Thom, I’m going to try and explain a little bit about the coil. I am by no means an expert. I’m going by memory from a little while back. Here is a YouTube video showing how I power tested the RBM coil with a merc o tronic ignition tester. By looking at the video I will be able to make position reference where to test the coils primary winding and secondary windings with an analog meter. Using the analog meter you are testing for continuity only. That should just give you idea if the primary and secondary windings are currently intact and probably will give spark.
https://m.youtube.com/watch?v=eq4RnwBaLS0
When checking for continuity, it does not matter where the red or black leads go. In the video, it mattered where I put the leads because I was power testing the coil. I was testing the least amount of amps it takes to jump gap and produce a spark. According to the authors in the Southern Ontario RBM magazine, if the coil power power test uses 2amp or less to produce a consistent spark with merc o tronic tester, then the coil was deemed good.
But we are focusing on checking for continuity of the coils primary and secondary winds. SO, watch the video first so you will understand where I am going to reference.
Check the primary winding
Note where I placed first red lead with the merc o tronic. Place the red lead from the analog meter on the square hook exposed near the coils primary winding. That is also where the coil connects to the condenser. Safely if you can isolate the coil from the condenser. Place the black lead on the magneto plate. You should get good continuity.
Secondary winding testing
Leave the red test lead in the same place and place the black lead where the hi tension spark plug wire should connect. If you are using the 1K scale, then you should get about 2 to 4K ohms resistance if the secondary winding is intact.
I’m sorry if this is not quite the procedure, because I am going by memory. If someone has not properly addressed your query, then when I get back next Friday I will post a video testing the RBM coil.
We have good group of RBM experts, hopefully one will chime in.
