Originally Posted by gavin eisler
Magneto man, this has been a very educational thread, thank you for posting the beautiful pics and explanations.
Thanks very much for your comment. I've spent a lot of time trying to make sure the information is correct and verifiable, as well as understandable by people who may never have seen the inside of a magneto before. I've never seen information at this level of detail on the web or in print on the restoration of a magneto. Of course, this hasn't made everyone who sells magneto products or services happy. I'm reminded that John Wycliffe was burned at the stake for the heresy of having translated the Bible into vernacular English, taking the information out of the sole control of the priesthood to interpret for them. Although some responses have been irritating, it hasn't reached the point of a bonfire being started in my yard.

Originally Posted by gavin eisler
It is not clear to me how the Bosch points arm pivots, is the fulcrum point beneath the rounded tapering plate secured by the brass top hat washer, is it possible that the pivot bearing could introduce stiction and exacerbate the points bounce?
The pivot is a pin located at the ~10:30 position on the photograph, underneath the almost-vertical clip that has the elongated depression (elevation) in it. The points assembly has a ~1/16"-dia. pin that extends above and below it. At the bottom the pin is a slip fit in a hole in the brass plate. At the top the pin is retained by that elongated depression. That depression could have been a simple hole, but Bosch must have made it elongated to allow for the build up of tolerance (if it were a hole that was not located precisely over the hole in the plate below, the pin would be forced out of alignment and would bind).

Anyway, the points assembly pivots on the pin between the hole in the plate and the clip on the top. I lubed both locations with Lubricam, and at least by feel there was no stiction. That is, I could rock the points open and closed without feeling any resistance. Stiction would provide damping, and thus would help reduce overshoot, not exacerbate it.

The strobe is a very powerful tool for studying magnetos under actual operational conditions. Basically, the strobe lets me study everything in ultra-slow motion. Aside from floating points, if there is any jitter in what I see, that means there is variation due to some sloppy tolerance (which I then can look for and fix). If I were rebuilding a more modern magneto for a racing bike that needed to go to, say, 7000 rpm (3500 rpm magneto), the strobe -- plus different pulleys -- would let me make sure there were no mechanical issues up to that speed. I can't think of another instrument that would provide the same information the strobe does. This is a case where you need to see it, because that's what you're going to get.