Towing with outboard

[Popeye]

If you tilt the motor UP when trailering, the weight is more centered over the transom. If down, the motor is mostly pulling the center of the transom back when you hit bumps.

That being said, if your transom is solid, it probably doesn't matter much or at all, especially with a 50 or smaller motor, IF you have a 1-1/2" thick, 2 ply transom. Some transoms only have a pad on he outside, in which case, you should be more careful.

I have an aluminum tube transom on my Princecraft, so it really doesn't matter either way.

I would tend to agree with you about the weight being centered over the transom IF, there was no uppy-downy play. As the motor bounces up and down, it will also rock front and back and pull on the transom. That's where the transom saver comes in. It stops that rocking and wrenching action on the transom.

 

[thill]

Agreed. Bouncing is bad!

 

[Zum]

Ive never used a transom saver,currently have a 30jp 2 stroke.I figure if your boat sits on the bunks correctly, theres springs on the trailer, then why. I do bungy it to one side so it doesnt flop around and I can trailer it without tilting it.

 

[Coolvtfly]

Ive never used a transom saver,currently have a 30jp 2 stroke.I figure if your boat sits on the bunks correctly, theres springs on the trailer, then why. I do bungy it to one side so it doesnt flop around and I can trailer it without tilting it.

My thoughts on a transom saver is that it transfers the bouncing weight from the transom to the lower unit, not good. The torque that is placed on the transom by the outboard when used in the water might be more than the bouncing that occurs while trailering. With the transom saver you have metal bar directly connecting the lower unit to the axel with no give. However, if your skeg hangs below your axel you do need to find some way to raise it.

 

[airshot]

Stop the motor from bouncing or flopping around and you will have no problem unless you have a very small flimsy aluminum boat. How you go about holding the motor in that position is up to the owner....

 

[pathunter]

My thoughts on a transom saver is that it transfers the bouncing weight from the transom to the lower unit, not good. The torque that is placed on the transom by the outboard when used in the water might be more than the bouncing that occurs while trailering. With the transom saver you have metal bar directly connecting the lower unit to the axel with no give. However, if your skeg hangs below your axel you do need to find some way to raise it.

 

[pathunter]

The transom saver converts the motor shaft and transom from a lever and fulcrum to a solid triangle which is the strongest geometric shape. The Evinrude EL motor had a travel lock which supposedly negated the need for a transom saver. But that, in my opinion, only kept the motor from dropping down. Still wouldn't take the strain off the transom. Unless it held the motor in exactly the correct balance point to exert the force of a jolt directly down.

 

[airshot]

If the motor doesn't move, there is no force. How the motor hangs makes little difference, the transom is designed to support that weight. When the motor flops around, then you create excess strain. Keep the motor in what ever position you need to trailer and secure it in that position. How you secure it, is up to you, just make sure it cant flop up and down

 

[thill]

Well, to be accurate... there IS force exerted on the transom, even if the motor doesn't move around. It exerts a static force in general, and a sudden, kinetic force every time you hit a bump, which is multiplied even more if the motor is bouncing.


Static force is a product of gravity and is always there. If you have ever tried lifting a motor by the engine bracket, it will instantly flip over without support. Or look at a wooden motor stand that someone didn't build strong enough, and you will see that the motor wants to twist the mounting board tight off the stand.

Kinetic force, the force caused by motion, is much more powerful and destructive. A baseball held in your hand won't hurt, but throw that same baseball, and it dan do a lot of damage. Same thing with a hammer or a bullet. Speed plus mass.

On your boat transom, the static force of your motor constantly pulls your transom down and back, due to gravity. This is multiplied GREATLY when you hit a bump, and it multiplies even MORE if the motor can bounce up and down.

How much kinetic force occurs to your transom and what direction that force goes depends much on where the balance point is. If the motor is fully down, then the pressure will be down and back when you hit a bump, wanting to twist your transom off. But if the motor is up, close to the balance point, almost 100% of the force will be vertical when you hit a bump, the strongest direction for your transom.

This is simple physics. The softness of your tires and shocks are other factors that can mitigate the forces on your transom.

ALL THIS BEING SAID, as stated above, if a particular transom is designed to handle the weight of a particular motor, and is in good condition, there shouldn't be a problem, especially if you can trailer the motor tilted up, as close to the balance point as possible. The heavier the motor, the more these things matter.

This is not much of an issue if you have a 5 HP motor, but a much bigger issue if your tinny has a 90 HP 4-stroke.

 

[LaqueRatt]

Very informative Thill. Thanks for posting. I learn a lot from this site.