I replaced my airbox and installed a replacement filter that replaces the airbox and was wondering what the advantages and disadvantages were. Does this increase horsepower, will it dirty up my carb when I ride on dusty trails, etc...? Thanks

 

MikeyM,
It sounds like you have a Uni filter now and assuming you have it oiled with a good filter oil and clean it often, like every time you ride those dusty trails, the filter should do fine keeping the engine free of dirt.I don't know about giving you any horsepower advantage, but I think you would see an improvement in performance through better breathing of your engine.
Something else you need to consider is that better air flow requires increased fuel flow to prevent running in a lean condition which can cause severe damage to your engine if allowed to continue.Without knowing what you ride or what other modifications you've made, I couldn't make any suggestions about jetting your carb
Oh, one other thing, don't go near the water with that naked filter!