The Tecumseh 36605K coil is for CDI ignition HS50 engines (1983ish and later.) What it does is advance the ignition a bit, for better performance on motors that turn higher RPM. Frankly you don't need this on a points motors, as you can do that yourself (assuming there's enough adjustment) by moving the magneto. Unfortunately the 36605K coil is hard to find. I would buy 20 of them if i could find them! but in abstinence of these, I was thinking of making an adjustable plate for the stock CDI coil, basically giving the same result as the 36605K coil. Just haven't gotten around to doing it yet...