This was a great reply!

Back on the engine topic...

I have a Thunder Tiger 61 Pro (made in Taiwan), great engine now. It was very lean on the low end needle out of the box. Every expert at the field said "it's loading up at idle, lean the low end" and it was really frustrating trying to get it to start and run on a trainer. Finally went out really early with my brother, determined to get it running or toss it in the trash. Richened the low end more than a full turn, ran better. Kept richening in smaller increments for a while. When my instructor arrived tha day, he was absolutely amazed at how well the engine was running and how easily isstarted.

I also have
ASP 61 two stroke - This engine was so tight it had to be 'cooked' with a heat gun before it would start. So far it has only been bench run but it seems really good.
OS 70 Surpass 1 - It has about 5 tanks through it. It was 'good' out of the box and seems to get better and better with each tank.
OS 91 Surpass 2 - Still in the box but I have no doubt it will be great.

My brother has TT and Magnum 2 strokes, and OS and Magnum 4 strokes; all good. His Magnum 4 strokes took longer to break in than his OS; but, once broken in, they run great and are totally reliable.