If you’re looking at the engine pull start facing you at the top of the motor near the OHV valve cover there should be a black wire with a boot connected to your spark plug you’re telling me it’s missing?
It’s a electronic ignition or magneto. There are copper windings inside and as the flywheel spins there are magnets that pass the magneto and make a spark. The stock magneto should be fine unless it’s burnt out or not sparking. I recommend getting an NGK spark plug.