How to Secure Your Outboard Motor for Safe Trailering

A frequent question of new sailboat owners is what do with their outboard motor when trailering. Is it best to leave it on the boat or is it better to dismount it and haul it in the boat cockpit or tow vehicle? There are lots of owners in both camps. In this post, I describe the pros and cons of each method and how I prepare Summer Dance to hit the road.

Some owners dismount their motors to prevent the weight from prying on the transom as they go down the road, especially for long trips. The main idea is to prevent damage to the transom. The disadvantage is the time and effort it takes every time you trailer the boat. Besides protecting the transom, another advantage is this lightens the load on the trailer behind the axle. That puts a greater percentage of the boat’s weight on the trailer tongue and can help stabilize the trailer at highway speeds.

I used to be in this camp. There are a lot of bumpy state highway and county road miles to where I sail. I used to lug my 87 lb. Yamaha outboard by myself from my pickup bed and lift it up onto the motor mount just before we launched. At the end of our trip, I’d lift it off, carry it to the truck, and lay it back in the bed. I can still do it, but it’s one more chore to do before I can launch and I’m not getting any younger.

Come over to the dark side

Other owners leave their motors mounted except to remove them for service or winter storage. The main idea here is to save the time and effort but you have to trust that the transom is strong enough to take the stress. Some owners reinforce the motor mount attachment to the boat with plates or brackets on the inside of the transom. Some secure the motor with ropes or straps to prevent it from pulling excessively on the transom. The disadvantage to leaving your motor mounted is the possibility of transom damage if you don’t take adequate precautions. Also, the additional weight on the aft end of the boat can make the trailer tongue too light unless adjusted for.

I now prefer this camp. Here’s how I do it with the confidence that I’m not damaging my transom.

Spread the stress

I fabricated and installed the aluminum angle brackets in the following picture inside the transom for reinforcement. A flat metal plate or board will help a little but it is more likely to deform and it doesn’t spread the stress out enough in the right direction, vertically. The perpendicular side of these brackets provides much more strength than the bolted side. It would take an extreme amount of force to bend these brackets to the point of cracking the transom. They’re similar to the motor mount transom backing rails sold by a certain online Catalina parts retailer but are made from scrap that cost me nothing.

Outboard motor mount reinforcements inside the transom
Outboard motor mount reinforcements inside the transom. They extend as far as possible above the upper bolts (out of view).

For extra protection against jarring bumps, I also secure the motor to the hull with 1″ ratchet straps attached to the aft mooring cleats. The port strap goes directly to the cleat nearest to the motor. The starboard strap leads forward and around the starboard sheet winch and then aft to the starboard cleat or pushpit stanchion.

Close-up of strap arrangement

The straps form a V shape that pulls the motor straight forward while they also secure it side to side. This transfers the weight that would otherwise pull outward on the top mounting bolts into downward vertical weight on the transom. I tighten both straps just until all of the weight of the motor is on the bottom arm of the mount and the top arm of the mount is loose.

Cockpit view of strap arrangement

Overkill? Maybe, but its cheap insurance and takes less time than mounting or dismounting the outboard motor. I adjusted the position of the sailboat on the trailer to maximize the tongue weight without exceeding the 7%-10% rule of thumb and it still tows straight and steady. After hundreds of miles, I have yet to notice any adverse affects from towing this way. 

Now it takes me less time to launch and retrieve Summer Dance and my back is spared from lifting and lugging an 87 lb. motor around. When I do need to dismount the motor for maintenance or winterizing, I lower it straight down onto my DIY outboard motor stand. Then I can easily roll it around to wherever I need it.

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10 Comments Add yours

  1. Tom Luque says:

    It a well known fact that your engine is a lot heavier at the end of a sailing trip. Or could it be that at the start of an adventure, your eagerness and freshness makes light work of everything?

  2. Paul says:

    When the boat is in the water I always have a safety line attached to the motor in case of catastrophic failure of motor mount etc.

    1. Tom says:

      I have just had the pad of my outboard bracket break across at the top row of bolt holes. If I didn’t have a safety line attached at all times we would have lost the motor. As it was we pulled it aboard and spent the rest of the evening working out how to replace it. In the end the stern thwart of the tender was canibalised to make a new pad.

  3. Ed Bachmann says:

    Do you have to worry about theft when leaving it mounted, or is there a reasonable security system/device that isn’t in the way when sailing?
    Thanks for the great tips!

    1. Hi, Ed

      Yes, you definitely do need to secure your outboard as much as possible when it’s mounted on your sailboat, when it’s on the trailer and on the water. A friend of mine had his nearly new outboard stolen right off the transom of his sailboat. They’re very valuable and easy to sell.

      Mine has holes in the clamp handles that accept a padlock, which deters the pettiest of thieves. I also have a stainless steel cable that tethers it to my mounting bracket and acts as a safety leach in case the motor somehow falls off the bracket and tries to become an anchor. But it would only take a few minutes with wrenches to disassemble the bracket and steal the motor with it still attached. I know this because I did it myself when I forgot the padlock key once.

      So do as much as you can to protect your investment and verify that it’s covered under your insurance policy in case the worst happens.

      Good question!

  4. Ed in Gig Harbor says:

    Another question, since I can’t seem to get the site menu to open on my devices for a search of your posts… Did you once do a post about using one’s mainsail boom to lift the motor so you could then move it to the side to lower it to the ground? I don’t believe that would work for my Venture 21; not without an extension of some kind for the boom.


    1. Hello, Ed

      No, I have written about that. My boom is also too short to lift the outboard straight up off the transom, as are most sailboats. However, that might work if you can get the motor into the cockpit and then need help to lift off to a dock.

      The same idea could be used to help recover a crew member overboard who needs extra help getting back aboard. On Summer Dance, I can unsnap the main sheet from the traveler, swing the boom athwartship, snap it onto a life ring that should be around the victim by then, and then haul them up with the main sheet tackle until other crew can help bring them into the cockpit. This might be particularly helpful for smaller crew members who aren’t strong enough to help an exhausted victim. If the main sheet doesn’t have enough mechanical advantage, I leave a long tail on my boom vang tackle that has a higher ratio advantage for that purpose.


  5. steven wallace says:

    Like all the info you post. The best to you.

  6. Kane Holland says:

    My understanding is that putting on the 4-way flashers plus headlights checks all the trailer lights? Am I mistaken?
    I keep the 4-pin connectors capped and coated in spark plug dielectric grease. No problems so far, touch wood. A half twist in the ratchet strap stops the insufferable droning.

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