whats better k and n or genuine part air filter ?

[Motorbreath]

I think they run a bit rich too (too fuel for a given air) so the cotton filter and the open exhaust compensate. Also looking at the sizes of the Dynojet kit, I think it is leaner than the standard one (if I did not interpret it wrong), when it is richer in most of bikes. Can anybody verify this?

The last times that a mechanic or I looked at the spark plugs they looked fine but I bought my bike used with an insane can, so I do not know if the fueling was adjusted.

I ask again, anybody is cutting the intake silencer? :evil