No Spark

The only other inductive ignition coil that I have seen that was not wired internally like that, was on a 2 cylinder,2-cycle snowmobile of the 70s/80s, with a 180* crank. In that system; the secondary coil was isolated from the primary, and each end of the secondary went to a different sparkplug.Both plugs fired at the same time;one piston being near the top, while the other was near the bottom. The first was finishing compression, and the other finishing exhausting.I have no clue how those coils were internally wired, except that the two sides of the transformer did not have conductivity to eachother.The always non-metalic cases often(usually)had a ground lug. I assumed that,that type was center-tapped, cuz of the way the VOM responded. Occasionally I would come across a coil that did not have a ground-lug. I assumed that kind was shuffling electrons between the ends of the secondary wire. Of course that would mean that electrons on one end were jumping to ground, while on the other, they were jumping from ground. What a marvel.
Two-cycle engines,in general, are a marvel.
I think I have seen this type again on an EFI 4-stroke system, where the engine had half as many coils as cylinders. I just cannot remember the details.