mounting outboard to inboard/outboard

[pcromien]

I would like to mount a 90-125 horse 4 stroke to a hull that currently has a 4 cylinder volvo i/o, the boat is a 21 foot double eagle. where would I find the brackets to hold the weight of the new outboard, or do I just weld up my own and mount:?: ? any idea of the cost or any special problems I may encounter?

[tlmopsman]

DandDMarine have a good website. I'm also in the process of figuring out how to do this with a 20' hydroswift cuddy.

[pcromien]

DandDMarine have a good website. I'm also in the process of figuring out how to do this with a 20' hydroswift cuddy.


any luck finding material on what is involved in converting to outboard with a bracket?

Paul

[dereksireci]

Try:

http://www.armstrongnautical.com/Repower.htm

http://www.gilmarine.com/new/gildrive.html

http://www.bbrackets.com/bracket.htm

djs

[pcromien]

thanks a bunch, I will investigate the links you suggested. It definately gives me more to go on.
Paul

[LEASEGUY]

google outboard brackets, gill makes many bolt on brackets that include flotation . your transom is probably very strong if it currenty has an i/o but check the intergrity of the wood when you remove the intermediate housing.

[funkyblues76]

What's the best way to remove/fill hole in transform from previous ib/ob?
Thanks!

[LEASEGUY]

When you remove your I/O make sure your transom isnt rotted, i made a template to form a wooden plug several layers thick to match transom thickness. I glassed the plug to seal it and glassed it a second time as i postioned the plug in the transom. When it setup i glassed it inside and out to a smooth finish,then used boat life as a bonding agent and i sandwiched the whole deal with 1/4 aluminum plate in and out, bolted the plates together with stainless bolts right through the transom. still solid after 17 years .
My plates were about 2 feet high by 18 inches wide( from rub rail to just above the plug) very solid. You might do with less but all your horse power is pushing rigt on that spot. The switch to ob from I/O dropped 300lbs off the back of the boat and moving the prop back a bit which decreased draft by 9 inches. Really worth doing.

[funkyblues76]

Thanks! Do you have any pictures? How did you attach new motor?
Thanks Again!

[LEASEGUY]

Sorry no pics in progress. the bracket that the motor goes on has 6 bolt holes.
The technical aspect is height and ride position,you likely have less wieght back there now and your draft will be shallower, make adjustments before you start drilling holes.

[charmc]

Here are some articles on setback brackets and their mounting:

http://continuouswave.com/whaler/reference/engineBrackets.html

http://continuouswave.com/whaler/reference/standardTransomBracket.html

and a good one on plugging the I/O transom opening:

http://www.capndsboatshed.com/filliohole.htm

Good luck!

[Jim Williams]

LEASEGUY...take a look at the pictures in my thread:
Transom Reinforcement for Outboard Conversion (http://www.boatdesign.net/forums/showthread.php?t=15706)
I'm just completing the plug step and will bolt on the bracket soon.
Jim

[charmc]

Jim,

While the "Cap'n D" article I cited uses wood plugs, resin and FG only, it looks like you are using a similar method with the addition of metal fish plates inside and out. This will add considerably to the strength of the repair, and I think it's a good idea. Being conservative about reinforcing a transom can only be good. Some transoms are built with a wood core, and moisture leaks from the I/O through hull opening can weaken the core in ways that can't be seen. Add that to the fact that the boat was designed and constructed with the weight of the I/O drive train all on the stringers, and now it will all be on the transom. It would seem that extra reinforcement is a good investment. Aluminum plate should be OK, but you'll need to make it thick enough to give the same strength as stainless. It should still cost less, and it's a lot easier to work with. Leaseguy's results, 17 years of service, "reinforce" (sorry 'bout that) the point.

[Jim Williams]

Sorry LEASEGUY, I was intending to point funkyblues76 to my thread.

[funkyblues76]

Jim, thanks for the info. Let me know how the bracket/engine instalation goes.

Thanks

[funkyblues76]

Jim, did you look into using a jack plate of any kind? thoughts?
Thanks!

[funkyblues76]

My transom is not flat across the back of my boat. Its like a large section of the transom molds out - like an indentation from inside the boat so it stands out from the back. It is orginal and stock, any new worries with a non-flat transom?

[charmc]

Funky,

From the picture of your boat you posted on your other conversion thread (maybe post it or one with the cover off for more detail on this thread), it simply looks like there is a molded setback in your transom. I don't see this as making any difference in the overall evaluation, except that your transom design may be a bit stronger than a simple flat one. All the plug and plate solutions suggested should still work.

Major thing to check, as Jim mentioned, is to be sure there is no rot inside the transom now. If there is, you'll have to cut away more until you get to sound material.

[Jim Williams]

Funkyblues,
I researched jack plates but they maxout at about 6" setback and I wanted to be able to raise my engine to the full trailer-tilt position which required a minimum of 24" setback. The only "jack plate" like bracket that might have worked ("Porta Bracket") was twice the price of my "Stainless Marine" bracket.

Jim

[funkyblues76]

Looking for an outboard for my 19ft. What kind of power do I need for fishing and pulling the kids around? Thinking 60-90HP? Can all outboards have steering cables attached to them? Thanks!

[funkyblues76]

What kind of measurments for outboard bracket do I need?
I've seen 24"-30". I need to support a 60-90HP motor. Thanks for the help.

[Jim Williams]

Funkyblues,
It's dependent on the brand of outboard and its' height. I called several bracket manufacturers and told them what motor I had and they recommended a compatible setback. They seem to know the dimensions of most outboards. The main reason for greater setback length is so you can tilt up for trailering/launching. If you have a splashwell built into your transom, or your transom height is low you would require less setback. From what I have read and been told by bracket makers you should get the shortest setback that meets your tilt requirement, if setback is too long you may have porpoising.

[funkyblues76]

porpoising? my transom is as high as the boat. Thanks for the help.

[funkyblues76]

Leaseguy & Jim W. how are the installs going? I'd like to see more pics on plugging the transom. Thanks!

[Jim Williams]

Transom plug finished...see my thread:
http://www.boatdesign.net/forums/showthread.php?t=15706

[Ecatasea]

try this beauty, just smaller???

http://www.kupoprodaja.com/roman-abramovich-yachts