i see alot of guys who get dirt in their motors and it dont seem to matter what filter they use....its all in how you set em up....i sue mugan replacement filters i soak them with pj-1 foam air filter oil(motorcycle stuff)this oil is real sticky...i ring out the excess oil and i pack the ends of the filter housing with a small amount of grease to help trap any dirt...i also use the ofna outer sleeve filters for a added protection....i never ever and i mean never wash a filter and re use it....i wont risk a 400 dollar motor to save a 2 dollar filter just isnt worht it to me...ill use a filter a few times and throw it away