When you run WOT @ 6000rpm, what kind of weight--including fuel load is in the boat? Boat manufacturers will and do "prop" boats so that when loaded up with people, gear, and fuel so that it will run close to the recommended rpm at WOT. So, you might have the right prop for what the expected use of the boat was built for. But if you run with no fishing gear, an empty live well and 1/4 tank of fuel, and it's just you on board, I could understand that you're running too high of rpm. Try a different prop. You'll get a better hole shot, and you'll run rpm in the right range.