Adding an outboard motor to a boat with an inboard?

Discussion in 'Powerboats' started by Carvedoakfarm, Mar 30, 2013.

  1. Carvedoakfarm
    Joined: Mar 2013
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    Location: Ohio

    Carvedoakfarm New Member

    Hi everyone.

    We have a 19' Bayliner Capri boat with an inboard motor. We recently purchased a seasonal campsite at a lake with horsepower restrictions. So, we are hoping to be able to mount an outboard motor to the boat. The inboard is mounted to wooden block in the transom. The rest of the stern is fiberglass. Is it possible to mount directly to the fiberglass or do I need to add some wooden blocks for strength? The outboard is a 25hp. The fiberglass is in good shape.

    Help? Thanks!!
     
  2. rasorinc
    Joined: Nov 2007
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    Location: OREGON

    rasorinc Senior Member

    I'm assuming this is a second engine and the inboard will remain in the boat. In almost all cases adding an outboard requires beefing up the transom with plywood and a knee brace. Pictures of the transom will be a great help. A kicker engine can be mounted to the transon easily by using a bracket and you can goggle outboard motor brackets to see many of them. 25 hp is not so powerful that extensive bracing is needed. A single layer of 3/4" marine ply on the inside epoxied and tabed into the sides of the existing hull with some layers of fiberglass should do the job, a knee brace will also add a lot of strength. Without pics and knowing the thickness of the existing transom all this is basically a guess on my part.
     
  3. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I'm familiar with the Bayliner Capri 19, I've worked on quite a few.

    [​IMG]

    This is the transom of a Capri, obviously without the drive.

    [​IMG]

    This is the typical engine cover (there are several styles) and straddling seats.

    The deck cap shape makes access to an outboard difficult at best, but a heavy duty adjustable outboard bracket is possible. As Stan has mentioned, you will need to reinforce the inside of the transom skin with some plywood. 3/4" will do, but make it as big as you can fit, inside the port or starboard aft seat area.

    This assumes you don't have the lounge deck option, which makes access even more difficult. I'd recommend the outboard bracket on the starboard side, as there's less stuff in the way, compared to the port side, where the drive trim pump and hoses live. You'll lose the boarding ladder, though it could be swapped to the port side, with some minor modifications.

    There's two basic outboard brackets - a small one, designed for up to 15 HP kickers and often seen on sailboats and a second, heavier duty bracket, which can handle intermittent 25 HP use. Of course a 25 HP outboard isn't going to push this boat very fast, maybe 8 MPH will be about it and she'll be working pretty hard at this speed. 6 MPH will be about right for reasonable economy and engine wear.

    Once you remove the starboard seat and gain access to the transom, grind it clean with a 40 grit DA or whatever you have, insuring you have good "tooth" and the surface is well roughed up. Cut a piece of exterior grade (not exposure 1, but true exterior) to fit as large a area as the space will permit. Bond this to the inside of the transom with thickened epoxy (no Liquid Nails doesn't cut it). Once everything is dry, seal the plywood with straight epoxy and put the seat back together. Drill from the outside, for the bracket bolts and arrange for controls (steering, throttle, shift, etc.). If you're a novice at this sort of thing, you could get in over your head with all the hookups. Seek help from a local repair shop, for brackets, moving stuff and the like.
     
  4. Carvedoakfarm
    Joined: Mar 2013
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    Location: Ohio

    Carvedoakfarm New Member

    Thanks for the replies!

    Here are a few pictures: (Please note, our boat is what is called a "handy man special")

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    Ideally, we'd mount the motor on the left side. These pictures are all of the left side.

    Thanks guys!!
     
  5. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    That's one pitiful looking Capri. If that's the drive I think it is, you might as well just toss it in the trash now.

    The port side looks clear, though you'll still need to beef up the skin with some plywood.
     

  6. tunnels

    tunnels Previous Member

    This could be a perfect job fo a fibreglass bracket ! yes i know its just a 25 hp but is just a matter of filling the hole where the sterndrive came out of and stripping all and unwanted or not needed things out from inside the hull thats doing nothing . :idea:
    Could cheat a little with the 25 and take it to a out board tuning specialist and could get 30 plus hp or even more from the same motor !!!
    So with all the surplus weight gone it could be a surprise and get up and plane with one person on board . Arnt the 35 hp and 25 hp cowlings the same just swap and then tune the 35 !!:p
    With 2 strokes you can get almost 50 % + hp just doing some tuning !!:eek:
     
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