Hello all, I have a few questions about the Bosch Magneto on my Buick. I believe it's a ZU4 but that is only going by pictures. The engine has no spark so I am trouble shooting the issue. I came up with both sides of the points are grounded when the point are open. Just an fyi the wire to the key is disconnected. I can see that the fixed side of the points is supposed to be isolated from ground. I have found that the center bolt that holds the fixed point side is what is going to ground. There is no insulation on it so it is obvious that when it gets screwed into the mag housing it is grounded. I was wondering if the tapered part of the bolt is supposed to have some sort of insulation? Or am I missing something else ? Here are a couple of pics of the points and parts. I have circled the tapered part of the bolt in one picture that I am questioning. Thank you for any help.