Let’s get started. No, really. Your Residential ZTrak™ Riding Lawn Mower will not start without proper spark plug care. Be sure to check your spark plugs at the end of each growing season to make sure the space and contact quality is still good and working properly. Just as importantly, John Deere recommends you change your spark plugs every 100 hours or once a mowing season. We’ll take you step-by-step into how to change the spark plugs on your Residential ZTrak™ Mower now. So, let’s get started. For specific information and more details check your Operator’s Manual.