20-07-2006, 08:20pm
I was told the cotton filters clog more slowly so the bike holds it mapped tune for longer.If you put a brand new filter and a k&n,bmc,dna etc in the bike i doubt you,d see 2hp.Mine was run with a dirty stock filter and no filter and there was about 3hp difference(to check the change in air fuel ratio).So either change the stock one regularly or use a cotton filter provided you don,t over oil it. Glenn the Spa Man<i></i>