Selecting the right motor for your boat is important. The wrong motor may not have enough power or have too much power, the shaft could be to short, or you may not get all of the features you are looking for. The Trolling Motor Selection Guide above will walk you through the available features for trolling motors and then recommend the best motor(s) based on your choices. It will also give you the information you need for the motor and recommended accessories for the best boating experience.
Jump to:
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Select the Correct Shaft Length
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Speed vs Thrust
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Freshwater vs Saltwater Trolling Motor
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Brushed Motor vs QUEST Motor
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Bow-Mounted vs Transom Mounted 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.
Click here for Shaft Diameters and Shaft Specifications for Minn Kota Motors
Bow-Mount Shaft Length Recommendation Chart
Transom-Mount Shaft Length Recommendation Chart
Speed vs Thrust
- Speed is how fast something is moving. For a trolling motor speed determined by a factor of prop pitch and motor RPM
- Thrust is simply a static measurement of pushing or pulling power, and higher thrust does not necessarily mean greater speed.
Calculate MPH
Given motor RPM under load, and Minn Kota’s 4" prop pitch, the approximate speed that a motor will push/pull a small boat can be calculated with the formula:
prop pitch in inches, times motor RPM, times 85%, (factor for prop slippage), yields calculated inches per minute. This value divided by 12 equals calculated feet per minute. The feet per minute times 60 equals calculated feet per hour. The feet per hour divided by 5280, (number of feet in a mile), equals the calculated miles per hour.
Example: ((4 x 1540 x .85) / 12) x (60 / 5280) = M.P.H.
For more information, click here to download our Runtime, Speed, and Horsepower Formulas Chart.
Determine Thrust Requirements for your Boat
Thrust requirements are determined by the size and weight of your boat. We suggest selecting a trolling motor with at least 2 lbs of thrust for every 100 lbs of boat weight when fully loaded. This guide is established under normal lake fishing conditions. If you frequently fish in heavy winds, rivers or adverse weather conditions you may want to consider a higher thrust electric motor.
Example: 2,000lb boat = (2000lb / 100) x 2 = 40lbs of thrust (minimum)
Rigging Guides
Click here for more information and downloadable Rigging Guides.
Freshwater vs. Saltwater Trolling Motors
Freshwater Motors
Designed for all kinds of freshwater boats, our motors offer the most intuitive controls, advanced technologies and unparalleled durability in fishing. Using any of our freshwater Minn Kota motors in saltwater may dramatically reduce the life of the motor and voids the manufacturer's warranty.
Saltwater Motors
We designed a special line of motors for use in salt or brackish water. The Minn Kota Riptide trolling motors have a number of "saltwater-engineered" enhancements, including stainless steel hardware, sealed electrical connections and an advanced painting process for improved corrosion protection. To extend the life of your Minn Kota Riptide saltwater trolling motor, thoroughly rinse the motor with freshwater after every use in saltwater and store indoors. Never leave the motor submerged in saltwater when the boat is moored.
Brushed Motor vs QUEST Motor
Brushed Motors
While the Quest motors are only available on select models, the Minn Kota brushed motors have a wider range of thrust options from 30 lbs of thrust up to 112 lbs of thrust. This wider range includes 12 volt options perfect for smaller boats with less room for additional batteries. Our brushed motors are also available as transom mount motors and as bow-mounted hand-tiller motors for saltwater.
QUEST Motors
We have taken the world’s greatest trolling motors and redesigned them to outperform anything else for years to come. With a larger & stronger mount to accommodate extra thrust and torque, new motor controller, and software changes have made it the most power efficient motor on the market. The new battery monitoring system gives you real time monitoring of power and automatic power saving mode when batteries reach 20% charge.
Bow-Mounted vs. Transom Mounted Motor
Bow-Mounted Motors
Boats do not tend to go in a straight line. Because of this, it is much easier to pull a boat than to push a boat. It is also easier to move the bow of the boat sideways compared to moving the transom. Therefore, a bow-mounted electric trolling motor allows for much greater boat control and positioning. If quick-response boat control and positioning is what you are looking for, a Minn Kota bow-mount electric trolling motor is a must.
Transom-Mounted Motors
Transom mount motors mount to the back of the boat with a clamp-on bracket and feature hand/tiller control. They are ideal for smaller boats, dinghies and canoes. They are also great for general positioning and standard trolling.
