Mounting an Electric Outboard on Rudder Fittings

There is no perfect solution for mounting an outboard motor on a small boat; it must be tailored to the boat and the needs of the sailor. Modifications to any of my boats must be aesthetically pleasing as well as functional. Aesthetics and functionality need not be in conflict, and in my case, the motor is not used enough to warrant the weight and complications of having it permanently mounted on the transom. Recent advances in electric outboards have allowed for options not practical for heavier and bulkier gas-powered outboards.

My Torqeedo 1003 is about 10 years old and has been adapted for several boats. It was originally used on AUNT LOUISE, a William Gardner–designed Eel. For this double-ender, the motor was mounted on a bracket attached to the side of the hull; it could be quickly removed and stored once under sail. AUNT LOUISE sold without the motor and, not having a small skiff in my fleet, I decided to see if the Torqeedo could turn my sharpie into a serviceable power skiff.

Photographs by the author

MALU’s rudder is mounted on two pintles on the transom. To make use of those pintles, the motor mount has two drilled-out Delrin blocks, which are bolted to a teak board and serve as gudgeons. Below the upper gudgeon, I through-threaded a bolt that will prevent the board from rising up and off the pintles.

MALU, my 17′ sharpie, has a transom but it also has an afterdeck that prevents simply clamping the Torqeedo to the stern. To avoid modifying the boat, I made a motor mount that fixes on the rudder pintles. I fashioned it from a teak board onto which I bolted drilled-out blocks that serve as gudgeons to the boat’s pintles. The mount sits snugly against the transom, cannot pivot, and rises above the transom to achieve the correct height for the long-shaft motor. With a long tiller extension that allows me to keep my weight well forward, the boat becomes a handy utility skiff.

Using the existing pintles works perfectly for my use of the outboard on this boat. But if you wish to use it on a sailboat where the rudder is not easily shipped and unshipped, you could fit a second set of pintles or gudgeons mounted to one side of the existing rudder hardware on the transom, making sure to offset the motor enough that it does not interfere with the rudder.

Because bad things can happen and a motor can be dropped on its way on or off the mounting board, a safety line is attached to the motor and connected to the boat.

Making the Mounting Board

To make the gudgeon blocks, I used Delrin, a dimensionally stable high-strength plastic that is easily worked using woodworking tools. Other high-strength plastics, or a good hardwood block, would also work, provided you take proper precautions to prevent splitting. The fabrication is quite simple. All that is needed is a hole drilled to match the diameter of the pintle. The center of the hole should be the same distance from the edge of the block as the center of the pin is from the boat’s transom. It is important to have a snug fit, with no rocking movement when the board is in place. Another solution would be to use a manufactured gudgeon bolted to the board, with blocking down each side to keep it parallel and fit tightly against the transom. If installing a set of pintles and gudgeons to use the motor on a sailboat without having to remove the rudder, mount the gudgeons on the boat and the pintles on the board—this will avoid having the more obtrusive pintles on the transom when the outboard is not in use.

Once the motor is mounted to the board it’s important to keep it there. The simplest way to prevent a motor from working its way off the board is to create a recess for the screw pads. This recess can be two indents, made with a Forstner bit (as seen here), for a specific motor or a single larger area suitable for a range of motors.

It is always important to make sure both mount and engine stay attached to the boat. First, just like securing the rudder, you need to prevent the mount from lifting off the pintles. I threaded a bolt through the mounting board just below the gudgeon. If the mount begins to rise up, the bolt prevents the pintle from lifting out of the gudgeon and keeps it securely in place.

After making sure the mount will stay in place, we then need to ensure the motor stays connected to the mounting board. Perhaps the simplest solution is to create a recessed area for the screw pads to fit into; this will prevent the motor from “walking” off due to vibration or simply because the screws have not been sufficiently tightened. You can make either two recessed holes to fit a particular motor or a recessed area for more universal use. While I chose the former, a larger recess could be created by routing out a small area, or simply by adding a block or cleat above the screw pad area. Finally, it is always a good idea to attach a safety line to the motor, for retrieval if the unexpected happens.

The Torqeedo motor is free to turn for steering while the board mount, fit snug against the transom, remains stationary.

Francis Herreshoff is often quoted as saying, “Simplicity afloat is the surest guarantee of happiness.” It could also be said that simplicity afloat is the surest guarantee of safety. Having your gear and systems set up to be easily accessed and deployed makes for a successful, enjoyable day on the water.

A lifelong resident of Florida’s Gulf Coast, Michael Jones spent his career as a boat carpenter working on the full spectrum of yachts from traditional to high-end luxury cruisers to sportfishing boats. Past president of the Traditional Small Craft Association he is a collector of small craft and is, he says, “still (boat) crazy after all these years.”

Putting the Pintles on the Board and Not the Boat

Notes by Christopher Cunningham

Michael’s sharpie, MALU, has pintles on the transom, so his motor-mounting board required fixtures with holes—the equivalent of gudgeons. All my rudder-equipped boats have gudgeons on the transom, and so, instead, require some sort of pintles on the mounting board.

Michael’s homemade gudgeons could be converted into a pintle by driving a short length of brass, bronze, or stainless-steel rod into a hole drilled to give it a tight fit in the block. Delrin would work well, as would a dense hardwood that’s not prone to splitting. I used a piece of local honey locust, a wood that I often use for making cleats. The hole for the metal pin is located to match the distance between the face of the transom and the hole in the gudgeon. To keep the motor-mounting board from swinging as a rudder does, the block is sized to fill the space between the transom and the rudder fitting. To taper the pin, I chucked it in a drill and spun it against a grinding wheel, then a 1×30 belt sander with a fine grit, and finally a buffing wheel. Note the cross cleat at the top of the board. Like the circular depressions in Michael’s board, it serves to keep the motor from slipping off.

One of the gudgeons I have, a commercial model made in cast bronze, has its hole very close to the surface on which it’s mounted, and I wouldn’t have confidence in a motor-mount pintle installed so close to the edge of the block of wood. A metal pintle would be stronger and, while commercial transom pintles aren’t as common as rudder pintles, they are available. I opted instead to make a pintle out of bits of brass joined by brazing them with silver solder. (See “Fillet Brazing for Custom Boat Hardware.”) To increase the space between the pin and the strap, I added a short piece of brass stock between the two elements and brazed all three elements together at the same time. Using a metal pintle requires adding a block of wood above the pintle to keep the motor-mounting board from pivoting.

On three of the boats for which I made rudder hardware, I avoided the challenge of making pintles by fitting gudgeons on both the rudder and the transom. A single brass rod inserted through all four of them holds the rudder in place. This method can have the advantage of keeping the rudder from lifting off by having the gudgeons on the rudder side flanking those on the transom side and would also work for the motor-mount board.

Christopher Cunningham is Small Boats’ editor-at-large.

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