Yet Another I/O to O/B Conversion

[Reel Kahuna]

I didn't want to Hi-jack the other thread so decided to post my I/O to an O/B conversion.

Bought this Beachcraft by Reinell a couple of months ago that had a 4.3 OMC Cobra with 300 hours. The oild pan had a leak so I pulled the motor out to change the pan. Re-installed it, went fishing but the shifting was giving me trouble. Being that I may have had to pull the motor out to change the shift cable, I decided to convert to an outboard.

Removed the motor and outdrive

Then the hole was plugged using marine plywood and fiberglass (used the wife's camera so disregard the stamped date)

 

[Reel Kahuna]

Re: Yet Another I/O to O/B Conversion

Transom finished (again, disregard the stamped date)

Found a Gil Bracket on Craigslist. I mounted it to my boat using the dimensions for a 25" shaft motor

Although I was looking for a Yami with a 25" shaft with no success, I got real lucky and found a Yami 150hp with 20" shaft but with a CMC powerlift jack plate which will drop the motor down the 5" that's needed to have the anti-cavitation plate 3" above the keel.

 

[Reel Kahuna]

Re: Yet Another I/O to O/B Conversion

Prior to mouting the motor, I installed a 5/8" marine plywood inside the transom for added strength along with 3" aluminum washers. In preparation for adding stiffners to join the transom to the stringer, I pulled all the vinyl deck cover and to my surprise the deck was fiberglassed over from the factory.

Being that the weather forecast calls for rain for the next three days, I decided to work on the dash that holds the gauges. Went Taps Plastic and bought 6"x19" piece of plastic, drill the holes for the factory Yami digital guages but also decided to use a couple of extra gauges for the CMC power lift positioning, fuel gauge, volt meter and an hour meter which I'm still waiting for delivery.

Being that the Gil Bracket added another 2 ft, I still need to order a Teleflex rotary steering cable.

I'll post later as I make more progress.

 

[ondarvr]

Re: Yet Another I/O to O/B Conversion

Looks good so far.

 

[rolander]

Re: Yet Another I/O to O/B Conversion

Damn I cannot see the pics at work. Stupid firewall!!

 

[rolander]

Re: Yet Another I/O to O/B Conversion

Looked on my phone, I like the way you did your plate. Nice job

 

[MRS]

Re: Yet Another I/O to O/B Conversion

WOW, both you guys are doing a awsome job. I have a fourwinns 190 Candia with the cobra 4.3 runs excellent plus I just love the hull they have a conversion to merc. I thought if something bad ever happened to the cobra would do the merc stearn conversion because most say you can not go outboard on a stearn drive boat. But I did always want the outboard with a water pickup so I could run up the rivers....... Great job keep the updates coming.....

 

[eedwards]

Re: Yet Another I/O to O/B Conversion

Im sure the outboard weights less than the old motor, but have the outboard hanging that far off the back cause a problem?

 

[rolander]

Re: Yet Another I/O to O/B Conversion

Im sure the outboard weights less than the old motor, but have the outboard hanging that far off the back cause a problem?

I have had no problems with mine hanging off the back that far. I've been running my set up for about 8 years now with no problems at all. The boat plains out great, and performs great. In fact with the motor being behind that transom it's quiet as hell too. Get rid of that inboard motor and you have tons of room inside!!! I would do this again in a heart beat.

 

[Reel Kahuna]

Re: Yet Another I/O to O/B Conversion

Im sure the outboard weights less than the old motor, but have the outboard hanging that far off the back cause a problem?

My boat's transom is 2" thick but I too was concern about the weight being out that far so I'm fiberglassing in a couple of braces from the transom to the stringers. I'll also fiberglass in a couple of braces on each corners at the transom to the gunwales. I'll post pics later but here's what I've been working on lately...swim platform frame.

I also created some storage spaces for fishing tackle. I plan to fiberglass over them too.

