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

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

Finding the Spark Plug on Your Engine
Use the Spark Plug Gap Chart to Find the Right Replacement & Setting

Before doing any 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 engine?

Due to the variety of engine and equipment configurations, your best source for spark plug information is your engine or equipment Operator's Manual. However, the following general guidelines will get you pointed in the right direction.

This guide provides the common spark plug part numbers used in our L-Head and Overhead Valve engines. For information regarding the service/replacement of spark plugs, please visit our servicing the spark plug FAQ. Please be aware that the size/shape of the spark plug varies depending on engine design.

Spark Plug Location for FlatHead Engines

Spark Plug Location on Flathead Engines by Vanguard Engines

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

Spark Plug Location for OHV (Overhead) Engines

Spark Plug Location on OHV (Overhead) Engines by Vanguard Engines
Small Engine Spark Plug Gap Diagram by Vanguard 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.

 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.