I'm getting into the more technical side of my restoration now and today I did a resistance check on the Bosch coils. They are the original TJ12/1 type and I got about 3.6 ohms on the primary side and roughly 6500 ohms on the secondary circuit. Can anyone tell me if that seems correct?
I can find plenty of online info for general older points ignition coils but nothing for this exact one. It seems that the 3.6 ohms is good and 6500 is at the lower end of an acceptable range that goes up to about 9000. Having said that, Lucas bike coils only show about 4500 - 5000 ohms on the secondary according to Brit bike forums.