I find these little engines tend to run at a fast idle, usually with 2700rpm being a good reading.
LSN is normally set to around 1 3/4 turns out and the HSN is around 1 1/2 turns out (set with throttle at WOT).
Try 10% nitro for fuiel with lot's of castor in it so the engines will break-in (they take ages with synth oil). Usually they need around 3 liters of fuel to have a reliable idle and being almost broken-in...