Small Engines (Lawn Mowers, etc.): Small engine repair, edger, 2 stroke engines, gasoline power

Question
Weedeater edger gasoline power. No prior trouble.

Suddenly refused to start or run. Replaced & gapped spark plug, cleaned air filter, no help.
Took air filter off, no help. Tried all permutations of choke.
Checked for spark at plug, good spark. Put fuel in cylinder, won't start. Ran a bit once, a lot of white smoke, died and no start.
Compression seems OK with thumb, put oil in cylinder no help.
Adjusted carburetor screws a bit, no apparent effect.
I'm out of things to try. Any suggestions?
Thanks.

Answer
Hi Jim,

2 stroke engines are difficult when they have problems.
The carb may need rebuilding but if it doesn't run when you add fuel to the carb intake then the carb may not be the problem.  There could be a bad crankcase seal, causing an air intake leak or a carbon plugged exhaust port and/or muffler.  

Please let me know what you find.
Michael