NEWBIE HERE AND NEED PROP HELP. I HAVE A 24' HARRIS PONTOON WITH A 70hp JOHNSON. THE OLD PROP IS TO CORRI-ED AND I CAN NOT READ THE MARKINGS ON IT. I THINK IT'S ABOUT 13.5" IN DIAMETER FROM LAYING IT DOWN AND TRYING TO MEASURE IT. I JUST NEED A PROP TO POCK AROUND AND ALSO TO GET TO PLAN AN JUST...