Small Engine Troubleshooting Problems? Ask a Mechanic Now.
The coil and the magnet is all that produces the spark. How are you checking for spark? Plug has to be grounded to the metal of the engine, or it will not show. Also the coil needs to be within .010 of the flywheel magnet surface.
Can coil be mounted upside down? I don't see any other thing that would keep it from sparking. Other than a bad coil, but with original and replacement doing the same, not likley.
Is the coil grounded well? Remove it and clean the mounting ears and the engine block, so it gets good contact.
did you get spark?