Same max. RPM and CC of course. And if possible, an explanation would be nice. Thanks!

  • 1
    I’m voting to close this question because a google search gives berrymanproducts.com/two-stroke-vs-four-stroke-engines and the obvious is a 2-atroke has a power stroke every revolution while a 4-stroke does not. Also this is not maintenance or repair.
    – Solar Mike
    Commented Jul 27, 2020 at 6:20
  • 2
    @SolarMike - I think you are off base here. engine-theory covers this without issue. This is about the workings of internal combustion engines, so is on-topic from that standpoint. Commented Jul 27, 2020 at 10:32
  • @Pᴀᴜʟsᴛᴇʀ2 and a simple google search? as shown? Also are we talking a basic cheap 2-stroke or a race-tuned jobbie?
    – Solar Mike
    Commented Jul 27, 2020 at 10:35
  • 1
    @SolarMike - You need to read the help pages again ... and this isn't EE.SE. Commented Jul 27, 2020 at 10:37
  • 1
    @ SolarMike- I came to this website seeking professional insight- not condemnation for false accusations of irrelevancy. This is the closest stack exchange community to the topic of my question. I did the Google search, but I hoped that I could get a better, more in-depth explanation from some of the members here, and I got it. This website has been made to share knowledge, not to silence it. Consider this the next time you decide to close a question.
    – asdfghjkl
    Commented Jul 29, 2020 at 4:39

1 Answer 1


Theoretically, with all other factors being equal, the 2 stroke engine should produce 2 times the power of the 4 stroke engine. The reason being that the 2 stroke engine has twice as many power cycles as the 4 stroke per revolution of the engine.

Of course theory is one thing and it doesn't quite make it all the way to practice. Two stroke engines suffer from some inherent drawbacks that prevent them from achieving their full potential. The most significant of these is that they end up being less efficient due to several factors:

  1. Incomplete combustion due to the exhaust ports opening up while the charge is still burning.
  2. Incomplete "scavenging" of the exhaust gasses which then prevents a full fresh charge from filling the combustion chamber.
  3. Lubricating oil in the air/fuel mix which hampers the combustion process.

For some specialized applications, however, where low weight and relatively high power output is needed have used 2-strokes almost exclusively until recently. For example outboard boat engines have historically been 2 stroke. Handheld outdoor power equipment (chainsaws, string trimmers, blowers, etc.) still often use 2 stroke designs. Also many model/radio-controlled aircraft use 2 stroke engines.

  • I think the main reason for all of the uses of 2-stroke engines you mention are done so because the 2-stroke generally weighs less than a 4-stroke counterpart. Imagine toting around a 4-stroke powered chainsaw all day while in the woods ... argh! Model airplanes need to have weight savings, so this makes sense here as well. Overall, good answer so +1. Commented Jul 27, 2020 at 15:21
  • Check out the TS3 engine, an interesting one.
    – Solar Mike
    Commented Jul 27, 2020 at 15:32

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .