I noticed the past few flight that as I lift the craft with full thrust it starts to turn CCW. When i stop, the craft turns violently to the forward direction. I have tried several different props (new stock and cheap ones from China) and it acts the same. I am suspecting a motor might be going bad, but I don't know which one. Also, I have also received an error several times about "max motor speed reached". But I don't know which one(s). Any ideas?