80's Sea Ray Inboard to Outboard Conversion.

[kashurst]

I think looking at the construction of the box the outboard mounting plate needs reinforcing at the top. There is a risk it could be pulled off backwards. Could you add say two stainless threaded rods and basically bolt the top edge or the engine mounting plate to the opposite facing side of the box. Then the engine mounting plate cannot be twisted off backwards. (does this make any sense?)

 

[dpb]

At last I was able to test the conversion on the water.
I ended up with a 15hp Yamaha 4 stroke from 2009. It has electric tilt.
Mounting was straight forward though the steering arrangement needed a bit of fabrication and adaption.
Extra struts were added above the platform to resist upward movement in reverse as well as when bouncing on the trailer.
Main concerns were that the engine might sit too low in the water and that the power would be inadequate.
The trial went very well in the end.
The engine height is fine, much higher than I feared, and the speed was a very pleasant and useable 8mph at 3800rpm which is the current WOT.
Spec WOT is 5500 +/- 500rpm. The current prop is the longest pitch available at 12in. The shortest is 9in (I think) so will think about wether it is worth changing.
The only other problem is that the steering cable clamp arrangement is flexing so a mark 2 version is required.
The structure of the adapted platform seemed solid in use.

 

[simonfraser]

Great conversion, was tempted to do the same with my previous inboard mobo

But would have had to pay the yard as I don’t have the skills / space to do this

 

[vas]

nice result, would really expect the mk2 steering arrangement to scrap the fancy L shaped rod and bring the steering cable mount closer to the engine, should eliminate slack and issues...