Sorry for the long post, but here goes. It has been a long time since I tuned it up so I decided it was time. Hard starting and "spitten and sputering". I replaced the points with Blue Streaks after the A&I points wouldn't open without filing the holes. The Blue Streaks needed the end holes filed to get them adjusted to close. Adjusted to .015.New condenser, rotor and cap. No spark. Around 3.5 volts at the top terminal on the coil. The test light blinks when the key is on and the engine cranks telling me the points are opening and closing. Ohms from the top terminal to the point pigtail is 5.9, to the cap terminal is 2.5 ohms. Within the range from YouTube vids. With the cap installed and the rotor pointing straight up, I have continuity from the contact point on the cap to the rotor. I have had 3 different coils installed, including the new one I bought yesterday(also A&I Industries). I've had at least 3 different condensers on it. The bushings are both tight and smooth. New battery last year, fully charged with a maintainer. Help! I'm running out of ideas.

Sometimes it pays to just walk away a while. That's where I was last night. This morning I raised the coil off the distributer to inspect the two connections underneath. I had my mirror positioned to see better. The pigtail was straight as usual, the tab to the cap appeared normal. I reattached the bail to hold the coil on. I turned the key and hit the starter with a 12volt jump. It instantly started!!
I have no idea what was out of wack. I always use a 12volt to starter jump when having problems since it gives you a full 6volt to the ignition. The bail that holds the plate in the distributer is close to the pigtail and could have been shorting, but it didn't look like it. I had the coil(s) on and off a dozen times. I did nothing different this time. All my N's have the front mount distributer, and I've never had this problem before. I wish I could say live and learn, but I still don't know the problem. All I know is that it runs!