well i just broke in my os .12 cv-x engine yesterday. Let me say i went exactly what you are going through. The conclusion i came to was that the instructions simply werent accurate for this engine. With the HSN at 2 turns out as recommended all it did was stall, if it started at all. Then i read that stalling when accelerating is actually a result of a lean engine which made sense as there wasnt much smoke out of the exhuast. So i richened the engine to 3 turns out 1/8th of a turn at a time and each time it ran better and better. Now its at 3 turns out and when i accelerate it no longer stalls, and it idles well. I didnt alter the idle needle at all so i can only conclude that its best to just adjust to needle to whatever works best. Now i will gradually lean it and see what happens. Hope this helps!