Enjoy pure sound of this incredible Moki radial engine. This is after 4 liters on 1:30, now 1:50 with Valvoline Synpower 2T oil (full synthetic) and with really big 34x14" Seidel Prop custom Z-37 Cmelak scale prop. Absolutely no problem for this big radial engine. Spin up is very fast and idle is around 700 rpm. Lowest idle is between 500-600 rpm, stable.