Even though a plug may throw a spark when its sitting on the engine where you can see it, it may malfunction in the engine. Never been able to fully explain it, but it happens. If compression, fuel and fire seem OK, its gotta be something you haven't tried yet. Make sure cap, rotor, plugs and wires are dry and in good shape. Give the engine a snoot of starting fluid the first time you go to try it, to prevent the chance of re-flooding. If the compression is good, and the starting fluid doesn't wake her up, then its gotta be ignition.
