What are the Different Types of Outboards? [Explained]


Outboard motors can be classified according to a variety of aspects, of which the most common are as follows:

  • Size: Portable, Midrange, High-performance
  • Fuel: Gas, Diesel, Propane, Electric
  • Shaft length: Short, Long, Extra-Long, Extra-Extra Long
  • Propulsion: Propeller, Jet-drive

If you want to find out more about the different classes, this post is for you.

We at PowerSportsGuide have compiled all you need to know under one roof!

Outboard Motor Classification I: Engine Power

What sizes do outboard motors come in? We get this question more often than not.

As a rule of thumb, the most popular outboard motors are available with 1.5-600+ HP engines, which can be classified into the following categories:

  • Portable: 1.5 – 20/25 HP
  • Midrange: 25/30 – 100/115 HP
  • High-Performance: 115/130 –650 HP

Let’s get down to the nitty-gritty and talk about each in detail!

Portable Outboards

As the name suggests, portable outboard motors are designed for easy transport. These motors can be attached to a boat with a set of clamps that ensure a quick installation.

This type of outboard is usually designed with tiller steering and a manual starting system.

They are commonly used on small dinghies, tenders, and Jon boats. However, they can be also used as trolling motors on larger boats or auxiliary motors on sailboats.

The key features of portable outboard motors are as follows:

  • HP: 1.5-20/25 HP
  • Weight: 29-150 lbs.
  • Displacement: 50-432cc
  • Cylinders: 1 or Inline-2
  • Fuel system: Carburetor or EFI

Midrange Outboards

Engine power of midrange outboards starts at 25 or 30 HP depending on the manufacturer.

These motors are great for smaller pontoon boats, and inshore fishing boats, but the largest models are also used on small offshore boats.

The key features of midrange outboard motors are as follows:

  • HP: 25/30-100 HP
  • Weight: 130-400 lbs.
  • Displacement: 550-2100cc
  • Cylinders: Inline-3 or Inline-4
  • Fuel system: EFI (or carburetor on certain older models)

High-Performance Outboards

Outboards with an engine power of 100 HP and above are considered high-performance or large outboards.

These motors are typically used on performance boats, larger pontoons, and heavier offshore boats.

They can be rigged in a single, twin, triple, or quad configuration depending on the design and the power demand of the boat.

The key features of large outboard motors are as follows:

  • HP: 100-600+ HP
  • Weight: 350-1260 lbs.
  • Displacement: 1800-7600cc
  • Cylinders: Inline-4, V6, V8, V10, V12
  • Fuel system: EFI (or carburetor on certain older models)

Outboard Motor Classification II: Fuel

What kind of fuel do outboard motors use? Simply put, the most common outboard fuel types are as follows:

  • Gasoline
  • Diesel
  • Propane
  • Electricity

Let’s talk about the pros and cons of each in a nutshell!

Gasoline Outboards

Gasoline-powered outboard motors are by far the most popular models in the marketplace. They have a long history since the first models were developed in the early 1900s.

They offer a great power-to-weight ratio, smooth operation, and durability.

In the past carbureted 2-stroke gasoline motors dominated the market, but since the mid-2000s their 4-stroke brothers have become more prevalent.

Over the years EPA restrictions have become more and more strict, which further shrunk the market for 2-stroke outboards.

As a result of this, major manufacturers now only offer outboards with 4-stroke engines.

The last major 2-stroke outboard brand was Evinrude, which disappeared from the marketplace in 2020.

Diesel Outboards

Besides gas-powered models, diesel outboards are also becoming more and more popular. They are marketed by many well-known manufacturers including Mercury, OXE, and Cox.

Although diesel outboards tend to be more expensive than their gas-powered counterparts, they are more fuel efficient and require less maintenance.

Therefore, they can be more economical especially if the boat is used a lot.

What’s more, diesel is less flammable than gasoline, which makes these motors safer.

Propane Outboards

Compared to gas and diesel motors, propane outboards are relatively new in the marketplace.

These motors are powered by propane gas, which ensures a cleaner operation and lower running costs.

Also, these motors run stronger, offer a wide range of power, and are easier to maintain than standard gas/diesel motors.

On top of that, these motors are much easier to start since propane is stored in a pressurized form.

Unfortunately, only portable outboards up to 25 HP are available with propane engines.

Electric Outboards

Besides motors with internal combustion engines, electric outboards are also gaining in popularity.

These clean silent motors are primarily used as trolling motors, or as the main power source on tenders, dinghies, canoes, and fishing kayaks.

Most electric outboard motors produce 1-50 HP, but you can also find a few high-performance 100-200 HP models in the marketplace.

Outboard Motor Classification III: Shaft Length

We can also classify outboard motors by their shaft length, which determines what size boat the outboard motor can be installed on.

This is because the motor must match the transom of the boat; the higher the transom the longer the propeller shaft is required to be.

The standard shaft lengths of outboard motors are as follows:

  • Short shaft (S): 15 inches
  • Long shaft (L): 20 inches
  • Extra-long shaft (X): 25 inches
  • Extra-extra-long shaft (XX): 30 inches

Since smaller motors are designed for smaller boats, these models typically come with shorter shafts.

Outboard Motor Classification IV: Propulsion

Last but not least, we can also classify outboard motors by their propulsion system. The most common categories are as follows:

  • Propeller
  • Jet drive

Propeller

It’s safe to say that most outboard motors are marketed with standard propeller propulsion.

This design offers the simplest operation and the highest efficiency available. You can also vary the size of the prop, which can change the performance of the boat. (You can increase acceleration or top speed based on your needs.)

On the other hand, the prop can be dangerous or get damaged by rocks and debris.

Jet Propulsion

Jet outboards are similar to their prop-powered counterparts except for the jet propulsion system.

The latter works basically in the same way as the propulsion system on jet boats, although somewhat smaller in size.

They do a good job in shallow and rocky water where the chances of propeller damage is high. This is why jet outboards are commonly used in many rivers, especially in Alaska and the Northwest.

Keeping durability and safety in mind, they are often paired with an aluminum hull.

Besides their advantages, jet outboards have some cons as well, which are as follows:

  • Less power
  • Higher fuel consumption
  • Different handling
  • Difficult rough water maneuvering
  • Lack of reverse
  • Noisy operation
  • Prone to getting clogged with debris or grass

Takeaways – What are the Different Types of Outboards?

Outboard motors can be classified according to a variety of aspects, of which the most common are:

  • Size: Portable, Midrange, High-performance
  • Fuel: Gas, Diesel, Propane, Electric
  • Shaft length: Short, Long, Extra-Long, Extra-Extra Long
  • Propulsion: Propeller, Jet-drive

References:

mercurymarine.com, yamahaoutboards.com, www.suzukimarine.com, marine.honda.com

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