs may screw into the engine, using the incorrect one will result in performance problems and possible internal engine damage.

Flathead Engine Spark Plugs & Gaps

Also known as L head or Side Valve Engines, these engines are commonly used for walk behind lawn mowers and pressure washers.

If you have a Quantum engine, be sure to check the Code Date before doing any engine maintenance.
>> Find your small engine model number, code date and more.