How to Mount Trolling Motor on Aluminum Boat

By Brett Freese
February 3, 2022

Mounting a trolling motor on an aluminum boat may require different parts than on a fiberglass or wooden boat. Aluminum boats are popular for their durability and low price, but if your aluminum boat is not equipped with the correct base to mount your trolling motor you may need to modify some of the original equipment or purchase additional items before installing it.

We will show you the necessary steps and requirements to mount your trolling motor on your aluminum boat.

The first thing you need to do is go over the original equipment and see if your boat has a base or not, some boats will come with one pre-installed but most of the time you will need to purchase it separately in order to mount your trolling motor. This is because manufacturers prefer selling an assembled package instead of selling the boat with all necessary parts for mounting it.

If you are buying a base keep in mind that there are many different types, some bases can be used on both transom and horizontal surfaces while others are designed for only one type of surface. This kind of information should be available at the store where you are making your purchase so read carefully all descriptions that provide this kind of information before buying anything.

If you are planning on using your trolling motor at least once or twice a week, you should choose the one that has the best shock absorption system. Aluminum boats are lighter than fiberglass and wooden ones so it is very common for them to move around as they hit small waves with no resistance from the water.

This type of motion can cause damage not only to your boat but also to your equipment, especially if it is mounted on a thin platform that will easily crack under pressure from sharp movements.

Tools to Mount Trolling Motor

Drill (for Bow or Engine Mounted Trolling Motors)

This is one of the main tools that you will need if your aluminum boat has no base for mounting your trolling motor.

The drill is used to make holes at predefined locations on the deck or hull of the boat where the trolling motor bases are attached. There are two different ways for this purpose, with either a bow mount or an engine mount configuration.

Bow mounts are placed behind the boat, these types of motors are normally used when covering long distances and they move very slowly around 10-15 mph. You may also attach it to a transom but keep in mind that larger motors should only be mounted on sterns and transoms while smaller ones can go both on bow and sterns

Engine mounts are mounted right above the engine of the boat and they are mainly used for troll fishing, this type of motor normally goes faster than bow mounts at around 18-25 mph. They can also be attached to a transom but keep in mind that you should not install two trolling motors on aluminum boats because it may damage the engine or other equipment on your boat.

The base of both bow and engine mounts is built to fit perfectly with the holes made by the drill. Most of them come with predrilled holes and all you need to do is make some small adjustments before you tighten down the bolts. Be careful when using this tool because if not handled properly it can cause serious injuries or even death while performing this kind of task.

Hex Wrench Set

This set contains 6 standard-sized wrenches with different holes on the end, also called Allen keys. They are required for mounting the trolling motor base to your boat. Some bases come with predrilled screws so all you need to do is tighten them down by turning the wrench clockwise until they are secure.

However if your base does not have any pre-drilled holes, you will have to drill them yourself manually using a power drill. The holes that you will make should be about 1/4 inch (0.6cm) away from each other and on different sides of the base, both on top and bottom sections. These types of holes are standard on most trolling motor bases but some manufacturers may require longer drilling rods.

Drill Bits

The drill bits are used for making holes of the right size on aluminum boats, which normally come with very thin walls. You will also need to make two holes of the same size as the trolling motor shaft (1/4 inch or 0.6cm) so it can be inserted through a sealed ball bearing to prevent any type of leakage from getting inside your boat.

The first hole should be placed near each side of the base, about 3 inches (7.6cm) away from its center, and should have a depth that is enough for you to place a stripped nut inside it before tightening down the bolts that secure your trolling motor to your boat. Make sure that the bolts are tight because they hold everything together and if they come loose it can cause serious damage to your aluminum boat and even injury if the motor is turned on during this process.

The second hole should be placed in a way that it will balance out with the first one, making sure that they are both facing opposite directions from each other. This hole is used for connecting electrical cables to your trolling motor (negative and positive) so make sure you do not drill too close to the bottom of your base because it can cut off some of the cables when inserting them through the holes.

