I have an E-Rude, 1979, 70 HP. On 15' Blue Fin. I <br />broke a prop last week (rough driveway). It is an OMC 13" x 19" (#382465). I replaced it with a Mich. Wheel "Vortex" 13" x 19". When I went out today with the new prop, I lost my hole shot, lost about 6 mph on top end and could tell the...