Thanks for the answer. You did your homework. But I beg to differ in what you consider the best engine. A very good engine to be sure, but the best might be an over statement.

You will get the same answer from different owners of different engines.

Not too long ago, the saying was if you want a good 100cc engine, get a ZDZ 80 single.
Now they have the 100 NG (Better) and also in the 50 cc class, you also have the NG series.

Don't get me wrong, I only hear of good things about DA, but then that's what I hear about BME, and ZDZ and 3W, it depends who owns them.

Roger