Hope you can help.<br /><br />I have a 1996 Mariner 60hp Bigfoot (2 stroke), with a 13 1/4, 17 pitch prop on it, it has a gear ration of 2.33, so I figure at 5500rpm i should be going about 36mph,(its fitted to a planing hull) when on the water i get to about 37mph and the motor does not sound...