I have a Grady White 25 Ft. Sailfish 254 with Volvo Penta KAD42A deisel (fresh water cooled) with duo prop outdrive.<br />Engine overheats at 3600 rpm (max rpm is 3900). Overheats at lower RPM in strong headwind or rough sea. Temp. goes up to 205 and remaing there. If I reduce RPM temp goes...