Re: Problem with substituting OMC coils in an antique

[George Emmanuel]

Thanks for the suggestions! Since I posted the issue I went to my shop (I was working on the mag at home) because I could only do a battery test at home. Once at the shop I went through the same procedures and I could only get one plug to fire using the flywheel, and that was with both grounded and one green wire off. The coil with the green wire attached would fire and it did that on the other coil if I disconnected the previous and connected the other. But if I attached both green wires it would not spark. So off came everything and I tried parallel and in series wiring with no results.

Now I might add that these coils are NAPA and previously coils I got at NAPA (Sierra) were made in Germany,—now they are from China! I can’t wait to see Outboard Jim @ Tomahawk to stock up! So being persistent I thought maybe there could be a polarity issue between the green and black wires, and sure enough when I wired the mag in parallel as before but switched to one green and one black to ground and the other green and black to the points HOT FIRE!!

So now I’m wondering if the issue is reverse polarity (improper winding in the coil) (hecho in chino) or does having the same polarity between the coils cause a cancelling of the magnetic field? Does trying to use a battery also affect the magnetic field? At any rate I’ve got a clean job and hot spark.