Aluminum angle for outboard mounting?

I bought a '99 Johnson 40hp that was converted to a jet drive.
I need to raise it up about 5" for mounting on my 20" transom.
I saw other boats where 2 pieces of 4" aluminum angle about 18" long
were bolted vertically to the back of the transom, and then the outboard
motor was bolted to the top of the angle pieces. This effectively raises
a jet drive of a long shaft up to where it should be on a 20" transom.

Before I start drilling, I thought I'd ask for any opinions on this setup.
Thanks.

Re: Aluminum angle for outboard mounting?

like this.

you can also reinforce it, with aluminum plate, like this. and use the angle.


or do a jack plate, just a couple of bends 3 1/2 inches. 3/16 aluminum. that is a '93 50 on the jack plate.

Re: Aluminum angle for outboard mounting?

Thanks for the ideas, and the drawings.

I am now thinking of your transom elevator design, somehow in combination
with what I saw. What I saw was 2 pieces of aluminum angle, T6061, of 4"
angle 5/16" thick, bolted vertically on the back of a transom. The Merc 115
was bolted at the top mounting holes only to the angles, and at the bottom
mounting holes through the angles and the transom. The bottom of the angles
were also bolted through the
transom. The angles were about 18" long overall. No filler 2" x 6" was used,
with trust in the strength of the T6061 angles for strength. Sorry I don't have a pic to show.
It works great.

It takes some thought to believe in the stength of the T6061 angles, and
I am still working on that, myself.

I have a piece of 4' long 4" angle 1/4" thick T6061 coming this week.
I figure if the 5/16" will handle the 115hp, then the 1/4" will handle 40hp.

My issue is that I think the motor should be over the actual transom, as it
is in your transom elevator. I don't agree much with the overhang of a heavy
motor, even if it's only 1.5". I'm going to somehow use the 2" x 6" in your
design, along with the 4" T6061 angles. I'll post a pic of whatever I do.

Thanks, again.

Re: Aluminum angle for outboard mounting?

i know the picture you are talking about, and is the silliest thing i ever saw, the transom elevator and the jack plate serve the same purpose. the jack plate is actually stronger that the elevator. but for what you are doing, the elevator is more than enough. these are all proven designs.

http://www.iboats.com/Marine_Store/...56859--submit.Search--submit.x.39--submit.y.6

Re: Aluminum angle for outboard mounting?

Well, I completed my mounting project, and I combined some feedback
suggestions with my ideas. I have attached a couple pics to show what I did.

I used a piece of outdoor 2" x 6", and an additional strip 1 1/8" to raise the
motor 6 5/8" total. The motor rests on this piece of wood, directly on the top
of the transom. It is fastened with 1/2" bolts to 2 pieces of 4" aluminum angles,
each 18" long, as shown. I also used the leftover piece of aluminum angle as a
spray plate, as shown. That plate very effectively minimizes any drag and
splash up from the intake. It actually directs water flow into the intake.

I used a scrap piece of luan plywood to create a mounting template by putting
it into the mounting bracket of the motor and drawing holes and lines as needed.

If anyone has questions, let me know.

How does it work? Fantastic!!!

Re: Aluminum angle for outboard mounting?

I see only the top two engine mounting bolts. That engine is intended to have the lower bolts installed as well. Otherwise, it looks like a neat installation.

Ooops -- didn't see the bolts above where the lower bolts are normally installed.

Re: Aluminum angle for outboard mounting?

nice clean job. just watch for the bolt heads, wanting to pull thru the wood,