I have a new OS 46AX and a Thunder Tiger Pro 46. Similar engines and have spent a LOT of time with them both on the test stand trying to "dial" them in to peak performance. I have only been doing this for about 6 months so far and have really, REALLY tried to find that "point" where everyone says it breaks from 4-cycle to 2-cycle and quite frankly, I simply have not heard it yet. I have sat there one day just practicing and shutting my eyes and SLOWLY leaning it in to see if I could hear some kind of change, and the ONLY change that my ear can detect is the RPM decrease. I KNOW that sound and once I hit it, I back off several clicks just as I should be.

Does anyone have any wav files they could share with us with a distinct transition from 2 to 4 cycle?