I should have said modern day engines[&o] Ya got me However, Zenoah engines were not developed for R/C, but other industrial apps. With the exception of one very limited run Sachs, so were the Dolmar engines. It has become accepted that several engines now serve dual purpose and the second purpose is now listed. Same carb as the working version most of the time. In essence, only two companies have a specific listing for engines intended for RC. One of which does not make them any more and the other is frowned upon because it costs more

Find stuff for DA, 3w, DLE, BME, Taurus, and the host of other new additions to the market. By new I'm referencing the last 10 years or so.