Rich, that is not a stock set-up, I have the 9th bike off of the production line for US model year 1981, the first for the dreaded single coil dual output. Your previous owner probably had the original coil fail long ago ( the infamous crack-o-matic gray version), and didn't feel like paying $130+ US for a stock coil, and replaced it with a dual coil set-up. Nothing wrong with it as long as it works. The Dyna bolts right in using an adapter bracket as Justin showed. I got my coil from Motorrad Elektrik about a month ago for $80 plus $6 shipping. I talked to Rick Jones owner of Motorrad Elektrik, and he said that mine was the first upgraded OEM coil that he has heard of failing. My symptoms were hard starting below 55 F. and refused to start below 48 F.