Let your engine breathe easy. An engine with a clean air filter runs cooler and will last longer. Here are a couple of things to know about air filter maintenance. Check your air filter before each use. Look for loose or damaged parts and change if necessary. No problems? It’s still a good idea to change your air filter about every 50 hours or once a season. That’s about once every other mowing season. Need help on how? Go step-by-step into changing your air filter on a D100 Series Lawn Tractor now. For specific information and more details check your Operator’s Manual.