Adding an outboard to an O'Day 25

[Project_Mayhem]

Call me paranoid but I'd like to add an outboard as a backup to my 41 year old Saildrive. How much wood should I add to the transom? Do most O'Day 25 owners find the need for a tiller or shift extension when using a typical long shaft motor?

Also, I'm trying to decide between a 15-25hp or a smaller 4-7hp. How hard is it to drop the larger one in the water in the event of an emergency (it will live on the motor mount)? The smaller one might be useful in the rare case that I want to use it on my dinghy

 

[JRT]

Depends on if you have a solid transom, ie no rot. If you have a solid transom then the max size is really driven by weight, When I looked at this originally the boat was designed around a 2 stroke motor, but the 4 strokes are better with less hp and weight. I love my Tohatsu 6HP Sailpro 25" shaft outboard and it works great. No way I
d put a 15-25 hp on my O'Day that is a lot of weight and the transom will suffer without more reinforcement and weight.

https://onlineoutboards.com/collect...atsu-6-hp-mfs6csproul-sail-pro-outboard-motor

 

[Timm R Oday25]

We've sailed our Oday 25 for 15 plus years on Lake Michigan . Originally we used an ancient Mercury 7.5 .
Currently we use a Johnson 8 horse 2 stroke with an extra long shaft 25" .
Even a 6 horse four stroke will weigh considerably more .
I would not use a standard long shaft of 20" as the mounting plate would have to be mounted very low and close to the water .
The outboard would be even harder to start and turn. We normally just snug up the steering pivot knob and leave it pointed straight ahead.
Great care must be taken if you are motoring and turn the tiller/rudder so it doesn't hit the prop.
Bad sounds will come from it . Trust me on this

 

[Project_Mayhem]

I had the same issue on my Starwind 19. The solution was to cut a larger mounting board so the outboard got moved a few inches away from the rudder. There are other more elaborate solutions but this one was quite simple. I'd prefer to stick with 2-stroke so both engines could use the same fuel

 

[JRT]

Well I had a 1984 Mercury 2 stroke with electric start, 2 cylinder, the weight was 65lbs, the replacement Tohatsu is 61 lbs. Honestly I don't have a dog in this anymore, I gave my feedback based on my research, my decision and what I did and really like. Giving up the electric start was just fine to me because the Tohatsu starts so easy and just pushes the O'day back home with no fuss or muss.

 

[Project_Mayhem]

I have a 4hp Tohatsu that will be sold with my 19 footer. It would work as a backup in calmer conditions but even on the 19' it took a while to stop it. So much so that I started backing up from my slip to the main "isle" of the marina.

I know the transom should be reinforced but my question is how much plywood should I put there?

 

[Timm R Oday25]

The transoms were not the heaviest built . I used marine 3/4" glassed into the inside . Worked very well.

 

[Ron20324]

PR, is the transom curved or flat?

 

[Timm R Oday25]

It’s slightly curved . I cut vertical slots in the wood about 5/8” to allow it to follow the contour

 

[Project_Mayhem]

The transoms were not the heaviest built . I used marine 3/4" glassed into the inside . Worked very well.

Did you just add a small portion of wood or go across the entire stern?

 

[Timm R Oday25]

I reinforced the complete stern from the inside . This also allowed me the opportunity to redo the pintles and grudgeons for the rudder at the same time . The stern boarding ladder also benefitted from having a larger stronger thicker backing plate .