You might be interested to know that that famous permanent magnet vs. electromagnet split that the powersports industry exhibited for a very long time has an interesting history. The permanent magnet alternator (some training schools like to get fussy about what to call an alternator and what to call a generator, I'm staying out of that...) wasa actually first on the scene in (modern, postwar) motorcycling. Anyone remember the pushrod Brit biks with their zener diode regulators? Now that was something! They actually used two different forms of regulation, one was a headlight switch that cut in or out with the headlight an extra stator coil (winding) and the other was the zener, which was a diode wired directly across the battery. Yup. When the zener was activated, it was more or less a short across the battery terminals, and would have been a dead short if not for the fact that diodes have fairly high internal resistance. Think those zeners were long-lasting in this application? The Japanese came along and said, okay, we'll keep the switchable stator (most of Honda's singles and twins of the 60s and 70s) but we'll move the zener to merely a triggering role and in its place put a mich more durable SCR, and move it away from the battery to the stator. So instead of shorting the battery as the zener once did, the Japanse arrangement had the zener signalling an SCR which shorted the stator. This system continues on in the four cylinder Wing. The regulation was crude though, due to the available parts, and so in the 70s excited field, or to us, electromagnet systems such as those on cars emerged as the leading system and this continued into the early 1980s (not on Wings of course, but almost everything else). Until two things happened. First, it was determined that electromagnet systems were no more reliable than permanent magnet and no more economical to manufacture, and two, that the electronics for permanent magnet systems had by then improved (giving us instead of on/permanent magnet regulators more finely trimming FET and others), and so by the mid 80s permanent magnet charging systems were back in majority again. Kind of like how the CV carb went from rubber diaphragm to metal seal and back to rubber diaphragm, and for much the same reasons.
