If you’re new to boating, understanding outboard engines and what they do can be a bit difficult. With so many types, parts, and components you must know, it can be hard to keep up. The good news is outboard engines aren’t as complicated as they appear to be. All you need to do is figure out the basics and build your knowledge from there.

In this guide, we’ve compiled essential information about outboard engines. You’ll learn almost everything from engine types and brands to maintenance tips and finance options.

The basics: What are outboard motors?

Outboard motors are what propel watercraft vessels. This propulsion system is one of the most used motors for powering boats. It’s installed outside of the boat which frees up a lot of space in the interior of the boat.

Outboard motors offer benefits such as a higher horsepower-to-weight ratio, extended maintenance intervals, and many more. There are different kinds of outboard engines. Figuring out which is right for your boat depends on various factors like use and performance.

It’s vital that the outboard engine you choose fits your boating needs. It must have the right specifications and features so you can make the most out of your boating experience.

Types of outboard engines

The two most popular types of outboard engines are the two-stroke and the four-stroke.

  • Two-stroke outboard engine

These engines are simpler compared to four-stroke outboard engines. Their pistons can complete a combustion cycle in two movements. They burn oil more effectively and there is no risk of losing 30% of the oil. The two-stroke outboard engine also doesn’t need to have a valve train.

The two-stroke outboard engine responds quickly when you throttle. Because of its speed, it’s great for water skiing and riding around the water. It’s also lightweight and considered to have low emissions.

  • Four-stroke outboard motor

This type of engine takes four movements to complete a combustion cycle. It has an oil filter and a self-contained oil cavity in the engine. With a four-stroke outboard motor, you must change the oil after a year or a hundred hours of use, whichever comes first.

A four-stroke outboard motor is great for cruising or spending long hours on the water. The engine can handle continuous stress due to its progressive power and torque. This boat motor is great for fishing trips as the cruise will be a smooth experience.

When deciding between a two-stroke versus four-stroke outboard motor, consider your needs and what you want out of your boat. Your boat’s performance is heavily reliant upon the kind of outboard motor you choose so think about it carefully.

Top outboard engine brands

There are several outboard motor brands for you to choose from. Each brand provides a selection of outboard motors with various features and technology.

  • Evinrude Outboard Motors – This company offers various two-stroke outboard engines ranging in power and torque. Evinrude prioritises performance and maximising fuel economy to provide boaters with the smoothest and most efficient ride. The outboard motors from Evinrude provide optimal throttle response, advanced cooling systems, and great reliability. Outboard motors from this company also have a three-year limited warranty.
  • Yamaha – One of the most well-known brands in the world, Yamaha offers boaters reliable two-stroke and four-stroke motors with great performance and power. The outboard motors from Yamaha are designed to optimise efficiency and reliability while maximising power. The innovative features of this company provide an unparalleled boating experience.
  • Suzuki – Suzuki outboard motors provide a limited range of engines. It has various four-stroke motors varying in power and purpose. These outboard motors are designed with innovative features and advanced systems to create a smooth and precise driving experience.
  • Mercury Marine – Mercury Marine has a huge selection of outboard motors varying in horsepower, from 170 to 600. You can choose high-performance engines, or something better suited for leisurely rides. The company boasts a modern and innovative design with exclusive features to provide great functionality and fuel efficiency. Mercury Marine offers five-year factory-backed coverage.

Finding the right outboard engine for your boat

Choosing the best outboard motor for your boat can be overwhelming. There are various outboard engines available varying in horsepower, and features, and from different brands. Here are some things you should keep in mind while shopping around.

Boat size to power ratio

The size of your boat affects the type of outboard you’ll need. The bigger and heavier the boat, the more power it needs to be propelled.

Dinghies and other light boats typically require a one-cylinder outboard. It can be powered by an outboard with two to three HP. Boats that can carry around a hundred kilograms or at least six metres big would need around four to six HP single-cylinder engines.

Fishing boats and sailboats made of fibreglass or aluminium or those over four metres will need an outboard with two cylinders. Due to their size and weight, they’d need outboards with eight to 20 HP.

Bigger boats that can carry eight people or more will need a lot of power. Outboard engines with four to six cylinders that can reach up to 75 to 90 HP are ideal for these types of boats.

How many engines should your boat have?

More does not always equal fast when it comes to outboard engines. Usually, one high-performance outboard engine is enough to power a boat at high speeds. It’s all about looking at the specifications of the outboard engine and seeing if its features align with your needs.

If you’re thinking of getting two or more outboard motors for your boat, consider the pros and cons first. Also, check if your boat can handle more than one outboard engine. Sometimes, the extra weight of another motor makes the boat more difficult to propel making it slower and using up more fuel.

In some cases, two or more outboard engines can enhance the speed of your boat. Having multiple motors also means you’ll have a spare ready in case an engine breaks down. On the flip side, more outboard engines could mean higher maintenance and fuel costs.

If you do choose a dual outboard motor setup, make sure connections for both engines are separate. Both engines should have access to their own power and fuel sources in case one of them stops working. This modification can be costly, but it’s a good precaution.

Tips for maintaining outboard engines

The best way to keep your boat at peak performance is by maintaining your outboard motor. Keep these in mind when taking care of your outboard engine:

  • Do regular maintenance checks. The more you maintain your boat, the easier it will be every time you do it. This is the best way to avoid an overheated engine, corrosion and leaks.
  • Check the hoses and fittings. Prevent clogging by periodically looking at the hoses and fittings to see if they need replacement.
  • Inspect the propeller. A four-blade stainless steel propeller is a good choice for many boaters. Make sure the propeller doesn’t over-rev to avoid damage to your engine.
  • Keep your fuel topped and use the fuel stabiliser. This will help avoid condensation and the damage it may cause to your engine.

Best boat financing options

If the price of outboard engines is holding you back from having nautical adventures, call Aussie Boat Loans. We can help you find the best outboard loan that meets your needs perfectly. Call now on 1300 889 669 or apply online!


What is the difference between a two-stroke and a four-stroke outboard engine?

The difference between a two-stroke and a four-stroke outboard engine is the number of revolutions it takes to complete a stroke. Two-stroke engines typically require more fuel to operate but have a high weight-to-power ratio. Meanwhile, four-stroke engines can yield high levels of torque at a lower RPM but may be less powerful than their two-stroke counterpart.

Which type of outboard engine is better for water skiing?

A two-stroke outboard engine is great for water skiing because it can reach high speeds quickly.

What are the top brands known for producing high-quality outboard engines?

The top brands for outboard engines are Evinrude Outboard Motors, Yamaha, Suzuki, and Mercury Marine. These companies provide a wide range of outboard motors to match your needs.

How do I determine the appropriate engine power for my boat?

Use your boat’s weight to help you figure out what type of horsepower your ideal outboard engine should have. The heavier the boat, the more horsepower it requires. Look at the different features and specifications of the engine to determine which one suits your needs best.

Is it worth investing in two outboard engines for my boat?

It depends on what type of boat you have and what you use your boat for. Some boaters may benefit from having two outboard engines to achieve the speed they want. Meanwhile, others may find that having more than one outboard engine weighs down their boat and adds to their fuel costs.

How often should I inspect and replace the propeller?

Check your propeller at regular intervals. Propellers typically need replacing only if they’re damaged to the point where they can’t be repaired. Other damage you should look out for are signs of corrosion or if the propeller has been barnacled.

What are some common maintenance tips to keep my outboard engine in top condition?

Regularly check the hoses and fittings, inspect the propeller, keep your fuel topped, and use the fuel stabiliser. Doing these common maintenance tasks will help you avoid inadvertently damaging your outboard engine.