The transom or motor mount
Transoms - Motor Mounts - Motor Pods
Fixed with wooded board
Modern all aluminum with gas tank
The motor mount or transom is what supports the engine. Older transoms were not a long as newer ones and most had a piece of 1 1/2” wood to support the engine. Twenty years ago most manufacturers switched to all aluminum transoms. The piece of wood was replaced with a thick piece of aluminum to support the engine. Pontoons with wooden transom boards should be inspected yearly for rot. There’s nothing worse than launching for the first time in the season and having the thrust of the engine break the wooden transom board. Although if the engine falls into the water that could be worse.
The transom to the left is attached to three cross members. There is reinforced bracing in the back of the boat. The transom on the right attaches to six cross members. The more cross members the transom is attached to the better it distributes the weight and the thrust of the engine.
An adjustable transom was popular years ago when pontoons used 20 HP engines. You could use a short shaft engine and in shallow water you’d raise the engine by pulling up on the lever. (early trim and tilt).
Modern triple tube pontoon boat sometimes have the motor pod as a part of the center pontoon. Other brands may have a traditional transom with the center tube bolted in front.
A word of caution to re-builders
Rebuilders occasionally find old boats with adjustable or small transom’s and want to use larger horsepower engines. Adjustable transoms won’t support the weight of many modern engines and you could create too much thrust on a weak older transom. You may have difficulty replacing an old transom with a larger one. You must consider the diameter of the pontoon tube. Adjustable transoms were used on 19” or 21” pontoons. If you replace a transom on a smaller diameter pontoon, you’ll need a transom for those size tubes. A transom for a boat with 21”, 23” or 25” pontoons might not work. The engine will sit too high. Replacement transom can be difficult to find and locating one that properly fits an old boat can be difficult. New boat builders are usually the only source for a replacement transom. Current production is almost exclusively for 23” to 27” pontoons.