Despite seemingly using it for everything, I only put around 50 hrs per year on my X500 garden tractor. As such I install a maintenance kit (air filter, plugs, fuel filter) every 100 hrs or every two years. However, I change the engine oil and filter every 25 hrs which is twice a year.
I noticed that it doesn't take very long for the outer foam air filter element to get pretty dirty whereas the inner paper element stays very clean.
So what I've been doing is I saved the foam outer element from my first air filter change and I washed it and let it air dry. Then, every 25 hrs when I change engine oil and filter I swap out the foam filter for a clean one, rinse and repeat.
It seemed silly to throw them away as they are virtually like brand new once you rinse them out and it gives me a nice clean air filter every 25 hrs without purchasing an expensive paper filter. Does anyone else do this?