I/O to OB conversion

thurps

Chief Petty Officer
Joined
Jan 14, 2007
Messages
538
How big of a boat have you converted from I/O to OB. I?m looking at a 24? Reinell.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,084
Re: I/O to OB conversion

Ayuh,........

I've seen Several done by several different people, several different ways,.......
The boats were in the 20' to 25' class,........

Btw,..........
None were Sucessful,+ all were Sold or Junked within the year.......
 

SuperNova

Lieutenant
Joined
Mar 16, 2007
Messages
1,455
Re: I/O to OB conversion

I did a 21' Century a few years ago. It originally had a MR drive with an inline six. We removed everything, sealed up the hole in the transom (the toughest part), closed up the floor and installed a jackplate/seadrive to the transom and mounted the new engine to that. It has worked fine for 18 years in the Chesapeake Bay waters. I don't know if the effort was worth it or not, but at the time we hadn't done one yet..so the experience was worth it. If you do it right and don't attempt any shortcuts with materials or time..it should work fine. Our fuel tank was moveable to a certain extent, so that helped re-balance the boat, and a set of trim tabs really helped overall.
--
Stan
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: I/O to OB conversion

I have seen a lot of negatives about I/O to outboard conversions.
I do have a friend with a 17 ft Starcraft from the 70s converted to outboard.
Presently a 1985 50 Merc.It is adaquate for fishing even though he is 330#
and usually fishes with 2 other guys.
As I understand it there is usually weight placement/hull configuration problems when moving the weight even farther rearwards.Perhaps my friend gets by because of his relatively light motor and somewhat low performance expectations.
 

seabasser

Cadet
Joined
Dec 1, 2007
Messages
26
Re: I/O to OB conversion

i have done a 25' conversion took out a 318 chrysler 225hp and put on a 150 merc, gained about 15knts with a whole lot more room in the boat, also done a couple of 22' north american from io to outboard worked great. gained speed in every instance i have done it. you just cant beat the power you get out of an outboard.
 

thurps

Chief Petty Officer
Joined
Jan 14, 2007
Messages
538
Re: I/O to OB conversion

The reason I was considering it was that I have a 115 Johnson and can get the boat and trailer, less engine and outdrive, for free. I thought I might be able to reinforce the transom and brace it to the engine mount stringers. Figured I'de end up with lots of fishing room and a washdown deck.
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: I/O to OB conversion

A single 115HP on a 24' would be very under powered, maybe if you had 2 of those 115's it would be a better idea. Even then it will cost a great deal to rig the boat, so even at free it will cost a great deal of money to convert it.
 

drewmitch44

Lieutenant Commander
Joined
Jun 26, 2005
Messages
1,749
Re: I/O to OB conversion

WOW!! I thought that Bond-o had experiance with boats and boating. Im new within the last 5-6 years to boating but ive seen a lot of nice boats that have been converted. Ive seen a couple that did now work out well but for the most part the ones that i saw were sweet! I dont even live in a big boating area but im 10 min from the delaware bay. I just thought that bond-o would have seen more boats as he's been here since before i have been here and ive seen a couple even right here on i-boats that have been converted and worked out. One guy i followed his project a coulple of years ago here on i-boats, and i dont know why but i didnt look at where he was from and it was funny but i saw him loading his boat at the ramp one day and we talked about stuff for about a half an hour. We talked about i-boats and how helpful it is and stuff like that. Small world!! I have learned a lot here. I have seen some pretty sweet conversions. Although i have never seen a OB to IO conversion. I dont think that would work out too well but im not going to just make a statement like that not knowing the facts like some people on here do. Happy holidays all!!
 

SuperNova

Lieutenant
Joined
Mar 16, 2007
Messages
1,455
Re: I/O to OB conversion

The reason I was considering it was that I have a 115 Johnson and can get the boat and trailer, less engine and outdrive, for free. I thought I might be able to reinforce the transom and brace it to the engine mount stringers. Figured I'de end up with lots of fishing room and a washdown deck.

You don't really need to reinforce the transom...just get the hole closed up securely and solidly. The transom is already thick enough and strong enough. If you really want to beef up the patch spot, thru-bolt a 1/8" thick stainless steel plate inside the transom, but even that is not really necessary if you fill the old outdrive hole correctly.

