I have a 2002 Yamaha F115TLRA 4 stroke, I ordered a Yamaha 13 1/4 X 17 prop and I can not get the castle nut down far enough to get the cotter pin in and I went a little over torque (60lbs). I need about two turns on the nut. My other props fit perfect, I don't get it. Any thoughts ??? and Yeah...