thanks for all your responses. i understand what you say that the YS should idle fine when adjusted correctly. that makes sense. and i really DON'T want to use a "bandaid". i have spent much time on the "test stand" getting it to idle consistently at about 2000 rpm. it actually does pretty well on the bench and will pretty well for up to 30 secs or so. it is when it is in the air that it does not idle well for any length of time. the engine has "died" after throttling back on approach for landing 10 out of 10 times. that is, throttling back to just above idle RPM. so there is seems to be something "different" when flying as compared to the bench scenario. the engine is mounted in the plane INVERTED. (the YS folks bench test it in the upright position). also there is ample air flow over the engine, it is not overheating. so i thought onboard glow might help. i havent ordered it yet. before i do that i am going to dismantle the engine and inspect the o-rings and seals, particularly the throttle barrel seal. replace as necessary and reassemble and try again. is just seems to me that the source of the "problem" must be simple but it has been a frustrating effort to resolve. i still may end up trying onboard ignition after "all else" fails. it is a relatively inexpensive item. i would choose the SwitchGlo Pro. again, thank you for your help.