Have you tested that you are still even getting a spark now that it's clean and your flywheel gap is good? Should be able see it sparking following the standard method to test the plug outside the engine. Carb could be shot, could be something worse inside the engine itself. IF you fill the primer bulb, and shut all your needles (turn to full closed) does it empty the bulb as you pull to start it? Don't forget how many turns in you have to make to close them so you can return to last tune if it doesn't help.
Have you checked your killswitch. I Assume you have one because these things shouldn't be operated without it. IF that's preventing spark, could explain no spark when you do a spark test.