2-Stroke vs. 4-Stroke Outboard Motor: A Guide for 2020

Apr 2, 2020 ·

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If you’re a boating enthusiast, you’ve probably wondered what the differences between 2-stroke and 4-stroke outboard motors are. At first glance, many people assume that 4-stroke motors are more powerful and 2-stroke motors are designed for those looking for speed. However, this isn’t always the case.

Both 2- and 4-stroke outboard motors have their pros and cons depending on what you’re looking for. In fact, today’s technology has led to great advancements in both types of motors, making their differences less significant. It all comes down to your preferences and which motor is right for your boat!

Whether you’re purchasing a motor or training for a career as a marine technician, it’s important to know how each type of engine works. Keep reading to learn all about the unique characteristics of 2- and 4-stroke motors, including reliability, top speed, weight comparison and fuel economy. 

2 Stroke vs 4 Stroke: Common Misconceptions

It’s no secret that technology has greatly transformed the marine industry. Much of what we once knew about 2- and 4-stroke motors has changed in recent years, so it’s important to stay up to date on the latest models and what they have to offer.

In years past, 4-stroke motors were not as sporty and performance-oriented as 2-strokes. In comparison to 4strokes, 2-stroke motors were lighter, had quicker acceleration and were smaller and more portable. For these reasons, 2-strokes dominated the market for many years.

Despite this, a common concern with 2-stroke motors was the fact that they would use more fuel to operate. Therefore, people would choose 4 strokes because of their fuel efficiency and lower emissions. 4-strokes also tended to run smoother and quieter in comparison to 2-strokes.

In the last 15 to 20 years, however, both 2- and 4-stroke motors have made significant improvements. Each engine has stepped up its game to match the other in quality, emissions and performance. Today, both products are comparable and have gained on the other’s technical strongpoints.

How 2-Stroke Outboard Motors Have Evolved

A 2-stroke outboard has been known for its fast acceleration, portability, smaller size and lighter weight. However, their downfalls were that they were noisier and had higher emissions.

To combat this, electronic oil mixing is used to create little to no exhaust smoke. Computers have helped to improve fuel economy and emissions while maintaining the 2-stroke’s fast acceleration and high power. Their fuel economy is now comparable to today’s 4-stroke motors. 

How 4-Stroke Outboard Motors Have Evolved

A 4-stroke outboard has been known for its power, low emissions, fuel mileage, lower sound level and how smooth they run. Their downfalls were that they were heavier, less portable and slower accelerating.

Thanks to modern technology, today’s 4-stroke motors are comparable to 2-strokes in their size, speed, portability and acceleration. They’re the go-to motor for many and continue to make advancements in their performance. 

Important Differences to Note

While 2- and 4-stroke motors have become more similar in the benefits they offer, the way they work internally differs.

In 2-stroke motors, oil is blended with gasoline. As the fuel goes through the engine, it consumes small amounts of oil for lubrication. Therefore, oil changes are not required to power the engine because the oil is continuously injected. The customer simply maintains an oil reservoir either located in the boat or on the engine.

In 4-stroke motors, there is an oil filter and self-contained oil cavity within the engine, similar to the way it works in a car. An oil change is typically required after 100 hours or one year of use.

2-Stroke vs. 4-Stroke Outboard Reliability

One of the biggest things to look for when choosing an outboard motor is reliability. There’s nothing worse than getting in your boat only to find that it won’t start! It’s important to choose a motor that is dependable, consistent and worry-free.

Fortunately, the 2- and 4-stroke motors in today’s market are very dependable. They’re built to last and power any adventure. When in doubt, do your research online and look at reliability ratings for different motors. It can also help to talk to other people in the boating community who have had personal experience with different types of boat and motor combinations.

2-Stroke vs. 4-Stroke Outboard Weight Comparison

Depending on the size of your boat, weight may be a concern when choosing an outboard motor. Smaller boats are often more weight sensitive, so it’s important to choose a motor accordingly.

