Just like cars, lawn mower engines need their spark plugs changed on a regular basis. How often should you swap the old ones out for new ones?

As part of your routine lawn mower maintenance, you should replace the spark plug. But how do you pick the right one? The answer lies with the manufacturer.

A lawn mower that idles or runs rough could be an indication of worn spark plugs. Install a new, properly gapped plug after 100 hours of operation or once a season—whichever comes first.

From changing its oil to sharpening its blades, here’s how to prep your mower for summer.