 

[rolander]

Re: Yet Another I/O to O/B Conversion

Fiberglassing your transom is a waste of time bud, I just had an 1/8 piece of steel cut for the inside of mine that was as close to being the size of that whole transom inside and bolted it on, then bolted my 1/2 aluminum plate to the outside of the transom, then bolted my C drive to those plates. Mine has not moved or budged at all. No need to go through the work of fiberglassing if you want to save some work and itching LOL

 

[erikgreen]

Re: Yet Another I/O to O/B Conversion

Have you done any checking yet to see where your new center of gravity is? Like floating the boat to check trim?

Erik

 

[rolander]

Re: Yet Another I/O to O/B Conversion

With the 175 on the back of mine I am a little *** end heavy now. Not real bad but the rear of the boat does sit a little farther in the water then it did with the 140 on it. It's not enough of a difference to bother anything. The boat still planes fine and handles great. Just when your sitting in the water fishing the bow is a little higher then it was with the 140 on it. My 60" trolling motor still goes plenty far in the water to function perfectly.

 

[Friscoboater]

Re: Yet Another I/O to O/B Conversion

I am not a fan of these conversions, but you have done a nice job. There has to be some detrimental effects to doing this.

 

[Reel Kahuna]

Re: Yet Another I/O to O/B Conversion

We've experienced rotten weather with the rains and winds lately so it has slowed down my progress. However, I was able to take it out this morning for a shakedown cruise. Am quite please on how she handles. I still need to tweak a couple of minor things but will be ready to tow it up to the Colombia river gorge in Portland, OR next month for some oversize Sturgeon .

 

[rolander]

Re: Yet Another I/O to O/B Conversion

Good for you Seon!!!! Glad you got it out. how did it perform for you? How was your hole shot and overall handling and speed?

 

[reavesga]

Re: Yet Another I/O to O/B Conversion

Love the photos. My OMC just died. Looking at doing the conversion. One question is how to determine the heigth of the transom? I am thinking about actually cutting my stern and building a splash well. Need to know how high it should be for a 20" shaft or 25" shaft. Is the 20" number the actual heigth of the transom?

 

[Reel Kahuna]

Re: Yet Another I/O to O/B Conversion

Here's a link that may help you http://www.smalloutboards.com/shaft.htm . I'd recommend that you use a jack plate so that you can raise and/or lower your OB accordingly.

Sorry to all for not posting a follow-up.

My son and I towed the boat up to the Columbia river last June. I caught an 8-1/2' Sturgeon and the following day, my son caught a 7'+ Sturgeon. We were suppose to fish the entire week but had to return earlier on third day. Just as well being that each of us was tired from the fights.

Boat handled well. It certainly gave us plenty of room without the I/O taking up space. The hardtop sheltered us from the drizzles and unexpected downpours .

Since returning home, I've taken the boat out in the Sacramento Delta several times and again, it handled well, rock solid and comfy.

I can't find any downside to the conversion. I highly recommend it to anyone that's thinking of converting their boat.

 

[Kiwifisher]

Re: Yet Another I/O to O/B Conversion

I am not a fan of these conversions, but you have done a nice job. There has to be some detrimental effects to doing this.

Everyone to his own. However, I don't know on what facts u base your statement. Here in New Zealand it is common practise to do this conversion. I have exactly the same setup. It's been running good on 4 years now. Boat is very stable at speed, in the corners and in rough water. It does not sit deeper in the water like rolanders do( i would guess his is weight related)

It also free's up a HUGE amount of deck space for fishing.

These Gil or C brackets are so popular here, I've seen new boats with them on.

 

[Rich Hargis]

Re: Yet Another I/O to O/B Conversion

Nice job,I am a big fan of the conversions myself. Considering my boat had the OMC stringer drive,it was a no brainer to convert it to outboard than dump money into a pile of junk. Here is a link to my conversion for anyone who has thoughts about doing it.

http://forums.iboats.com/showthread.php?t=262606&highlight=wellcraft+makeover