I recently put my Rap 50V in the air and it flies well, after breaking the TT50 in. I've noticed that regardless of how I set the carb mix, the engine runs rather rough, like it's cutting in and out. It's hard to describe. I wish you could hear what I'm talking about. When it cuts out, the tail twitches at the same time. I've had five heli's before, and have never experienced this problem, regarless of mixture settings. The problem seemed to vanish, for a couple of tanks yesterday, but then reappeared, later. By all other indications, it seems that the engine is properly tuned. It flies with plenty of power, it passes the pinch test, and plenty of smoke, to boot. A friend of mine, the local heli xpert, said that bad main shaft bearings could cause this. He said that at certain RPMs, the shaft could hit the "flat spot" of the bearing, and cause a slight drop in RPMs, thus causing the tail twitch. Although the heli is new, he recommended changing the main bearings, to play it safe. Has anyone had problem before?
Mike