1.5 Shaft length of an external border

The shaft type or length is usually specified by the manufacturer of your boat. If you cannot find any information about it, that's not a problem! You can easily determine this yourself. To do this, simply measure the height of your motor transom.

The height of the motor transom is the distance between the bottom edge of the boat hull and the top edge of the motor transom where the motor is hung. In the graphic, you can see which area you need to measure for this purpose.

Most sport boats require a normal or long shaft. Super-long and ultra-long shafts are seen much less often, mostly only on sailboats. Basically, choose a longer shaft rather than one that is too short. Many of the sterndrives also have a height-adjustable shaft so that the depth of immersion can be optimally adjusted. The larger outboards still have a trim for fine adjustment.

For a shaft length up to 38 cm (15 inches), a normal or short shaft is required. Beyond that up to 51 cm (20 inches) a long shaft is used. Up to 64 cm (25 inches) a super long shaft is offered and for everything else an ultra long shaft with 76 cm (30 inches) is used. We have summarized the values for you in the table above again.

Ideally, the anti-ventilation plate is 0-30 mm below the keel. If the engine does not have an anti-ventilation plate, it must be ensured that the propeller is under water at all times and does not "pull" air. If the propeller sticks out of the water when sailing, the engine may be damaged in the short or long term.

Fishing motors are often called the models with power less than 2 kW. Their shaft length is usually variably adjustable. However, there are also short shafts up to 66 cm. However, the most widely used are the 91 cm long shafts. The engines are mainly used in inflatable boats, sports boats or small sailboats their application.

Market leader here are the engines from the manufacturer Minn Kota, beyond that there are many more. Somewhat cheaper and still highly recommended are the e-motors from Haswing. The comparability of the e-motors is rather difficult.

It is important that there is no ventilation during the ride, so the engine "pulls air"! If the engine s not optimally in the water, there will be performance losses and increased wear.

Stern motors have a shorter shaft length than bow motors for the same boat. Using the illustrations and the two tables, you can very easily determine the required shaft length for your boat. If you still have questions about this, you can also call us at any time.