1. A. You could be missing seeing the spark in the daylight or not having it grounded good to metal in the on position. I suggest an inline spark tester from Harbor Freight or your local Auto store.
B. Do you feel you had the plug grounded good to metal (cylinder/Etc) and tried to see in it in a dark area vs daylight?
C. Know that you have a plug that fires in another engine for testing vs using.
D. With the plug out, a fair spin of the flywheel should show you a spark from a good grounded plug or the plugâÂÂs wire lead close to a good metal ground (if the connectorâÂÂs metal is exposed close to ground or use a short bolt if needed).

2. Another Idea is to disable you on/off (unplug) to know it is not killing your spark.
   3. If you ever get past no spark, ck your air filter or remove it. Try with a light prime.
   4. Fire/Fuel/Compression and it should run.