Ihave two OS FX 46. Both are broke in. Ihave adjusted idle transition and works good. Have run and adjusted both engines on ground and thought I had them right. Have been doing this since 1995 and thought I was pretty good with 2 cycle engines. But the other night I had both on these engines on my two planes die in the air. Not sure if I was to lean or rich. I held them up in the air like we rc'er do and they both ran great. Sounded good when I was flying. Then at about mid throttle they died. Is that lean or rich problem. It was real hot and muggy. Any ideas? I have not been flying much in the last 4 years and I'm starting to pickup again. So it's been awhile since the engines have run. How does a bad glow plug act?. Thanks

Until now I usually don't have engine problems.