Bolts or Screws

This is basically what holds your trolling motor base in place. You will need to purchase bolts that are at least 4 inches (10.2cm) long and the diameter should be about 1/4 inch (0.6cm).

Make sure that there are no visible cracks or signs of rust on each bolt because it might cause serious damage when tightening down, or even when it’s just mounted into place.

Retaining Nuts

They are used to hold the bolts in place once everything is tightened down. These nuts will prevent your trolling motor from being removed from your boat by a thief because they cannot be accessed when mounted properly.

Make sure that you purchase these types of nuts in a large quantity so you can replace them when needed.

Metal Washers

These are basically flat pieces of metal that have a hole in the center. They come in every shape and size so make sure you get these from your local hardware store or marine supply store.

They are used for protecting areas on the trolling motor shaft against being worn out by bolts, screws, and other tools, so they must always be placed between the item you are tightening (the bolt screw) to your trolling motor base.

Rubber Washers

These are basically flat pieces of rubber that have a hole in the center. They come in every shape and size so make sure you get these from your local hardware store or marine supply store.

Look for the same kind of washers as metal ones, but instead made out of rubber so they can create an airtight seal between your boat’s wall and the trolling motor base.

Wrench or Screwdriver

You will need either one of these to tighten down each nut and bolt. A wrench is better since it creates more torque than a screwdriver but if you do not have access to this type of tool, make sure you purchase different sizes of screwdrivers (also known as ‘hex key’) so they can fit into the recessed areas on each nuts or bolts.

How to Mount Your Trolling Motor

First, you need to make sure that you have all of the parts needed for this job. If you purchase everything beforehand, make sure it is not rusted or has any visible signs of damage.

Locate your trolling motor mount (the base) and find two holes near each side of it; one with a stripped nut inside and another without. Use either a drill or screwdriver to puncture through the aluminum boat’s wall until you can place your metal washer inside them (on top of the hole).

After this is done, use an electric drill or wrench to tighten down each bolt until it will not go any further. This should NOT affect taking off by hand later on in the future, even if loose when initially mounted in place.

Attach electrical cables to trolling motor (negative and positive) and insert into opposite holes that were previously drilled earlier so they will be facing opposite directions from each other. Using a wrench or screwdriver, tighten both nuts onto bolts to secure connections together tightly.

Note: How far you mount your trolling motor away from where the power source is has nothing to do with how much power is given out by your boat’s engines; it is all about personal preference and comfortability. How much power your boat’s outboard motor gives out will determine how far you can router your trolling motor, not the location of mounting it on your boat itself.

Be sure that you used your washers and rubber washers for your trolling motor base and tighten down your retracting nuts onto metal washers to prevent from losing any parts when in use.

Please make sure that you do not forget the rubber washer between the trolling motor base and your boat’s wall because it is important for creating an airtight seal to keep water from leaking through the battery compartment, where all of your wirings will be stored.

To ensure a proper connection with each connection made, check electrical cables by touching a screwdriver on one end and touching another object (such as a pole or any part of the aluminum boat) on the other end. Do this until you have found which cable is positive (+) and which is negative (-).

Final Thoughts on How to Mount Trolling Motor on Aluminum Boat

Remember that different boats require different types of trolling motors due to the amount of power they provide. How far you can run your trolling motor without draining out your boat’s battery depends on how much power it gives out, not the location of mounting it on your aluminum boat itself.

Trolling motors mounts (the base) come in two basic styles: side and transom. How each is mounted varies from one another but how you connect them together will not change; the same goes for plugs and wires.

Always make sure you use washers for each bolt and attach cables into opposite sides as necessary to prevent any future issues with electrical connections later down the road or when operating motors in rough waters/conditions such as heavy seas.

Brett Freese

I've always had a passion for fishing ever since I was young. I started fishing with my grandpa at 6, and he taught me everything I needed to know! I love sharing my knowledge with the community, as well as learning from other anglers. We only get better if we help each other!