Forums General Discussion MAX PROP Propeller Recommendation

This topic contains 5 replies, has 6 voices, and was last updated by  Dunphyje 1 month, 1 week ago.

  • Author
    Posts
  • #225090

    Ben Frothingham
    Participant

    Hi All, I am tired of dragging my running gear around while sailing and am considering the beautifully expensive max-prop (or other feathering/folding) and looking for options/size recommendation for 424 with 1.5 inch shaft with 75 hp Yanmar and original V-drive. I know I can go through a process with PYI to get a recommendation but hoping some of you might have experience with Max Prop.
    Many thanks. Ben
    Papaya – 1979 Sloop, Hull #81, Woods Hole, MA

  • #225091

    rdugger
    Participant

    Ben
    I replaced our fixed prop with a Seahawk Autostream from Jim Blanchard at H&H Prop in New England several years ago (800-325-0117). We have had no issues with it. Unlike MaxProp it can be rebuilt by owner should the internal parts need replacing.

    Rick
    Eclipse

  • #225092

    Ryan Doyle
    Participant

    Hi Ben,

    We have a 19” 3-blade max prop on a 1.5” shaft and a Westerbeke 58 with the v-drive. We cruise at 6.5kts at 1800rpm.

    I have not had to rebuild my max prop, but Rick raises a good point. Our max prop came with our boat (so not sure of its age) but we have been very happy with its performance for over 3 years and it is still in quite excellent shape. I have found max prop to be responsive to my questions via email. Attached is a photo of the prop before we splashed this year – the grey color is from an anti barnacle spray.

    Ryan

    Juniper
    1983 424 Ketch “C” Layout
    New York

    Attachments:
    1. BE332532-AAF8-4E51-962C-5F3BF164CFF8.jpeg

  • #225094

    RichCarter
    Participant

    Ben,
    I researched this a few years ago, my notes are here.
    http://www.richardcarter.net/repower/Propeller.html

    Discussions with the propeller manufacturer indicated that the shaft-speed of the 75hp Yanmar is too high to properly mate a 3-blade propeller. The issue is tip-speed. At high tip speeds, the propeller will cavitate. I’d recommend that you have a similar conversation with your propeller supplier before you drop several boat-units on the wrong prop.

    I ended up replacing the V-drive to gear down the shaft speed. This isn’t really a waste of money since these RV-20s are at the end of their lives anyway.

    Rich

  • #225095

    Warren Stringer
    Participant

    Ben,
    We replaced a fixed prop with a MaxProp on our previous cape Dory 36. You will find you lose about 5% efficiency in forward, due to the blades being flat rather than curved. On the other hand, efficiency in reverse will be much greated and there will probably be less prop walk, for the same reason.

    For what it’s worth, we replaced the fixed prop on our 424 with a Gori and love it, but it is expensive. Mostly we wanted a folding rather than feathering prop because of all the crab pot lines here in the Chesapeake.

    Warren Stringer
    s/v Adagio
    Deltaville, VA

  • #225189

    Dunphyje
    Participant

    Just a quick comment… you can easily grease your Maxi Prop..
    Remove a couple alan head set screws located on the prop hub.
    Screw in a grease fitting (zert) and add grease using a grease gun until you see grease coming out.
    Then remove the Zert and replacer the set screw..
    Easy to do..
    John
    MS/V Mela

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