air filter

I have a 2001 warrior that is totally stock except for a full FMF exhaust (headpipe and muffler). I think the guy i bought it from had it jetted wrong. So what size jet and needle placement? It coughs through the airbox at idle and low speeds but runs great when you romp on it. It isnt the...

Hi I just got the K&N air filkter for my Raptor 350. the cover (air box lid) of the air filter box do not fit when the K&N filter is installed. It is necessary to put the lid back? What are the pros' & cons' of leave it with out the lid? Please help. thanks

looking to add a fmf powercore 4 exhaust and eventually something along the lines of a pro design air filter, but one wont break the bank. what size jets, carb kit or what ever do i need to add. my 2002 warrior already has pretty poor throttle response almost a dead spot. so looking for...