2-strokes have typically been preferred by those worried about the weight of their motor as they are lighter. However, this has become less of a concern with 4-strokes, as they are now much lighter than they were in years past.

2-Stroke vs. 4 Stroke Outboard Motor Top Speed

As stated previously, 2-stroke motors used to be the choice among those looking for speed. However, four stroke outboard motors have become much faster and lighter, making today’s market very competitive.

When it comes to speed, the differences between motors doesn’t necessarily have to do with whether they’re a 2- or 4-stroke. Every manufacturer is different, and there are even different variations between products from the same manufacturer. Always do your research and compare.

2-Stroke vs. 4-Stroke Outboard Fuel Economy

In the past, 2-stroke motors burned more fuel than 4-strokes. However, the 2-cycle product is now much more efficient in its injection methods used to bring fuel into the engine.

Some companies claim to be more fuel efficient than others, but in many cases, it’s a matter of splitting hairs. As long as it is a modern-day 2-stroke, it is most likely comparable to 4-strokes when it comes to fuel efficiency.

Choosing Which Motor is Right for You

When deciding between a 2 stroke vs 4 stroke boat motor, it all comes down to your preferences and the type of boat you have. As with any purchase, always do your research online and determine which features are most important to you, whether it’s motor features, weight, fuel efficiency or all of the above. Looking at manufacturer statements and boat tests online can also help guide you in your search.

The environment in which you use your boat is another important factor to consider. For example, when buying car tires, you wouldn’t buy snow tires for driving in Phoenix, where it doesn’t snow. This same concept applies to your boat’s motor, so always make your decision based on how you use it — whether it’s for fishing, performance application or carrying heavy loads.

Finally, selecting a product largely depends on who your local dealer is. Sometimes, this decision is not just about the engine itself, but rather, your ability to get support for the product when it breaks down or needs annual service. For example, you wouldn’t want to buy a Subaru if there wasn’t a Subaru dealer for 100 miles.

Consumers shouldn’t be afraid of any modern-day product — they are all built very well. If you are more comfortable with a particular dealer when it comes to getting service or picking up parts, chances are, you will be able to find a motor from them that works for your boat.

What Does This Mean for Aspiring Marine Technicians?

As an aspiring marine technician, it’s important to know how both 2- and 4-stroke outboard motors work. According to Marine Mechanics Institute (MMI) instructor Larry Hutt, these engines have very long lives, so as a technician, you will most likely have to service and repair older models in addition to today’s modern-day engines.

The technology behind 2- and 4-stroke engines is very different, so having training on each type of product is key. At Marine Mechanics Institute in Orlando, Florida, students work with the fuel systems on both types of engines in order to prepare for careers in the field.1

In addition to this, MMI students enrolled in the 51-week Marine Technician Specialist training program learn everything from basic engine theory to the more technical aspects of marine product service, rebuilding, troubleshooting and repair. Students complete three-week, manufacturer-specific courses designed to provide them with technical and hands-on training specific to the following brands: 

Now is an exciting time to pursue a career in the marine industry. As the field continues to evolve, technicians who understand how to work with the latest tools and technology will be needed to work on today’s modern engines and boats. If you’ve been debating when to start your training, there’s no better time than now. With MMI’s 51-week program, a career in the industry might be closer than you think!2

Wondering what types of careers marine technicians can pursue? Check out our career guide.

Train for a Career as a Marine Technician

MMI’s 51-week Marine Technician Specialist Training program is designed for those looking to pursue a career in the marine industry. From inboard gas and diesel to outboard 2- and 4-stroke motors, your training will cover a wide variety of topics. To learn more, visit our program page and request information today.

With classes starting every 3-6 weeks, no need to wait to start your career.
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1) MMI is an educational institution and cannot guarantee employment or salary.

2) For program outcome information and other disclosures, visit

Universal Technical Institute of Illinois, Inc. is approved by the Division of Private Business and Vocational Schools of the Illinois Board of Higher Education.


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