2 Stroke v. 4 Stroke

Ever wonder what the difference between a two stroke and a four stroke is?  There is a great difference between the two, both a completely different systems that most do not quite understand.  Most know that four stroke engines are the new craze, in fact, there are more four stroke engines on the market than two strokes.  Out of the major engine brands, there is only one manufacturer, Evinrude.

When you hear the phrase "two-stroke", most think of a smoke machine that requires the passengers to wear a gas mask to be comfortable.  Not by today's standards though, Evinrude has completely changed that perspective.  In fact, if your Evinrude is smoking, you may have a problem.

Before I start explaining the difference between the two engines, take a look at this video.  Though this video was created by Evinrude to advertise their engines, it does not seem to give the Evinrude any clear advantage over the competitor.  The test is showing what two stroke engines are known for, torque, along with many other things that I will cover later.

Here is another example of the torque that is produced by the Evinrude.

What Makes Them Different

• Well clearly from the video above something is different.  Apart from the wonderful sound that a two stroke makes, the point that the video is showing is the astonishing amount of torque that a two stroke has versus a four stroke.  
• Two stokes use oil.  Rather than using oil to circulate through the engine to lubricate it, the oil is mixed with the fuel before the engine to have the same effect.  
• Two strokes are often lighter.  As in the video above, the Yamaha weighs roughly 480 pounds, the Evinrude weighs about 425 pounds depending on the shaft length.  For a boat, you need to loose all the weight possible.  
• Evinrude requires no scheduled maintenance for 3 years or 300 hours, which ever comes first.  This can greatly lower the cost of ownership.  As for the Yamaha or any other four stroke, they require at least an oil change every year.  

How a 2-Stroke Works

There are three different types of oil that can be used with the Evinrude that each have their own special characteristics.  Check back later for a comparison.