Inboards don't have airfilters they have spark arrestors. Anything installed on the intake of an inboard must be marine for this property or else there is a large explosion hazard. Are you hearing a loud sucking noise? This is common with spark arrestors because of metal and the small gaps between them they whistle a bit, especially on take off. A new 496 sounds like a jet engine winding up when they take off because of the large air intake.