What Size Motor for a Jon Boat?
Because jon boats are flat bottom fishing boats ideal for fishing in rivers, lakes and shallow waters, they typically don’t require the powerful engines you’ll see on sport fishing boats or even smaller bowriders and standard fishing boats. But the size of the motor you need is definitely relative to the size of your jon boat. Let’s take a look at some of the most popular and helpful options.
Trolling Motors vs Outboard Motors
A jon boat can use either a trolling motor, which can be either a hand control trolling motor or a foot control trolling motor, or a standard outboard motor. Because jon boats are smaller, lightweight boats they can use a trolling motor as their primary source of propulsion and still be very useful. Larger boats may benefit from having a more powerful outboard and it’s not unheard of for some anglers to choose both so they have a powerful outboard to get where they’re going faster and then a trolling motor to navigate around the shallows of their favorite fishing spot. This can come down to personal preference in a lot of cases, but the bigger a boat gets the more power you tend to need to move it so the more likely you are to want to use a smaller outboard in some cases.
I would say a trolling motor alone can handle a jon boat up to 14 feet. At 14 feet you’d be pushing your luck in some cases, however so the pair together is definitely not a bad approach. At 16 feet you definitely want to have an outboard for sure with a trolling motor as an option.
Remember that a jon boat has a flat bottom and a squared of bow rather than a v-shaped hull design that is typical of other boats. These are not only not designed for speed, they can’t handle it very well without modifications. A jon boat with a 400 hp engine on the back would probably flip like a pancake in a heartbeat. You don’t want the most powerful engine possible for a jon boat, you just want the best one for the job.
Runtime will also affect which motor is the best for your boat. A small trolling motor can be more than powerful enough for a jon boat, but you may sacrifice battery life when you choose something smaller and therefore limit your time on the water.
Thrust Needed for a Jon Boat
So how do you know how to pick the right motor? What is ideal for a jon boat? If you’re using a trolling motor, you want one that can provide enough thrust to keep you on the slow and steady. About 5 miles per hour is all you’re looking for at most so as the size of your boat increases, so too will the horsepower needed to provide that. You want to be able to get on plane quickly and easily and you need it to be strong enough to keep you going in a mostly straight line against any wind or current if you have to deal with that.
The ideal amount of thrust for a boat is 2 lbs per every 100 lbs of boat weight. So let’s say you have a 10 foot aluminum jon boat which weighs 100 lbs. You and your gear add another 200 lbs for 300 total. To calculate thrust you’d divide 300 (your total weight) by 100 (the amount of weight requiring 2 lbs of thrust) and then multiply by 2 (the thrust required for every 100 lbs).
300/100 X 2 = 6 lbs of thrust
Keep in mind that more weight will need more thrust so you need to accurately measure your total weight including passengers, gear and fuel as well as the boat itself. And if you’re on water that has a current, or it’s a windy day, the boat will require more thrust to work against those conditions. In our calculation above, 6 lbs of thrust is the bare minimum. I’d say 8 lbs would be ideal in case you’re working against a bit of a breeze at some point or maybe you miscalculated the weight to some degree.
Most motors are sold with both horsepower and thrust listed in the description so you know what to look for.
Gas Trolling Motor vs Electric Trolling Motor
Electric trolling Motors are available in 12V, 24V and 36V options. A 36V trolling motor can offer at least 80 lbs of thrust and you’d need a pretty large and heavy jon boat to require that. Most of these boats will make do with much less. You can get a 12V, 2-hp trolling motor that has 65 lbs of thrust.
The only reason you might want a higher voltage trolling motor on your jon boat is run time. A 24V trolling motor will run off of two batteries and will last significantly longer than a 12V motor. So, as you can see, there are a few considerations when it comes to choosing your motor.
Gas trolling motors are still an option as well and refueling tends to be easier than recharging a battery if you run out of power in a pinch. In terms of size, you’ll need the same thrust from either gas or electric but you will need to calculate weights appropriately. The weight of your electric trolling motor’s battery versus the weight of the fuel in a gas powered trolling motor. An electric motor is, generally speaking, a lot lighter than a gas powered one.
If you’re using a gas powered outboard then the weight of that plus its fuel also needs to be factored in as well.
When it comes to trolling motors the trolling motor shaft length is something you need to consider as well. With pontoon boats you might want a much longer shaft length to prevent the prop from coming out of the water. However, a jon boat, with a low freeboard and small transom, does best with a shorter overall shaft length. Obviously this is adjustable on some trolling motors but make sure that the shaft length is another thing you’re paying attention to when choosing the right size motor.
A longer shaft increases the draft of the jon boat and that’s the exact opposite of why you’re using a jon boat in the first place. It has a shallow draft and you can use it in shallow waters.
The shaft length depends on your transom height. Minn Kota has a recommended shaft length of 42” for any jon boat with transom mounted trolling motors. A shorter transom means a shorter shaft can work, however. A 36” shaft is recommended for a 16” transom, for instance. If you’re not using transom mount trolling motor and instead are looking at a bow mount trolling motor, you need to measure from the bow to the waterline and add 20 inches.
Rough water conditions require a long shaft for transom mount trolling motors or bow mounted as well, so keep that in mind based on where and how you go fishing.
What Size Motor for an 8 Ft Jon Boat? Under 2 HP
These tiny jon boats are little more than dinghies and are probably best used for one person or maybe for taking small kids out on the water in a pond or very small lake. At this size, I wouldn’t even recommend a motor at all to be honest or, if you do need something, a bare bones 2 hp or less should get you where you’re going without much trouble. Keep it small and easy to manage and you should be fine.
What Size Trolling Motor for a 10 Ft Jon Boat? 3 to 5 HP
This is a good starter size for jon boats, especially if you have access to a small lake that you can get to easily. This is still a relatively lightweight and small size so you aren’t going to need a lot of thrust from a trolling motor to get this size boat where you need it to be. At this size a motor with 3 to 5 horsepower should be more than adequate to meet your needs even if the wind picks up and pushes you around a bit.
Most jon boats have a maximum horsepower rating from the manufacturer so that’s always worth consulting but I don’t think I have ever seen a 10 foot jon boat that went above 5 horsepower in its recommendation. It’s just not safe to try anything bigger and honestly the smaller sizes of 3 and 4 would be great.
At this size, you should be able to cruise at up to about 10 miles per hour depending on conditions.
What Size Trolling Motor for a 12 Ft Jon Boat? 5 to 7 HP
A 12 foot aluminum jon boat probably weighs around 110 lbs so we’re still not adding a lot of weight from the boat itself requiring more thrust. But you can comfortably fit 2 or even 3 adults and more gear in a 12 foot jon boat so the potential thrust needed would be higher. Additionally, this size of boat is better suited for larger bodies of water and may have to deal with a stronger current. Plus, at a larger size, the wind will affect it more. All of these factors are why the horsepower is increasing again.
This size motor should allow you to reach speeds of about 10 to 15 miles per hour.That said, I’ve seen people go bigger on a 12 foot jon boat and use motors that are up to 10 or 12 horsepower. A lot of this will depend on weight and stabilization to get it to work properly and safely and if you’re not confident I wouldn’t risk pushing it.
What Size Trolling Motor for a 14 Ft Jon Boat? 12 to 15 HP
A 14 foot jon boat is a respectable size and has some bulk to it. You’ll notice the horsepower recommendation has bumped up quite a bit over the 12 foot version and that’s in part because even though we’ll only be two feet longer now, the weight has increased quite a bit as well. A 14 foot jon boat likely weighs around 160 lbs to 170 lbs. It can carry up to about 650 lbs to 700 lbs as well so you can see why a power boost may be necessary.
With as many as 4 passengers on a boat like this, you’ll need perhaps 16 pounds of thrust but you’ll also be fighting against potential current and wind so more thrust is never a bad thing at this size. I have seen some 14 foot jon boats also using 20+ horsepower to get around
What Size Motor for a 16 Ft Jon Boat? 20 to 35 HP
At 16 feet, this is about where I’d start seriously considering shaking things up between a trolling motor and an outboard motor. As you can see from the recommendation, we have a large range here of 20 horsepower to 35 horsepower. That’s 15 horsepower difference, which is as much as we recommended for a boat just two feet shorter.
