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2 Stroke Vs 4 Stroke Outboard Motors:
The New and Improved Boater’s Guide

2 stroke vs 4 stroke outboard motors – which are better? This is an age old debate that has spanned throughout the decades. 2 stroke engines were once notorious for being loud, heavy on fumes and somewhat off-putting to other motorists running their smooth 4 strokes. Yet, many 2 stroke owners took pride in their powerful engines that could quickly propel them from one sandbar (or fishing spot) to the next.

However, in modern times – the lines have blurred. The gap between 2 stroke and 4 stroke outboard motors is beginning to close. That being said, there are still differences between the two. It is important to consider the pros and cons to each while taking personal preference and boating style into consideration.

Let’s start by taking a look at how these two motors function.

2 Stroke Vs 4 Stroke Outboard Motor Function

2 Stroke Outboard Motor Function

A two-stroke (or two-cycle) engine is a type of internal combustion engine which completes a power cycle with two strokes (up and down movements) of the piston during only one crankshaft revolution. This is in contrast to a "four-stroke engine", which requires four strokes of the piston to complete a power cycle during two crankshaft revolutions. In a two-stroke engine, the end of the combustion stroke and the beginning of the compression stroke happen simultaneously, with the intake and exhaust (or scavenging) functions occurring at the same time.

So what does this mean and why does it matter?

In a 2 stroke outboard motor, two strokes complete one combustion cycle in two strokes as opposed to four. This is a fairly minimalist cycle that results in a whole lot of power in a short amount of time. Simple, affordable maintenance is another factor that weighs in due this motor’s basic functionality. While 2 stroke outboard motors are typically not maintenance free, maintenance is fairly cheap and easy to fix when issues arise.

4 Stroke Outboard Motor Function

A four-stroke outboard motor is known as an internal combustion engine (or IC) where four separate strokes of the piston turn the crankshaft in order to complete a single cycle. These four phases are known as:
4StrokeEngine Ortho 3D Small

  1. Intake
  2. Compression
  3. Combustion
  4. Exhaust


How does this functionality impact the way a 4 stroke outboard runs? Because there are more steps, moving parts and pieces in order to complete a single combustion cycle, 4 stroke outboards are arguably more complicated than 2 stroke outboards. Thus, they tend to be heavier and more costly to fix. However, 4 stroke outboard functionality is known to be more reliable overall.

2 Stroke Vs 4 Stroke Outboard Comparison

How do 2 stroke and 4 stroke outboard motors measure up when it comes to features? We put together this handy little infographic that helps break it down for you.

2 stroke outboard motors are known to be more affordable than 4 stroke outboard motors. However, the make and model of your outboard will weigh in heavily to the price factor.

4 stroke outboard motors are rich with features and functionality intended to keep them running for longer periods of time. A 2 stroke motor’s combustion cycle is faster, running at higher RPMs. Thus, they typically have a shorter life-cycle. 4 stroke outboard motors typically stand the test of time and offer greater reliability..

A 2 stroke outboard motor has a faster pick-up speed than a 4 stroke. However, once running, both offer speed and power. The make and model of your outboard motor will be the biggest determining factor as to how fast your motor can run.

A 4 stroke outboard motor is much quieter at idle. While running, 4 strokes still tend to be quieter but depending upon the manufacturer, some 2 strokes compare to 4 stroke noise level while running.

4 stroke outboard motors are on average, slightly more fuel efficient. While this can vary upon the manufacturer, 4 stroke outboard motors are designed to get better mileage and release fewer fuel emissions. At the same time, 2 stroke designs are not far behind. 2 stroke manufacturers are closing in on that as well. As a result, the gap is beginning to close.

Due to it’s simplicity, a 2 stroke motor is easier and more affordable to maintain. 4 stroke outboard motors typically require maintenance more frequently which can be costly.

On average, 2 stroke outboard motors are lighter than 4 stroke outboard motors. 2 stroke outboard motors have fewer parts and moving pieces than 4 stroke motors. For this reason, they tend to be lightweight.

Today, there are numerous changes and improvements taking place in outboard motor manufacturing and design. Over time, expect to see lighter weight 4 stroke outboard motors, 2 stroke outboard motors made with even greater fuel economy in mind and improved reliability across the board.

Here are a few important factors to consider.

  • Boating style: Do you like to cruise and enjoy the scenery or do you like a boat that can pickup and go? If you want shorter bursts of power, a 2 stroke will probably be your pick.
  • Affordability: Again, pricing varies greatly depending upon make and model. However, you will likely discover that 2 stroke motors are, on average, more affordable. If you don’t mind a motor that runs louder and tends to use up fuel slightly faster, you may veer towards a 2 stroke outboard motor.
  • Durability: Looking for an outboard motor that will last for many years down the road? 4 stroke outboard motors are well-known for their durability and reliability.
  • Fuel and Environmental Impact: If pollution and fuel emissions are major concerns for you, a 4 stroke outboard motor is your best bet. That being said, 2 stroke outboard motor manufacturers are making improvements in this arena.
  • Noise Level: Are you looking for a motor that idles in silence? Or, do you enjoy a roaring engine? When it comes to noise level, 4 stroke outboard engines tend to be quieter.
  • Maintenance: If you are mechanically inclined, you will probably be able to keep up on 2 stroke motor maintenance yourself. 4 stroke motors typically require the help of a professional – and repairs can be pricey.
  • Engine Weight: Are you looking to fly like a bird gliding over the surface of the water? If so, a 2 stroke motor will probably make you quite happy due to it’s lightweight design.

Well, that’s a wrap! We hope you’ve enjoyed this post and that we’ve provided some useful information as you continue to research the outboard engine type that works best for you and your personal boating style. To summarize, 2 stroke motors and 4 stroke motors each offer their own unique benefits as well as drawbacks.

Now…on to you! Is there anything we’ve missed here? Anything you would like to add that you would consider an important factor for our readers looking to make a decision? We’d love to hear your thoughts.