I need a prop for my merc. I just dont know what pitch will do what for the motor I have a 9x9 on it now and it does not perform very well, wont plane, no top end speed. I know its only a 9.9 but Im only getting about 8mph out of it. Should I be getting more? its a 2001 Merc. 9.9 4-stroke.Im not very educated on these things so please be patient...Thanks Im not even sure if this is the right size prop for my motor, anybody know what the factory prop should be?