These single-cylinder diesel engines operate at incredibly low RPM and have an impressive appearance.

      I appreciate a large diesel engine just as much as anyone else, but they aren’t always practical. Although I’d love to have a V16 two-stroke Detroit or something similar, I have no real use for one—I simply don’t need it. However, I could definitely find a purpose for these Yanmar single-cylinder diesels, which are water-cooled, hand-cranked, and content to run at almost zero rpm.

      It's convenient that these engines don’t require a full garage for storage; they can fit on a tabletop or a pushcart if necessary. What's surprising is that they’re not new at all. They continue to be manufactured, although mainly for markets other than the U.S., where small engines are being phased out for emissions reasons, particularly in California.

      Nonetheless, I believe these engines deserve attention, and a recent viral video on Instagram and TikTok shows many people are curious about them:

      Commenters compared it to an ancient hit-and-miss engine, which isn't quite correct. Those older stationary units were designed to operate at a steady engine speed, while the Yanmar in this video is just idling at a lower rpm than intended. The ability to idle so low without stalling is quite impressive.

      After seeing that video, I started exploring Yanmar’s website for Indonesia to learn more about the TF160 and similar engines; there are various other series for different uses. The engine featured is a horizontally arranged four-stroke with direct injection. It has a displacement of 0.857 liters, a bore of 4.02 inches, and a stroke of 4.13 inches, making it slightly under square for better fuel efficiency and low-end torque, peaking at 2,400 rpm. Weighing in at nearly 310 pounds dry, its dimensions are 30.2 inches long, 14.94 inches wide, and 24.5 inches tall.

      The TF series includes smaller engines starting with the TF65, a 382cc engine suitable for farm equipment like tillers. On the other end of the spectrum is the TF300, which is nearly 1.5 liters and ideal for marine applications. Regardless of the size, all of these engines are direct-injected and water-cooled, which is quite impressive.

      Additionally, there’s the compact NL series, consisting of two models: the TF85NL and TF105NL, with engine sizes of 493cc and 583cc, respectively, focused more on agricultural use. They really do resemble a tractor without a seat or wheels, don’t they?

      Some enthusiasts even modify these engines. Take a look at this one with its long, colorful pipes:

      The smoke billowing from the exhaust clearly illustrates why Yanmar doesn’t distribute these engines in the U.S. Instead, the company markets the TF series in Indonesia, Malaysia, Singapore, the Philippines, Saudi Arabia, the United Arab Emirates, Kuwait, Bahrain, and Taiwan. The NL series appears to be available only in Indonesia. Occasionally, these engines can be found for sale on eBay, such as the TF160 listed for $2,600, plus air freight from India.

      If you need a small industrial engine in the U.S., there are other alternatives that you can purchase quickly without any hassle. However, that doesn’t diminish the intrigue of these engines to observe and watch in operation. Machinery varies worldwide, and while you can obtain a Kohler diesel here rapidly, it just wouldn't have the same appeal—even if regulators don’t consider that.

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