I have been working on this thing for awhile. i have done the carbs new plugs set the timing new water pump and i still have a hard time getting it to plane out. its on a 16' hydroswift fiberglass and has a prop 13x15. once it get it on a plane she cruzes along. But i can only max the tach at 2500rpm and the pitock speedo says about 25mph. any help would be great i'm stumped.