Hey guy's. I have a 1987 tracker tx17 with a 1987 mariner 50hp. It had a 10 1/2 12P on it and i was getting 31 mph on gps and 6200 rpm's on new tach. Now the motor is 5800 rpm max so i went to a 10 1/2 13p which took me to 5800 rpm's and 34.9 mph on gps. I was totally happy nice speed and came on plane nice still. The down side was I got 10 miles less on 6 gallons of fuel. So back to the drawing board on a prop with better fuel. A local marine store told me to go back to a 12p because the one i replaced was an original 1987 with the motor and it may be out of pitch from it's age maybe a 10 or 11 pitch. So I went to a hustler 10 3/4 12P. now i'm running at 33.9 on gps and 6000 rpm's and have good fuel mileage back. Now the question is will i hurt this motor if I'm running only 200 rpm's over max because I think the setup is great now but don't want to blow the motor eather.