Ditto that - life is much happier at low throttle settings with the leaner idle settings. The engine does not cook from running close to full lean at idle like it does at full throttle - there is simply not that much heat being produced. The engine should not speed up much at all if you pinch test at idle - perhaps just a few rpm then it should quit in, oh, 2-3 seconds [ever notice how things work when you do them but describing the procedure in writing is a challenge?]. Do you pinch the fuel line at idle to check this? Some folks only pinch test at WOT but I find it a vey helpful tool at idle as well, once you get an ear for it.

I too have had more engines quit at low throttle settings or acceleration from too rich an idle. Once the idle mixture is correct adjust the idle rpm with throttle setting, not mixture. The benefit will be that if you are on an approach and things go awry, you have a better chance of accelerating quickly wthout quittng rather than having the engine stumble from beng too rich.

MJD