need transom dimensions

Discussion in 'Boat Design' started by navimatt, Aug 25, 2008.

  1. navimatt
    Joined: Aug 2008
    Posts: 1
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    Location: victoria bc

    navimatt New Member

    Hello all. i am in the process of fitting an outboard motor on a 17' skiboat that once had an inboard. i have taken the old motor out along with the leg and i am now ready to replace the transom with the new stronger one but im not sure how much space is needed for the outboard. for example the height from the bottom to the mounting edge and left-right for steering. also for the motor well how far into the boat should i allow for tilting the motor up and what not. this is all new to me so any advice and dimensions would be great.
     
  2. CTMD
    Joined: Dec 2007
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    Location: Melbourne, Aus

    CTMD Naval Architect

  3. BHOFM
    Joined: Jun 2008
    Posts: 457
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    Location: usa

    BHOFM Senior Member

    I would say, go look at some boats, without make and
    model or pictures, this is sort of a hard question!

    Take your tape measure and if you know the people
    a camera!
     

  4. Gilbert
    Joined: Aug 2004
    Posts: 525
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    Location: Cathlamet, WA

    Gilbert Senior Member

    Traditionally, the recommendation for transoms for outboards is to slope them aft about 12 or 13 degrees. For a standard length (15") shaft and a flat bottomed boat you can sometimes get away with having as much as a 17" high transom, but it may ventilate at times and if so you would probably want to reduce the height until it doesn't.
    With a vee bottom you will likely not get away with having it that high. But it is easier to cut the height down than increase it. Then there are jack plates and all, which I have no experience with, so someone else will have to discuss.
    Generally, I would not recommend an outboard well unless you really need it to protect the motor from getting bashed; there is a very significant efficiency loss. It also diminishes the interior room. If you do put in a well, the transom doesn't need to be beefed up. If you do offset the motor, don't offset it to the left, the steering will likely be worse. If it has much vee, I wouldn't offset it at all.
    That's about all I can offer.
     
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