Select the Correct Shaft Length for your Motor

Select the Correct Shaft Length

Choosing the correct shaft length for your trolling motor is important so that the electric motor does not cavitate, creating fish-spooking noise. The rule of thumb is to have the top of the lower unit or foot of the motor covered by at least 12" of water. In general, shaft length selection is more critical with bow-mount motors versus transom-mount motors. Most boat transoms are similar in their distance to the water, and Minn Kota’s standard transom shaft lengths should be adequate. With bow-mounted motors, there is a greater variation in shaft length requirements.

Measure for your Correct Shaft Length

Measure from the mounting surface of the transom or bow where the motor will be mounted to the top of the water.

  • Add 5" to waterline measurement for fishing in rough water. Optimal operating mode is with the engine trimmed all the way down.
  • Add 9" for bow-mount Hand Control motors. If you will be steering a hand-controlled motor while standing, add an additional 12" to the measurement.

Use this measurement for the tables below to find the appropriate trolling motor shaft length. For more information, visit our Trolling Motor Selection & Boat Size Guide and Rigging Guides pages.

Bow-Mount Shaft Length Recommendation Chart


Transom-Mount Shaft Length Recommendation Chart


Was this article helpful?
1428 out of 1546 found this helpful

Articles in this section