Try just getting some of the foam filter spray and not putting any filter oil on the filter itself, i have had alot better luck that way and my carb or engine never has dirt in them anymore. I was still getting a little dirt in the engine while using filter oil on the filter itself but not on the foam prefilter. You can put the oil on the foam prefilter, and get an outerwears cover for it, keeps them clean and working properly with no issues, and you can be sure your keeping dirt out of your engines. I learned the hard way what a little dirt getting past the filter can do to your valves and piston rings, a little dirt can do alot of damage lol