Mission accomplished with success and one improving right arm. I am so glad DA-50 is running perfect again. It was just as many of you had suspected. My ignition battery was low and the plug had fouled. Or, the ignition battery was just low, but I replaced the plug as a precaution anyway.

She started per the book the way she always has. I killed the engine and then restarted several times without any problems. I then leaned out the low end after having reset the needles to factory setting.

All is back to normal with more knowledge gained from the experience. Thanks for your help, suggestions and patience.