The Difference Between 2 Stroke and 4 Stroke Engines

One big question that still remains in the motorcycle community is, “What is the difference between 2 stroke and 4 stroke engines?” This is a question that is relatively complex to answer, as they are almost completely different from one another.

If you’re in the market for a new motorcycle or are thinking of purchasing an old one that has a 2 stroke engine, it is always a good idea to understand what you’re getting involved with and how it might be different than a modern 4 stroke engine.


How Engines Work

Engines work relatively the same way, even if they are a 2 stroke or 4 stroke. There are a few differences between each, but those are gigantic differences. To start out, a stroke means the movement of the piston within the engine.

A 2 stroke engine means that there is one stroke in each direction, where there will be compression stroke which causes the explosion of the compressed fuel, and then a return stroke in which new fuel is added into the cylinder that houses the piston.

For a 4 stroke engine, there is often times a distributor that creates a spark to the cylinder when it is near the Top Dead Center (TDC) on the fuel compression stroke. In other words, there is one spark for every two turns of the crankshaft.

Some 4 stroke engines have removed a distributor all together and have made it so that there is a spark for every crank of the piston.

The bad thing about this advancement is that the spark will refire with burnt gasses in the cylinder, which causes the spark plug to wear out slightly faster as opposed to the length of time it would normally wear out with new fuel injected.

Why Does The Debate Between 2 Stroke and 4 Stroke Matter

Well, there are several reasons as to why the debate between 2 stroke and 4 stroke engines matter. There are various positives and negatives about both types of engines, and everyone has their preference depending on which one they have ridden more.


Some of the complaints about a 2 stroke engine are that they feel like cheaply made engines that have oil mixed into the fuel which causes problems. In addition, individuals complain about how there are some primitive technologies that don’t control the proper fuel and air mixture required for proper firing.


And then most often the debate between the two is about power, simplicity, and cost to work on. 2 stroke engines are easier to work on, have a cheaper overall cost, and offer more power than a 4 stroke engine. Whereas in contrast, 4 stroke engines have had a lot of developmental costs, less power available, are more difficult to work on, and offer a more refined fuel to air mixture.

The Exact Differences

Now that we have broken down why this is important, we’re going to explain some of the key differences between a 2 stroke and a 4 stroke engine.

2 Stroke Engines

4 Stroke Engines

  • One Stroke For Each Revolution
  • Lighter Flywheel
  • Engine Is Lighter
  •  Engine Design Is Simpler
  • Less Expensive
  • More Mechanical Efficiency Due To Less Complex Engineering
  • Less Output Per Engine Size
  • Hotter Engine
  • Engine Is Air-Cooled
  • Larger Fuel Consumption
  • Less Thermal Engine Efficiency
  • Consumes More Lubrication Oil
  • Extensive Wear And Tear On Parts 
  • Smaller Engine Size
  • Louder Engine Noise
  • One Stroke For Two Revolutions
  • Heavier Flywheel
  • Engine Is Heavier
  • Engine Design Is More Complex
  • More Expensive
  • Less Mechanical Efficiency Due To More Complex Engineering
  • More Output Per Engine Size
  • Cooler Engine
  • Engine Is Liquid-Cooled
  • Smaller Fuel Consumption
  • Greater Thermal Engine Efficiency
  • Consumes Little Lubrication Oil
  • Less Wear And Tear On Parts
  • Larger Engine Size
  • Minimal Engine Noise

As you can see when we go through the exact differences between the engines, there are some glaring differences. So now we have to answer, which one is ultimately better than the other, knowing what separates the two.

Which Is Better: 4 Stroke or 2 Stroke

Knowing which is ultimately better will help make you a more informed individual with purchasing power. Things you have to consider are how much time you will be able to work on an engine if something were to go wrong, what budget you are looking at, and what your usage pattern is going to be.

The 4 stroke is ultimately the better option between the two. While the two-stroke does have its benefits like cheaper mechanic costs, less weight, and quicker acceleration, there is a reason that almost every company has switched to 4 strokes for their engines. 4 strokes have years of technology research and advancements that make it a more efficient expensive engine that riders have come to love.

Bradley Miller

There is nothing that compares to the feeling of controlling a thundering beast beneath you. In addition to the joy of the ride a motorcycle has many advantages over any other vehicle. You learn how to drive the smarter way with traffic rules on the road; also you are always in the state of complete-awareness when on the ride.