check it over and try to get it to turn 5600 with just you, at 5200, its down on power from what you reported earlier. I'm still concerned about your prop, that boat should be running a lot faster than 40
mph @ 5600 rpm, it should be in the upper 40's lower 50's with one person aboard and light load. What kind of prop are you running and what pitch. Have your run the boat this loaded(6 people) before?