That Filter Foam is a scary thing! My air cleaner housing on the Polaris Power Pole snow-thrower is EMPTY. Hopefully, as a snow appliance, it was ALWAYS empty. So far I've only inspected the carb diaphragm, which is stiff but intact. It has run, but not very well. Since I attempted to use gear oil in the gearbox, and the engine sucked it all out and burned it, I suspect the shaft seals. At least everything is well lubricated ;-)