Outboard motor attachment issue

I have recently installed a Torqeedo electric motor model 1003L on my Portland Pudgy dinghy and find its attachment is less than optimal. The screw clamps are far to close to the top of the transom as shown by this picture below.



As you can see, the clamps are very close to the top of the transom. I'm concerned that when applying max power of the motor it may just try and twist itself off. As I apply power I can feel the motor mount twisting some. The backside of the transom is not shown in the picture. However, here's a picture of the mounting structure/bracket below. It has raised horizontal ribs and this surface will fit parallel to the backside of the transom.



Everything tells me that the motor should not twist off if the rear surface of the bracket with the horizontal raised ribs fits snugly against the rear surface of the transom.

...but nonetheless I'm nervous those front two clamps may simply not have the holding strength resulting in me losing the motor overboard.

Hopefully you will admit those clamps are simply far to close to the top of the transom lip.

Is there a solution to this I ask ?

I think the motor will be fine. Though the installation is not idea, when the clamps are tightly secured, they should be fine. These electric motors do not have the sudden torque that a gas powered outboard has. My boating buddy has a torpedo motor on his port-a-boat and the acceleration is perfectly adequate though not the jack-rabbit potential that a conventional outboard has.

For piece of mind, you could attache a tether line from the motor handle or mount to an eye bolt or something similar in the event the motor left the transom mount. If I could not live with the mount as it is, I would mount a piece of 3/8" starboard on the inside of the transom, that covers the area of the engine mounting bracket, and cut out material where the screw down mounts are. The result would be that the mounts would be slip into the hole of the starboard thus preventing them from rotating off the transom.

The problem is that the footpad of the t-bolt screw is partly off the metal backing plate... Given the gap between the inside of the C-clamp and and the backing plate, my knee jerk reflex would be to get two pieces of SS, 1" wide by 5/8 thick by 2.5" long... Drill a countersunk hole to bolt it to the inside portion of the C-clamp where the T-bolt screw now resides (remove it obviously)... Then drill and tap the lower end of the SS piece to match the threads on the T-bolt screw and reinstall it there... That moves your screw down far enough that the foot pad is completely overlapped on the metal plate and should eliminate twisting...

Levitation: I assume SS = Stainless Steel

Thanks for the idea.

j&lgray:

Thanks for the reassurance... I like your idea from a simplicity standpoint.

The Torqeedo model 1003L (long shaft of 28") has a max static thrust of 68 lbs. This means a moment force of some 68 x 28 = 1904 in-lbs at the transom's top edge. The Portland Pudgy does has reinforcement on the transom's inboard surface by way of a grey metal plate as seen in my photo. This should help resist the moment force.

I will be satisfied if I can convince myself the clamps simply cannot slide up and over the transom's top edge and your soln should provide this.

Bill,
I looks to me like you could tip the motor forward until it clears the upper part of the transom and then tighten it. I could be wrong or the photo could be misleading.
Bob

Nellie Too":zei1ts5d said:

Bill,
I looks to me like you could tip the motor forward until it clears the upper part of the transom and then tighten it. I could be wrong or the photo could be misleading.
Bob

Click to expand...

Yes -- I tried that but it means the backside of the C bracket (the face with the horizontal raised ribs) does not align flush with the outboard side of the transom. This surface needs to be flush with the transom to avoid any flex when the motor is running. Thanks for responding to my post. 🙂

Hi Barry,
I am very sorry I callede you BIll, a senior moment. I was thinking you could insert a piece of hard rubber or something like it under the motor head against the transom to absorb the forward thrust. Just an idea.
Bob

baz":1fc653bo said:

Nellie Too":1fc653bo said:

Bill,
I looks to me like you could tip the motor forward until it clears the upper part of the transom and then tighten it. I could be wrong or the photo could be misleading.
Bob

Click to expand...

Yes -- I tried that but it means the backside of the C bracket (the face with the horizontal raised ribs) does not align flush with the outboard side of the transom. This surface needs to be flush with the transom to avoid any flex when the motor is running. Thanks for responding to my post. 🙂

Click to expand...

If the clamp screw pads landed on the backing plate when tipped forward as Bob suggested, I would make a hard wood wedge that would fit between the aft side of the transom and the motor mount. Added benefit would be that the motor's weight and thrust would be spread over a larger area then just size of the mount bracket. Just a thought.

Brian