Power Equipment Spark Plugs

Did you know there are several different spark plugs for power equipment applications? With so many spark plug options, it is very important to use the correct spark plugs for each application. Grouping all power equipment spark plugs into “long” or “short” spark plugs is not specific enough to meet the necessary spark plug design demands for each different engine. When NGK spark plugs are used as original equipment, the NGK plug number is stamped into the metal around the base of the spark plug.

Critical design specifications include:
• Heat range
• Thread size/reach
• Projection
• Seat-style

Heat Range – critical to keep spark plugs from pre-ignition and fouling.

Thread Size/Reach – critical to spark plug functions including heat dissipation.

Projection – a plug with more projection than specified may cause piston interference.

Seat-Style – spark plugs are available in both “tapered” and “gasket”-seat styles, which must match the cylinder head specifications.

Use caution with cross references, as cross references should be used as reference only and may not provide a perfect apples-to-apples replacement. Whenever possible, note the specific engine model information, in order to look up the correct spark plug in a catalog. Spark plug manufacturers’ print and online catalogs should be checked whenever looking up spark plug part numbers.

Incorrect spark plugs can result in damaged equipment and increased down time. To a professional landscaper, down equipment means lost opportunity, i.e., productivity and profits. Taking the time to use the correct spark plugs can help prevent this aggravation.

Keep the machine’s owner’s manual handy. It is a good idea to keep a list of frequently replaced service parts for each piece of equipment owned, as a folder or notebook containing the equipment model information and part number information for items such as spark plugs, filters and blades—this will help ensure the correct parts are ordered. It is also a good idea to make a note of the date each machine has been serviced, to see to it that recommended maintenance intervals are met.