volvo md7a replacement with yanmar 1GM10

Discussion in 'Inboards' started by marto, Jan 9, 2007.

  1. marto
    Joined: Jan 2007
    Posts: 11
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    Location: philadelphia

    marto Junior Member

    I'm planing to replace the engine on a santana 30 sailboat
    it was fited before with a 13 hp two cilinder volvo md7a and 2:1 transmision and folding prop.
    Is it a good Idea to replace with a yanmar 9hp one cilinder that runs at the same rpm @ 3600 . normaly from factory they leave the engines runing very lite so I suppose the md7a was not at his limit using that prop.
    I was using a force 15 outboard before that push the boat at 6 1/2 nots at 3/4 trotle.
    I'm also planing to use the same volvo transmission and build a connection plate to stik them together.
    I'm new in the forum, thanks very much.
    Martin
     
  2. marto
    Joined: Jan 2007
    Posts: 11
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    Location: philadelphia

    marto Junior Member

    see if some one get intrested

    well another quest waht over power a boat needs to be safe in rough weather, lets have a boat with hull speed of 7'2 knots and I requierd 11 hp for hull speed in normal weather conditions , waht hp to prop would be safe , por example to breake into waves.
     
  3. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    Assuming the propeller was properly sized, it will be too big for the Yanmar. The hull speed of the boat is about 6.6Kt, so the outboard is sized just right. A 9HP in windy conditions may let you do 4Kt or so.
     

  4. marto
    Joined: Jan 2007
    Posts: 11
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: philadelphia

    marto Junior Member

    whell looks taht I will have sail more, spent more in sails, and go
     
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