I did get it running. The problem was a loose receiver antenna! The plane would get a bit too far and go to failsafe which would close the throttle, then with no vibration I would get control again and would land and find the engine would start right up and run. Now for your trouble. You are remembering that the air bleed is opposite of the main needle correct? I am not sure how you tune it but YS are certainly unique in that regard. Assuming it is tuned well and not knowing many other factors, I might take a very wild guess and say try a new OS plug. I find they often go bad during a good break in. I have not checked here much but I will follow up with this for you.