500i/661 Air Cleaner System

Introducing a new concept in air cleaner design. This innovative system includes an exterior cage, high-density foam, and a polyurethane bushing, which captures dirt and foreign particulates more efficiently than paper or gauze.  Whether you're a professional or a heavy-duty chainsaw user, this product provides the filtration quality you can rely on. FEATURES: Increased surface area, including breathability from the back side of the filter. Polyurethane bushing prevents particulates from entering through the stud. Crafted to fit perfectly under your chainsaw's factory hood, offering a simple modification for improved engine protection. Includes one external cage and bushing, plus two washable foam filters. Comes with an instructional card that includes how-to videos. FITS:  Stihl 500i Stihl 661 IMPORTANT NOTES: This filter requires oiling with a foam filter oil (Do NOT use spray oil). To complement this, we offer BelRay or UniFilter Oil and Cleaner separately, ensuring your air filter remains in optimal condition. Your kit includes detailed installation directions - please read these thoroughly for proper setup and maintenance. INSTALLATION TIP:  When using our bushing, make sure that the flat portion is toward the motor and that it's snapped all the way down on the stud. Initially, when you first put it on, it will be stiff, and you may need to use a screwdriver and push down your 1/4-turn lock for the first time. After running for a while, it will loosen up.  Ensure your chainsaw is always up for the task. Shop our large inventory of air filter stacks, foam filter oil, and foam filter cleaner.  Q. Is this air filter washable? A. Yes, this 500i/661 filter is washable. Before reapplying foam filter oil, you can clean it with UniFilter Foam Filter Cleaner, Simple Green, Purple Power, or Super Clean Degreaser. Frequent cleaning guarantees that the filter will continue to efficiently collect debris and particles, preserving the best possible chainsaw performance. Q. How often should I change the air filter on my Stihl chainsaw? A. Use and operating circumstances determine how often you should replace the air filter in your chainsaw. It is advised to inspect the inside of the filter to ensure no dirt is making its way through. Another good practice is to pinch the outside of the foam filter. If you can detect a dense buildup, it may be time to wash and re-oil the filter.   Stihl® is a registered trademark of Stihl® Incorporated and is used only to describe their products.