How hard could it to be to build a two-stroke internal combustion engine (ICE) from scratch ... For the carburetor he used a unit off Amazon, which turned out to have the wrong throat size ...

Although they still exist, 2-stroke diesel engines aren't all that common, and 4-stroke engines are what you'll commonly see ...

We’re introduced to the traditional two-stroke ... as an engine running on an alternative fuel such as hydrogen or ammonia, but we’re not so sure. If new free piston engines do take off ...