What’s The Difference Between An Inboard And Outboard Motor?

If you are just thinking about getting into boat fishing, or have been fishing with your friends and family on their boats, there is always one major question when it comes to purchasing a new boat, and that is what is the difference between inboard and an outboard motor.

After you make the decision that you really want to buy a boat, you may start to notice how many people in your town or city actually have one, and how many different types and styles of boats there really are, which can make choosing one even scarier, or nerve-racking than before. BUT! Don’t let all the different models, colors, and styles start to overwhelm you at all, because by the end of this article, you are going to understand a bit more about boats and motors than when you first started, so you can narrow down your choice much easier than before.

What Is An Inboard And Outboard Motor?

The term Inboard and Outboard motors come from where the actual motor sits, and is mounted on a boat. An outboard motor sits on the very back of the boat and is mounted on the outside, and has the propeller and rudder exposed to the boat owner.

As for an Inboard motor, there are two types of them and they are mounted on the inside of the boat with the propeller and rudder are built into the boat and are usually underneath the boat, so it will not be exposed to the boat owner when in water. The two different types of inboard motors are called V-Drive and D-Drive and will be explained in detail below.

The third type of motor is an Inboard/Outboard (I/O) engine, or STERN DRIVE, which is slightly different in that the motor is still an inboard being inside the boat, but the drive is attached straight to the motor and doesn’t really have a driveshaft on it at all, so it is more compact, and almost a hybrid of the inboard and outboard motors.

Engine Details

  • Inboard: These engines come in two different types, a Direct-Drive, and a V-Drive style, and will have a longer driveshaft. A Direct-Drive will have the motor mounted in the center of the boat, with a long drive shaft attached to the transmission. These engines are meant for skiing and provide a smaller wake. V-Drive engines are mounted near the rear of the boat with a v-like a driveshaft from the transmission and are primarily used for water sports like wakeboarding and wake surfing because it puts off a much larger wake.
  • Outboard: Outboard motors are mounted on the outside of the boat at the end, and have a self-contained engine and housing. These engines are the most popular for fishing because they are much easier to steer when moving slow, and are also easy to work on while still in the water. The only drawback is that these engines are not nearly as fast as I/O and Inboard motors, so if you need speed for big bodies of water or the ocean, you will need two motors.
motor boat
  • Inboard/Outboard (I/O) Engine: The I/O (inboard/outboard) motor is becoming more popular for boat owners because it is almost a hybrid motor giving you the inboard motor power with the steering of an outboard motor. These “stern drive” motors have more horsepower and the propeller is mounted right onto the engine instead of having a drive shaft that turns. This also makes the boats easier to the trailer when coming off the water, and much more maneuverable in shallow water. Having this capability lets you have the power to tow a skier while still having plenty of room to fish off of and will let you get into tighter places than an inboard motor.

Most Popular Inboard and Outboard Motors

When it comes to motors for boats, here are a few of the most popular motors to look out for, so if you end up buying a used boat from someone other than a dealer, you know what to keep your eye out for and what might be a less popular brand that may be harder to work on and find parts.


  • Volvo Penta V8
  • General Motors
  • MerCruiser
  • Sierra
  • FORD 5.0


  • Honda BF
  • Yamaha
  • Suzuki DF
  • Evinrude E-Tec

Picking one of these motors is going to help you in the long run if you want to do your own maintenance because you will have better luck finding parts fast, so you don’t have to wait on shipping and special orders.

Most Popular Fishing Boat Motor

The most popular motor for fishing is an outboard motor. The reason for this is because the other two motors are generally meant for ski boats and create a bigger wake off the back of the boat. Outboard motors are also easier to steer when you are going slower, so when you are trolling, this is going to give you a lot better handling and maneuverability in the water.

The last reason they are more popular is that you can work on them in, or out of the water, so it’s going to give you a leg up if for some reason it doesn’t start when you are out on the water. The outboard motor can be tilted up so you can work on it, or remove anything that might be tangled from the propeller, which is something you cannot do with an I/O or Inboard motor, those motors must be out of the water to work on them.

Most boats that have an inboard or I/O motor in them, are a bit bigger than most fishing boats, so you may also have a harder time using a small battery-operated trolling motor.


All boats require maintenance, so no matter what engine you decide to go with, you will always need to do tune-ups and oil changes to keep the life of your boat and motor lasting as long it can. Outboard motors are much easier to work on because all you have to do is take the top cover off the motor, and everything is self-contained in one spot.

bearded mechanic checking up the boat

For an inboard motor, you are going to have to get in the boat, and take the cover off, and will have to work on it inside your boat, in a very tight cramped area. Even though this is not impossible, it is going to make it harder to work on, and you have to be very careful not to get your boat carpet and seats dirty and covered in grease and oil, or it could cost you a lot in cleaning fees.

Even though most inboard motors are Chevy, Ford, and Volvo engines which might make parts cheaper for you to get, an outboard motor won’t need as many spark plugs and as much oil as the bigger motors. One thing to keep in mind is that if you are buying a fishing boat for the ocean, you may have two outboard motors attached to the boat to give it that horsepower that is normally lacking in an outboard. Overall, outboards are the cheapest to work on, then I/O motors, and then Inboard motors.


Buying a boat can be confusing, stressful, and downright nerve-racking, but it really doesn’t have to be. Knowing which motor to ultimately go with will save you a lot of time sitting in front of a salesperson, or getting taken advantage from someone on Craigslist or Facebook.

If you are going to fish, and do not need a ton of extra raw horsepower, I would stick with one of the popular outboard motors and you will be just fine. You will have a much easier time working on it, or taking it off the boat if needed to be repaired, and if something should happen on the lake, you can always tilt the whole engine up and find issues much faster.

If you are buying a boat for both skiing and fishing, you may want to look into an I/O motor because it will be easier to handle going slow, and it’s going to be self-contained and not have that long drive shaft in direct drive, or V-Drive motor. Picking a motor is going to be all about your, and your family’s needs when it comes time to hit the lake.

Almost all bass and fishing boats will come with an outboard motor, and amount for a trolling motor, but that doesn’t mean you cannot fish off a ski boat, just make sure you are more careful when it comes to casting. Stick with a popular motor and half of your headaches will be removed just on maintenance costs alone.

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