Outboard instilation question - mounting bolt pattern

Discussion in 'Outboards' started by NTGeorge, Feb 12, 2010.

  1. NTGeorge
    Joined: Jan 2010
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    Location: Darwin

    NTGeorge Junior Member

    I've heard that all modern outboards have the same mounting bolt pattern, is this true?

    I ask as I need to drill the holes to mount a customers new Suzuki to his new boat and the local dealer is all talk an no walk, he's promised me the template for two weeks now but fails to drop it off. I have a MY06 100 Yamaha in the workshop so if the mounting pattern is the same I'll just measure it up and make my own template.
    I really need to get these hole drilled and am fast running out of time and patience.

    Any help would be great

    Cheers
     
  2. NTGeorge
    Joined: Jan 2010
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    Location: Darwin

    NTGeorge Junior Member

    Found this for those that were interested.


    "It is believed that the hole arrangement currently in use by most engine manufacturers follows these dimensions:

    •The top pair of holes are spaced 12 and 7/8-inch on center; each hole is 6 and 7/16-inch from the engine bracket centerline.
    •The bottom pair of holes are spaced 9 and 7/8-inch on center; each hole is 4 and 15/16-inch from the engine bracket centerline.
    •The spacing between the top and bottom pair of holes is 8-inches on center.
    •The centerline of the top holes is 2-inches below the top of the engine bracket. The holes in the transom should be 1 and 7/8-inch below the top of the transom. In no case should they be closer than 1 and 3/4-inch to the top of the transom. Holes located 1-7/8-inch below the top of the transom will produce a slight gap between the transom and the engine mounting bracket. This gap can be filled with an appropriate spacer or shim to help bear the engine's weight onto the transom.
    •When locating holes on the transom, do not assume the top of the transom is a straight or true edge. Determine the transom vertical centerline by measuring equal distances from the hull's chines. Align the engine mounting holes to the true vertical centerline of the transom, not to the top edge of the transom.
    There is no point in drilling holes in the above pattern if they do not match those on your engine. Generally a hole template is supplied with a new engine. Absent that, a template could be made from the actual holes on the mounting bracket of an existing engine. Locate the holes as specified with respect to their position from the top of the transom."
     
  3. hmattos
    Joined: Jun 2004
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    Location: Devon UK

    hmattos Senior Member

    Hi,
    In our experience there are two pattern sets depending on the engine horsepower. We fit new Suzuki and Evinrude engines, and all engines in the 40 - 225 hp are the same pattern, but smaller engines have, quite logically a smaller pattern.
    Have a look at www.explorermarine.co.uk if you want to see the reange of boats which we build
    Regards
    Hugh Mattos
     
  4. NTGeorge
    Joined: Jan 2010
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    Location: Darwin

    NTGeorge Junior Member

    Thanks Hugh

    Some good extra information to know, I cant imagine fitting an engine bigger than 225hp as my workshop isn't big enough to build a boat that big. But........

    Cheers
     
  5. Typhoon
    Joined: Mar 2009
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    Location: Australia

    Typhoon Senior Member

    I must be missing something. Offer outboard up to transom of boat on an engine hoist, get it where you want it, mark holes. Drill holes. Done.


    Regards, Andrew.
     
  6. Obsession
    Joined: Jan 2010
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    Location: Chicago, IL, USA

    Obsession Junior Member

    He didn't have the outboard from supplier yet and maybe he wanted to have time to seal the holes through the transom or such and let that set so it didn't get on the bolts, or maybe oversize drill, seal, and drill the holes.
     

  7. NTGeorge
    Joined: Jan 2010
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    Location: Darwin

    NTGeorge Junior Member

    Yea, probably should have said. I was ready to paint the boat and wanted to weld tube into the top two holes, then paint, then deliver to get the engine mounted.
    All done now, I marked and drilled then the next day the dealer dropped off the template. Measurements in previous post were spot on, template lined up spotty dog.

    Cheers
     
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