BTW if any have problems setting very low idle on Acro 90 Jeti and Hacker C50 Comp configuration, try this. Switch two wires in the motor-ESC connection and turn rotation to the other side (rotation left in all cases I have checked). My both planes have a very smooth idle (500 RPMs) without stopping due to some hit shake noise, and have left rotation setting. Before I figured this out I have one of them with right rotation and cannot have an idle lower than 900 RPMs since it stopped and sound like something broke as it stopped. I hope this helps.