I have a new Polarkraft aluminum modified V fishing boat and a Mercury 40hp four stroke EFI engine. This setup weighs about 1100 pounds at normal load.<br /><br />I currently have an aluminum 10-1/8x15 prop and the motor is rated at 5500 to 6000 WOT.<br /><br />I can get the motor to go to 5700 if I trim it out quite a bit but the boat porpoises alot. Trimmed in more the boat rides great but I only get 5300 rpm's out of it.<br /><br />Should I go down a pitch or two so as to increase the rpm's or leave this setup alone?