The light test is a way to verify that the points are opening and closing and that they are making good contact. You can set your timing that way too. It's known as static timing. Black with white tracer wire is "hot". Solid black goes to ground at the points plate. The other three wires follow through the engine case to the wiring harness via "bullet" connectors. They will be stuffed behind the carb and its air cleaner. Check those connections.
So, how did you test the condensor and high tension coil? There is still the "exciter" coil to check, which is under the flywheel.