Let your ZTrak™ engine breathe easy. Any engine with a clean air filter runs cooler and will last longer. Here are a couple of things to know about air filter maintenance on a ZTrak™ Riding Lawn Mower.. 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 100 hours. Changing an air filter seems like too much work? Change the air filter on your Residential ZTrak™ Riding Mower the easy way. Let’s go step-by-step on how to take off, discard and replace the air filter now. For specific information and more details check your Operator’s Manual.