Because of the size of this boat and the potential amount of gear, passengers and places you can use it ranging from the calmest of lakes to rivers with strong currents, the power of the engine can vary greatly.
A 16 foot jon boat can carry nearly 1,000 pounds of additional weight plus the hull itself is going to weigh 360 lbs. That means you need close to 28 pounds of thrust for the fully loaded boat weight of a 16 footer.
If you plan to do fishing in a river or a larger lake, you may find the higher horsepower definitely more efficient. This is where an outboard over a trolling motor comes into play as the extra power can get you moving faster and also keep you on the straight and narrow when you’re fighting wind and currents. A combination of both a trolling motor and outboard could work as well, but may not necessarily be something you need at this length, either.
Though you don’t necessarily need both a trolling motor and an outboard, I would say you need the outboard alone if you’re going with a single engine. This is just too much boat to control well with only a trolling motor in most conditions. On a still pond or lake then maybe a trolling motor could do it? But it seems weird to use a boat this large on a calm little pond or lake anyway, plus you never know when the wind could kick up and just stress a trolling motor on its own out.
What Size Motor for an 18 Ft Jon Boat? 40 to 60 HP
The hull of an 18 foot jon boat is going to be around 600 lbs on average. This is where weights can really start getting a lot of variety, mind you. Some weigh under 500 lbs and some will be over 800 lbs depending on how they are manufactured. The Smoker Craft Freedom 180 has a dry weight of just over 1,000 pounds so it’s a real mixed bag here.
The weight capacity of a jon boat of this size also has a great range. You can carry anywhere from 1,300 lbs up to over 1,800 lbs in that Smoker Craft. At that size you need a motor with a minimum of 57 lbs of thrust. Given the size and potential conditions, you’d definitely want something more reliable and powerful, however. Plus, at this size, a jon boat can certainly handle more than the bare minimum without risking your safety.
This size boat should easily be able to manage 30 to 35 miles per hour on the water without causing any problems. A larger engine can get more speed but you’ll find it a rocky ride and it will be difficult to stay on plane. By the same token you’re probabl;y not using a boat this large just to troll around in the weeds next to the shore on a little pond, so more power is necessary.
An 18 foot jon boat can do really well with a 60 hp outboard and a 12V or even 24V trolling motor to handle the fine maneuvering in the shallows when you go fishing.
What Size Motor for a 20 Ft Jon Boat? 70 to 100 HP
A 20 foot jon boat is probably about as big as any jon boat owner would ever use, though you can certainly find larger ones out there. At this size the horsepower really needs to be kicked up. 70 horsepower would be a minimum but 100 and even 120 horsepower are not outlandish. I’ve seen at least one 20 foot jon boat with a 150hp outboard that ran really well.
At this size, manufacturers make a lof of changes to the design so variations in weight distributions and features can greatly alter the hull weight. You can find a 20 foot jon boat that weighs around 700 lbs like the Lowe Roughneck 2070 and ones that weigh over 1,900 pounds like the Tracker Grizzly 2072 CC Sportsman, though that one is a 21 footer. Point is, the weight difference is all over the map so you need to pay more attention to the specific model than just the overall length, especially at this size. That boat needs as much as 75 pounds of thrust to get it going so you need a much more powerful motor.
If you’re fishing in a 20 foot jon boat, or any larger versions, I would definitely recommend both the outboard and an additional trolling motor. The best way to determine the appropriate engine is to check with the manufacturer, however. It’s very risky to talk in generalities when you get to boats this big since there are so many variables to consider. It’s very easy to either underpower or overpower a boat at this point, both of which can leave you with a bad experience.
The Bottom Line
The size of your jon boat’s motor will be affected by a handful of factors. You need to be most concerned with:
- Boat length
- Boat weight
- Conditions in which the boat is being used.
A longer, heavier boat used in windy conditions or a river with a current will require a more powerful motor. You’ll need about 2 lbs of thrust per every 100 lbs of boat weight which can be calculated fairly easily. In general, a jon boat is not built for speed so a powerful engine is not a necessity, rather just a motor that can move you where you need to go at a reasonable speed.
Categories: Jon Boats