O/B motor to boat

[azbew1211]

I am new to boat building (my first) and I am new to any type of internet forums like this.

I need to find how to mount a 90hp Evinrude O/B motor to my aluminum deck boat. The motor mount is essentially a 15 inch wide by 18 inch high frame made bolted and welded 2 x 2 x 1/4 angle. The last word I got from the designer, was to drill 1/2" holes near each of the 4 corners. I am assuming I am to bolt a hefty piece of wood to the motor mount with 1/2 inch bolts, but I don't have any idea of how thick the wood has to be.

I have called the boat's designer and the Evinrude dealer, but they have not returned my calls.

This is the latest in a long list of delays that pushed my "winter boat project" into my working in 110 degree Arizona heat. Can anyone help?

Newbie Boat Builder

97.7 KB file size limit for jpeg attachment prevents me from attaching photo. 267 KB is smallest file using the smallest and lowest quality readable photo of motor mount

 

[tashasdaddy]

Re: O/B motor to boat

cut 2 panels of 3/4 exterior grade fir plywood, the glue and screw together. then 3 coats of exterior oil based paint. then mount to frame.

 

[azbew1211]

Re: O/B motor to boat

Thanks for the quick reply.

Man, I really do not know how to get back to you with the photos. When I click on your name and get a message box, I don't see a place to attach files.

I do have another question. You said to coat with 3 coats of oil base. I asked at the hardware store, and thought that is what they gave me, but I put one coat on before reading the label that said it was exterior latex. Is this acceptable, or should I make a new mounting plate?

What is the best way to insure the holes will line up? The new motor is bolted to the crate with 4 bolts near the top, but below these are 2 very long slotted holes. Do I mount the motor using the same 4 hole as hold it in the crate, or do I need to bolt through the slots?

Thanks