I have brought that up several times and everyone said I was nuts. you dont need the big seado jet boat motors.. look for something old and plentiful.. the yamaha 701's are all over the place...tons and tons of parts for them...made 75~85 hp stock. a prop is much more efficient than a jet too. as for counter rotating...wouldnt take much to make a 2 stroke run in he oposite direction.