Please tell me what the different designations such as FZ, DZ, SPORT, and the previous designations on engines no longer being manufactured mean in terms of the engine and its performance. Also please indicate the power output of each engine.

Best regards,

Blacksheep

These designations have little to do with power, but are only used to distinguish one from another in terms of internal changes.

So just what are those internal changes? And why are you withholding the power rating?

I am trying to make a buying decision for a 140 and there are 3 or 4 YS models to choose from. And how do I compare those with other mfgrs. engines to make a wise decision for my requirements without knowing these specs?

There are only 3 140's. The Sport (same as the FZ), the 140L(discontinued) and the DZ. Horsepower for the Sport-2.75, L-3, and the DZ-3.25. They all make more HP than any of the competition, even their bigger displacement engines. If they didn't, why would YS engines dominate the aerobatics contests both in National and International venues?