Need help!!!! I got a 2002 sunseeker superhawk 50 with triple Yanmar 420 with trimax surface drives. I am having trouble with propulsion. I can only get the boat to do 8.5 knots with All three motors in gear. It has the original props which are in perfect condition and transmissions are full oil oil. They are zf 110 gts. At about 2500 rpm i shift into second gear and the boat slows down to about seven knots. Any help will be greatly appreciated.