As far as expense...if you already have the engine and controls, all you really need is a jack plate and the materials to close the hole in the transom.

My only real concern would be your Coast Guard certification plate because you'd basically be recertifying the propulsion, but I don't know a whole lot about that end of things as my conversion was on an older boat and I didn't care about the cert. plate.

Ditto's to drewmitch44. Been wondering about some things myself.....ayuh
--
Stan
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: I/O to OB conversion

What frequently happens on these conversions, or when someone gets a boat like this for free without an engine and drive train, is they think it can be fixed up for little or no money. Then they find out that to replace a complete I/O is very costly, or you need to find a large outboard or two plus a bracket, which again will cost many $$$. In this case he's getting a 24' Reinell, they normally have a full cabin, which means it could be heavy. If thats the case, then a 115 won't be enough to push it very well, so he'll be looking for a bigger motor very soon and thats after spending all the money getting this one set up. And I'm sure this one doesn't have all the wiring and electronics in it, that's more money.

I see boats of this size and age advertised from $5,000 to $8,000 complete with everything, often with all the electronics, a rebuilt engine and outdrive, plus a trailer. While these may need a few things, you could use them right away.

As a project, and if you have access to the right parts, then there's nothing wrong with it. But if you thinks it's going to be a cheap way to get into boating, then it's not a good idea.
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: I/O to OB conversion

After my last post I checked Craigs List and found 2 boats right away.

A 26' Fiberform @$ 4,995 and a Carver @ $6,500. Both were in working condition with recent rebuilds, all of the electronics, plus other stuff thrown in.
 

thurps

Chief Petty Officer
Joined
Jan 14, 2007
Messages
538
Re: I/O to OB conversion

Thanks for the input gentlemen. I’m fairly handy with glass, mechanics and construction. I was planning on removing everything inside the gunnels and pretty much making it into a center console. I certainly know that nothing is cheap. I will give it some further thought but I’m getting tired of patching up my slope gliders and I really won’t have a life until fishing season opens in May.
 

Cptkid570

Ensign
Joined
Oct 18, 2005
Messages
967
Re: I/O to OB conversion

For the price of the jackplate, you could probably find a 19' boat and trailer with no motor...then you could just drop your motor on and go..
 

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
Re: I/O to OB conversion

If I were to do an I/O to outboard conversion, I would do it with a bolt on transom bracket like the ones pictured below. Everything I read about this style transom bracket is a plus: Additional floatation (some are hollow), better handling and ride because of the o/b is offset, as well as gaining back all that space the motor cover took up. Sorry for the big pics, they're linked in from another site.

walter15.jpg


brehm1.jpg


scott28.jpg
 

SuperNova

Lieutenant
Joined
Mar 16, 2007
Messages
1,455
Re: I/O to OB conversion

Yep Mark, those are exactly the kind of conversions I was speaking of as well.
Nice Pics!
--
Stan
 

thurps

Chief Petty Officer
Joined
Jan 14, 2007
Messages
538
Re: I/O to OB conversion

Mark42; Are those all custom built or after market products?
Thanks.
 

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
Re: I/O to OB conversion

Mark42; Are those all custom built or after market products?
Thanks.

Those are common after market products. Those photos are from customers at dadmarine.com check out their website and you should find the brands they install or just call them. The brackets I found are all aluminum and have drains in the bottom. They are not cheap, they run $1000 to $3000 dependin on the size and brand. But the best part is they are usually bolt on using stainless angle or channel on the inside with bolts going through to the bracket (a hatch lets you reach inside the bracket to attach the nuts) I like the the boat where they added a transom door. Neat touch and I'm sure it is very practical out on the water trying to drag in a tuna or other large fish.

I thought of making one myself out of plywood and fiberglass. Would have to be rather stout to support the stress, but I think it could be done.
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: I/O to OB conversion

I've started two conversions for myself and finished one. The first one, even with a free hull that was in very good shape, was going to cost far too much to complete. A big motor, a bracket and all the other stuff that goes into putting it together was going to cost far more than the same boat (used) was going to cost me and I could use it the same day instead of after months of work.

The second time around I made sure I had the right motor and all of the other stuff before I found the hull. It turned out very well and I still use it today.
 
Top