Air filters
 

Hi

I'm looking for some advice about air filters

How offen do you recommend replacing them with new ones? I'm changing mine after every race day and clean it and re-oiling it. How many time can I be used before I need to replace it?

I've got a 2 stage filter and there's some dirt stuck in the outer foam. There's not much but I can't get it out no matter how I clean it. The inner foam is like new, should I worry about it?

Also what filter elements do you recommend.

Thanks