New boater looking for some help. Just bought a 1994 28' chris craft with a 7.4 and volvo penta duo prop. If anyone other than myself is in the boat, they need to sit in the bow cabin in order to get on plane. Once up, WOT is 3,900-4,000. Engine sounds good but won't go past 2,800rpm if not on plane. I have C4 props on it now. I have deduced it down to the props or my timing is not advancing with the throttle. Any input will help.