I have been meaning to ask , what is the idle speed that most consider to be an acceptable minimum? Isn't it going to be dependent on many factors like prop pitch, airframe drag and weight, field conditions? It seems everyone is shooting for 2000 rpms. However it seems to me that most engines will idle more reliably closer to 2500. I have found on rare occasion some that will idle at 1800 but most depends on the carb setup. For example a 10X6 at 2000 says 9.9mph but only .11 lbs of thrust , a 10X5 is 8.2 and .1 lbs, 10X4 6.6 and .09.