inboard to outboard conversion

eugene1e

Cadet
Joined
Jun 12, 2006
Messages
28
I am fixing to convert a 20 ft 1978 Bayliner with an inboard to an outboard I have a 3 foot custum made setback plate that is made from double walled 3/8 aluminum my ? is what do I have to do to the transom so it will hold the setback plack and a 1978 175 mercury outbourd <br /><br /> Thanks Eugene
 

surlyjoe

Chief Petty Officer
Joined
Nov 21, 2005
Messages
486
Re: inboard to outboard conversion

you'll need to cut the old trnsom wood back from the hole a bit into a shape thats easily duplicated being carefull not to get into the outside skin of the hull,then taper the edge of the hull where the opening is so you can get a bond to it with the new glass , the make a patch to fit your recess inside and glue it in, then lay up your glass from the outside.<br /><br />the inside is where you'll need to beef it up, try and layup the patch the same as the inside of the rest of transom is, then comes the beef..<br /><br />I would prolly lay some carbon cloth acrross the back where the bolts go through and then maybe a layer of matt and screw another 1/2" of plywood on, then glass the whole thing over like the inside of a normal outboard transom.<br /><br />a little overkill wont hurt...
 

eugene1e

Cadet
Joined
Jun 12, 2006
Messages
28
Re: inboard to outboard conversion

Actully I was planing to cut all the wood out and replace it with new wood but dont you guys think that the 2.5 foot setback plate is a litte mush for the transom
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: inboard to outboard conversion

If you're replacing everything then it can be built to handle it, you just need to make it stronger.
 

JasonJ

Rear Admiral
Joined
Aug 20, 2001
Messages
4,163
Re: inboard to outboard conversion

Make the transom more thick, and glass some braces from the transom to the stringers. Two should do. The setback plate will be applying twisting forces to the transom, so keep that in mind during your rebuild. Definately remove all the transom wood and build a single transom instead of scarfing wood into the hole. Once you have the new wood in, you can fill the hole in the shell with layers of glass.
 

studlymandingo

Commander
Joined
Mar 22, 2006
Messages
2,716
Re: inboard to outboard conversion

The pics did not come up on the post. Try to get them posted and we can get a better idea of what you need to accomplish.
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: inboard to outboard conversion

Normally the cost of the conversion is higher than just getting the boat and motor combo you want. But if you already have the bracket, motor and boat it should be OK, not cheap though, you will still need to buy a bunch of stuff to rig it.
 

eugene1e

Cadet
Joined
Jun 12, 2006
Messages
28
Re: inboard to outboard conversion

Ive already done 1 conversion But I didnt use a setback plate I cut the transom down and regassed in a gunwell the ? I'm not of is if I set the motor back 2 and a half feet to I still mount the cavition plate even with the botm of the boat are do I raise the motor up more since its so far back
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: inboard to outboard conversion

There are others here that can give you better info on set up, but it will need to be higher, about 1" per foot of set back (I think). Most of the time the AV plate should be a little higher than the hull even without a bracket. <br />You might want to start another thread with that question.
 
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