Extending Stringers

The only reason I said anything in this thread was because previous posters seemed to be more layed back about this conversion than I am. I am the one who is worried about a dangerous situation of over stressing a transom with an I/O to bracketed outboard conversion. I am not making assumptions. I am wondering how this can even be adressed on a forum without knowing the boat, the outboard, the bracket design, and the current state of condition of the transom.

Again, I love these conversions. I have watched many throughout the years on various forums. They are fun and make the boat better in many cases. But each conversion is different.

I wasn't saying your defintion of "sterndrive" was right or wrong, only that thats why I didn't understand your comment.

 

The transom is a standard approximately 1 3/4" thick. It was adequate for the sterndrive installation in spite of the large hole in the middle. The OP will block off the hole and laminate over the plywood. Further, the bracket will have less stress on the transom since the force will be distributed on a larger area. However, the OP has not said what outboard he is installing. If it is the same HP then my comment stands that it is fine without knees or other reinforcements.

 

I'm just probably going to put couple of knees to be safe.

No seating this is a fishing boat. You want to sit there is a bean bag for passengers. Maybe convert the space to a in deck livewell but thats way down the road when I like the weight distribution.

I'm probably going with a Suzuki 150 or 175. Main thing for me is availability.

On the Glasply forum someone with a 19 a repowered with a 200 and said he can push 40knts at WOT. I have zero need to go that fast.

I'd say most of the time I'm fishing in 6 ft seas and I can barely push 10knts now without breaking my back.

 

You are on the right track, the knees will stabilize the large flat area of the transom.
Some of the worst transom flex I’ve seen has happened when on the trailer, going over speed bumps!
Inspect the outdrive hole carefully for signs of water intrusion and rot, and maybe drill some inspection holes down below that.
The initial weight of the motor is only a rough starting point, it will be levered out on the bracket, and down the length of the leg. Varying and significant torque forces are applied, especially in rough conditions.
Overkill is your friend here,
I like to tie the gunnels across the transom as well, to stiffen the top edge.

 

Out drive opening is looks good so far. The paint or whatever they put it still there with no wood showing. Plan to grind that back before I close up the hole and will know for sure then.

I've already drilled through the transom in couple spots to check and came out dry. I have a feeling the transom might of been redone by a previous owner when the boat was modified. It did not come from Glasply like it is now thats for sure.

 

I had a brand new one many years ago, it was pretty poorly built, and I had to pull up the floor in just two years of use.
So your hull is VERY likely to have been made over, hopefully done right.
I’m a big fan of stretching the hull rather than hanging a bracket, the added waterline length is a big asset in rough waters.