A new engine broken in with 5 full tanks as per instructions and flown maybe 5 times so far. The engine was tuned to peak rpm less some 300 rpms and mid range adjusted to be steady on the 4000 rpm range .Low speed also adjusted to be 2000 rpm and steady. The problem is when the engine is running full speed (10700) and snapped back to idle the rpm would instantly drop to 1600-1700 and immediately recover to the 2100 rpm or thereabouts and stays steady. However the engine does quit sometimes when throttled back and reaching the below 2000rpm rage before going back to the normal 2000 rpm range. It is also quitting in flight when the throttle is turned down to idle. Any clues please. Thanks

If it is dropping below 2000 and then recovering back up to 2000 I would hazard to say you are a bit lean on the bottom end.