There is a sometimes acrimonious discussion in the thread I posted on the suitability of the Brightspark conversion. Much of which is more than most of us wish to know. Certainly the author of the article is not keen.
From my reading the conversion will work for a time.
The question is how much time. 5 hours 50, 500, 5000 ? There is no hard data presented.
I agree few of us will rebuild a mag as demonstrated in the article. But it gives a lot of information on how to evaluate the quality of a rebuild. My own experience is that many rebuilders do not properly address the mechanical aspects of the rebuild. Which is precisely what can lead to the large errors in opening times of the points and timing discrepencies between cylinders described above. I destroyed two sets of pistons because of this issue so these days I verge on paranoia when it comes to ignition timing :roll: .
While the author of the linked post is not given he is actually a PhD physics professor at an American university with a demonstrated track record of extremely high quality rebuilds of mags and complete machines. I would rate his work at absolutely first class. Unfortunately not in the business of rebuilding mags except for his own machines.
I can add a third reason why the points gap can be different. The shaft of the rotating armature is out of parallel or off centre with respect to the body of the magneto. The problem with my own mag was the shaft was out of parallel. This could be seen as a variant of Slick's first reason. But in this case its not the cam ring which is not central but the shaft.
I also agree and support Slick in his posting above.
