This fall I ran over the leaves with my tt60 mulcher and chipped them up and then with my other tt60, I picked up the leaves with my accelerater bagger. The problem is this is very dusty and after only 1 week my Donaldson Cannister air filter plugged up and my mower would not run under load. I replaced the air filter and new plugs which were all carboned up. This did not solve the problem so today my mower is in the shop getting the carburator cleaned. I do a lot of mulching and I have some large sandy lots I mow. In the summer, these jobs can be very dusty and I am lucky to get 2 weeks on an air filter. At $16 a pop, this can get expensive. I long for the days when I used an oiled foam filter that I replaced daily on the non cannister type air filters. My question is this? Does anybody use a bag or pre-filter over their cannister air filter? If so, where did you get it? I hear that an outfit in Schoolcraft, MI is testing a prefilter that is made out of microfiber sock that will fit over any style of air filter. It is washable, and does not need to be oiled to capture dirt. Any suggestions would be greatly appreciated.