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  1. #1

    Default Help with prop selection, 1998 75 HP, pontoon boat

    I am in the process of rehabing on an old 1976 28ft Aloha pontoon boat. I recently found a good deal on a 1998 75 HP Force outboard. The engine came off of a 18ft pontoon that had been used on a river and the prop is in pretty bad shape. I have had the new boat/motor combination on the water once, and even with a beat up prop, the old Force would push the boat at 15MPH (checked with the GPS on my phone) with four adults and two grandkids on board.

    Now that I know there is a chance that this combination is worth spending some money on, I am interested in replacing the prop, and probably adding a tach. I have spent most of the afternoon looking for info on calculating prop diameter and pitch, but have come up empty.

    The old prop is marked "F10.63 X 12P" I have not found and indication what this is, but am assuming it is a 10 X 12 prop. From the center of the hub to the tip of the blade measures about 5 1/4 inches.

    I know I need to adjust the prop for the larger boat, but don't know what I should be looking for. I plan on taking the boat to a marina and letting a mechanic look at the linkage adjustment, etc. It does have new spark plugs. The motor had not been used for about the last three years, and seemed to start missing about at about 3/4 throttle. Any thoughts or suggestions welcome.


  2. #2
    Join Date
    Aug 2017
    South Africa

    Default Re: Help with prop selection, 1998 75 HP, pontoon boat

    Do you want to go faster, or have more power? more pitch will add more speed but slow hole shot .... less pitch will give you a better hole shot but a slow top end ....

  3. #3
    Join Date
    Dec 2015
    maplevalley WA

    Default Re: Help with prop selection, 1998 75 HP, pontoon boat

    Fast is not really an option you want to achieve proper WOT rpm. They make pontoon props usually fully cupped give you more control pushing around a barge.
    It takes a nickle to go first class!
    If it aint broke dont fix it!!

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