Every OS and Saito I've measured is .010". Big ones little ones, old one new ones... all about the same. As Motorboy said, it's how they lube the lower end. It is why we are able to run these engines on 10% oil and why 4C engine need less oil in general. All the major moving parts are lubricated not by a mixture of methanol and oil, but by mostly undiluted oil.

Since I mix my own fuel, there is also a lesson here... and that is, it is dangerous to assume that fuel and operating procedures for one type of engine will work for all engines. While fuel for an OS with .010" ring end gap may be fine with only 8 or 10 % oil, the next engine may be a Laser with .002" and need not only more oil in the fuel, but periodic supplemental oiling under the valve cover. What is good for the goose is not always good for the gander.

Bill