I have a 1971 CT1 that I have been trying to get lights working on. The LED 6V headlight and LED strip light with signals and even brake work (but signals won’t flash yes I used two prong LED flasher relay….).

The gauge lights also work and are LED. I found the two open red wires at the tail light loom and added a 10a fuse in there which allowed my tail lights to function (not sure why it was removed). 

So, now; the bike ran before I started wiring lights. It ran great but a little rich so I dropped it from a 150 main to a 130. TBD on plug color. I tested the ignition coil and got primary of 5.3 ohms (should be 4.9) and secondary of 14.5-19k ohms (should be 11k).

I attached a pic of the 6V battery hooked up to the coil and you can see the spark but it isn’t blue. I don’t see any spark when kicking it however. Would you agree it needs replaced? Any other ideas ?I changed nothing on ignition but I did replace the rectifier, but that shouldn’t change anything???!!! Right?

Just flicking a battery across your single wire AC coil will flash at the plug so coil is likely ok. I'd start at the points, give a scratch if you think they're not contacting. Could hotwire it from the black direct to the coil to eliminate anything in the loom & ign switch. Wouldn't worry about discrepancies in your coil reading as plug cap adds 5k. Other than that i'm lost at the moment. See what the knowledgeable say.