In the ATV industry, you will find ATVs with either two stroke or four stroke engines. Both run on gas, both send power to the wheels and both can be found in the market. So, what is the difference? What is all this talk about two stroke and four stroke engines? Which is better? All are important questions if you are looking to buy an ATV, and all will be answered in this article.
Most people will say a four stroke engine is better because it is much easier to maintain and overall lower-maintenance. There are definitely ups and downs to both but overall a four stroke will generally last longer and a two stroke is known for its consistent break downs.
The mechanics that go into the different types of engines are very interesting and important to know if you are looking to own an ATV. We will cover them in more detail throughout this article.
A Closer Look at The Engines
The Two Stroke Engine
The two stroke engine is becoming less popular by the day. Four strokes are taking over markets because of their lower maintenance design but does the two stroke deserve this downfall? The reality is two stroke engines have many pros that beat even this coveted four stroke engine. Generally a two stroke will drive faster because of its lighter design and the fact that its engine cycle only takes two strokes to combust. Two strokes are also cheaper because they have less parts.
A two stroke engine obviously works with only two strokes. One stroke is when the piston either moves up or down. To keep it simple in explaining how a two stroke engine works, a mixture of fuel and air is released into the cylinder (where the piston is) and compressed by the piston when it moves up. A small piece called a spark plug then ignites the mixture which is highly combustible because of the gas inside of it. This combustion then shoots the piston down and the burnt fuel mixture is released. That is it, that is the beauty of a two stroke engine, not a lot of parts, lightweight and only two strokes to complete a cycle.
For a closer look at how a two stroke engine works check out this video:
The Four Stroke Engine
The four stroke engine is consistently taking over the ATV market. The power it can generate and because of its more fuel efficient combustion cycle makes it such a popular and overall better option. Why is a four stroke better though? What does it bring to the table that a two stroke doesn’t? One of the reasons a four stroke is more popular is it’s fuel efficiency. By taking four strokes instead of two strokes the engine can use less gas to complete its cycle. Another reason they are so much more popular is the power they can generate. Yes, it is true that a four stroke will generally be slower than a two stroke, it will have much more power and torque because it has more strokes to complete its cycle.
A four stroke engine is the same as a two stroke in the sense that it still has a piston, a crankshaft and a cylinder that work to complete the cycle. The piston moves up and down the cylinder and is moved by the crankshaft just like a two stroke. The difference comes in the cycle and some other parts.
The four stroke’s cycle:
During the first stroke while the piston is down an intake valve opens letting air from the atmosphere in the cylinder. A small amount of gas is also inserted by an electronic fuel injector. This is called the intake stroke.
In the second stroke the piston moves up and compresses the air, fuel mixture to create a highly combustible mixture. This is called the compression stroke.
In the third stroke the piston is shot down because the spark plug ignites this combustible mixture. This is called the combustion stroke.
In the fourth stroke the piston moves up again to send the burnt air-fuel mixture out the exhaust valve and into the atmosphere. This is called the exhaust stroke. When the piston reaches the top again the process restarts.
It takes one up and down motion or two strokes to revolve the crankshaft once. The amount of times the crankshaft rotates per minute is also called the RPM.
This process can happen dozens of times every second. It depends on the RPM which will relate to how fast the ATV is moving. At some points hundreds of strokes an happen every second.
For a closer look at how a four stroke works check out this video:
The Cost Differnce
Many people who own a two stroke bought it simply because it was cheaper. They are much cheaper mainly because they have less parts. The problem with them is the fuel inefficiency and the constant break downs and maintenance they require. A two stroke engine will be much cheaper but in the long run four strokes might actually end up cheaper because of the fuel efficiency and the low maintenance. If their was a problem with a four stroke it would definitely cost more to repair than a two stroke because it has so many parts but problems just occur way less often making it better financially.
Is It The Same for Manual and Automatic?
The same rules apply whether the ATV is manual or automatic. Manual and automatic just relate to the transmission which is the part of the vehicle that sends what you want to do across the vehicle. Transmission and the engine are very related and the ATV could not work without them but at the end of the day whether a two stroke or a four stroke is better isn’t really affected by the transmission.
