I would run it with you and 1 other person for a good 5-10 mins , taking out any excess weight off the boat (i.e. fat sacs, floats, boards, etc...), and then check the bildge area for how much water your taking in or any leaks you may have. It might just be the pump or something else.

I have an 86' sunsport and the eye hook for where I tighten the trailer strap is usually 6-10 inches out of the water.

I bet its helping you throw a better wake tho...