Engine Mount Trolling Motor Selection & Installation
Engine mount trolling motors offer great space-saving benefits but are also a bit more confusing that traditional bow mount motors. In this guide, we'll discuss how to pick the right sized motor, ensure it's compatible and install it to your outboard motor.
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Selecting the Right Sized Motor
Minn Kota engine mount trolling motors vary only by thrust, so you don't need to worry about selecting from different feature sets or series. The only real decision you'll need to make is how powerful of a motor you want / need. Minn Kota's engine mount models come in 55, 80, 101 and 160 lbs models.
Like all trolling motors, you boat's weight should be the primary factor you consider when selecting motor thrust. If you're unsure of your boats' weight, we recommend referring to the NADA boat directory which lists boat weights for thousands of different makes and models. When calculating a weight, make sure to include the weight of fuel, passangers, and additional gear.
Once you have a weight approximation, refer to the chart below to get an idea of what thrust level you should be considering:
Ensure Compatibility With Your Outboard
Unlike bow mount motors which bolt directly to the deck, engine mount motors are installed to the cavitation plate of your outboard motor. Due to the large number outboard motors - and they way in which they are mounted - it's a good idea to ensure your outboard will accomodate the engine mount model you pick. To determine compatibility, follow these three steps:
1. Check for 13" of Submersion
For an engine mount motor to work properly, the outboard's cavitation plate needs to be at least 13" below the waterline. This ensures that the motor will be submerged deep enough to prevent trolling motor cavitation, which can lead to reduced power and increased fish-spooking noise.
When measuring, it's very important to note the following:
13" is the MINIMUM: 13" is the minimum distance required for your motor to function well. If the distance is even an inch less - at 12" - there's a good chance you'll run into performance problems.
Measure UN-TABBED: When measuring, make sure your outboard is NOT tabbed (ie - it's sitting straight down in the water). You'll use your the trolling motor with the outboard in the non-trimmed position, so that's where you should measure it from.
2. Ensure Ample Mounting Footprint
After confirming ample cavitation submersion, you'll want to make sure your cavitation plate ledge is long enough to mount the motor on. Just about all cavitation plates should have enough length to support a motor, but it's always good to check. You'll want to measure and make sure that the cavitation plate has a 3" to 3.75" long ribbon (depending on the model of motor you'll be using - see chart below) on each side of the outboard spine where you can mount the motor.
Again, this shouldn't be a problem with most outboards and should be found on just about all models.
3. Check for Outboard Spine Clearance
The last compatability step is to ensure that the spine of the motor - the portion that sticks up in the middle of the cavitation plate - won't cause interference when the trolling motor is mounted. Engine mount motors are designed with a large gap in the middle to accomodate this spine, but you'll want to ensure ample clearance.
To do so, first fiind the rear mounting location by measuring back 3" or 3".75 inches (depending on the motor - see section #2 above) from the front of the cavitation plate. Then, measure straight up 7.25". As long as your 7.25" measurement clears the motor spine, you shouldn't have any problems.
For a better more visual representation, please see the two illustrations below.
Installing an Engine Mount Motor
The installation process for engine mount motors is fairly straight forward, and is as follows:
- Position the engine mount motor on the outboard anti-cavitation plate. Try to position it as close to the outboard as possible, sliding it back if necessary. The mounting bracket / legs for the engine mount motor may need to be flexed moderately in order to accomodate the outboard motor's spine.
- Holding the motor in place, drill six 3/8" holes using the hole pattern on the motor
- Insert the insulator pad between the cavitation plate and the engine mount motor
- Insert the six bolts and secure fro below
- Route the cable through the cable hooks and into the boat. Make sure to leave enough slack in the cable to allow for raising and lowering of the primary outboard engine.
- When finalizing the wiring, make sure to use the provided adhesive heatshrink to reduce the chance of corrosion