Get a multimeter and check the resistance of the coil. Set meter to 20K resistance. Red test lead to spark plug boot wire and black test lead to the positive lug on coil, Should see 2 to 5 on meter,
Keep red lead in boot and move black lead to the ground lug. Should see 2 to 5 on meter.
Keep black lead on ground lug and move red lead to positive lug. Should see 0.1 to 0.2 on meter..

Also , check the flywheel to coil gap. If it's too large it won't trigger. Put a business card in between the magnets, loosen the coil bracket and adjust the gap to that thickness.