A transom saver is a removable bracket used to steady an outboard motor on a boat being hauled on a trailer. One end of the transom saver has a V-notch and a strap to fasten to the lower unit of the outboard, and the other end attaches to the trailer frame or clips to the trailer's aft keel roller. This keeps the weight of an outboard motor from stressing the transom while driving over bumps in the road. Constructing your own transom saver is a money-saving project.
Study units on the Internet. Most are highly adjustable to fit a wide range of boats. Yours can be created to simply fit your own boat. Tilt up your motor with the boat on the trailer and look at the boat transom directly under the outboard motor. If there is a keel roller, frame member or cross beam visible, this is within the scope of a do-it-yourself transom-saver project. If not, the trailer might need some modifications to allow use of a standard type of transom saver.
With the motor tilted up just enough so that the front of the gear case is even with the bottom of the boat, measure the distance between the roller and the leading edge of the motor's skeg, just above the rounded gear case. This will be the primary transom-saver length. Also, measure the width of the skeg just above the gear case. This will range from 1 to 2 inches.
Purchase a pressure-treated 2-inch by 4-inch by 8-foot-long stud. Also required are three galvanised or heavily plated 1/2-inch by 13-threads-per-inch by 6-inch-long square U-bolts with bottom plates or brackets, six 1/2-inch locking nuts and washers to fit, and two ratcheting 1-inch-wide tie-down straps at least 6-feet long. A compound electric mitre saw also will be useful for this project.
Add four inches for small motors, six inches for medium motors, eight inches for large motors to the primary length measured above. Cut two pieces of the wood stud to your calculated length. For example, if the primary length is 22 inches, and the motor is medium-sized, cut two 28-inch pieces. For large motors, cut two 30-inch pieces, and one 24-inch piece to sandwich exactly between them to compensate for the greater skeg width. Take the two larger pieces, and mitre cut the motor ends to 45 degrees along the 4-inch dimension. Hold their 4-inch faces together, and the mitre cut-ends should form a V. Clamp them with the U-bolts, and tighten securely. Cut a V-notch in the roller end with a handsaw or reciprocating saw in the opposite orientation from the boat end so that the notches are 90 degrees to each other. The distance between the bottom of both notches should be the primary length. Sandwich the shorter piece in the middle if necessary for very large motors.
Raise the motor, insert the transom saver in place under the motor and over the roller, and lower until the motor's weight holds it in place. Ratchet a tie-down tightly around motor, transom saver, and roller. Cut off any excess strap over 6 inches. Melt the end of the cut strap to prevent fraying. Keep the other strap as a spare.