I'm working on a '72 LB 5239A. D-408. I simply cannot get a spark out of it. New coil, new points/condenser, new plug wire, new plug, etc. I have checked the point gap three times and it's within spec, the coil air gap is good. No spark with or without the plug. The flywheel magnets are a bit rusty from the mower sitting outside for around 20 years, but I sanded them to the best of my ability and they are still strong. What am I missing?