Hi Uladzimar,
the TL-Ultralight constant speed controller box is partially faulty. Ask TL for a new one. Alternatively if you know someone else with a Sirrus or Sting swap one around.
It is normal for the controller to cycle and settle as the PID copes with changes in rpm but this graph shows the PID id not working. I believe even in manual mode the constant speed box does a pseudo straight through control and in eithe mode this data indicates the box is faulty.
Glenn
