I've got an old Bobcat with an air coooled 4 cylinder wisconson engine.
Died on my wife the other day, she was cleaning snow at home while I was doing it at work.
A little investigation showed no spark. Old style points ignition, haven't worked on one in a LONG time.
Figured out the spring that makes teh points make contact was broke, so it looked like an easy fix. Had to pull the distributor to get at it, marked everything so I could put it back together. Went to the box of parts that came with the machine, found 1 condenser, three sets of points, 2 caps, 3 rotors. Put a set of points and condensor in it, set the gap to spec, and put it all back together.
Still no spark.
To make a long story short, points are just a ground that's timed. THEY WEREN"T GROUNDING! NEW POINTS!
Had to take (after removing the distributor again and using an ohmeter to see if they were doing thier job) sandpaper to a brand new set of points to make them make a good contact.
Put it back in, machine fired up on the first rev.....
Frustrating! Don't take for granted that new parts (Delco no less) are going to work. Check it!
that is precisely why points are no longer used in new motors...
-Owen
I always used to stick a fingernail file in there for a few strokes to make sure they had a good clean contact surface. Like you it's been a long, long time since I worked on anything with points.
I've had that happen a couple times with points that I've had sitting around for a long time.. (My golf cart still uses the darned things

) But of course with points, it's always best to have that spare set around.. I've been scarfing the little packages of desiccant they put in with electronics and such and throwing them in some tupperware with my points for storage...
But then again, with the quality of new and reman parts now days, I'm totally unsurprised when I get something that doesn't work.. Sometimes twice...
I still run points in XT and TT 500 Yamahas. I much prefer the points over the CDI unit in, yet, another XT 500. The CDI ALWAYS requires a maximal kick to make ignition happen. The points will go with a slight kick instead.
All this matters with age-related cartilage in the knee and hip!
I still run points in XT and TT 500 Yamahas. I much prefer the points over the CDI unit in, yet, another XT 500. The CDI ALWAYS requires a maximal kick to make ignition happen. The points will go with a slight kick instead.
All this matters with age-related cartilage in the knee and hip! 
gotta do whatever it takes to make them thumpers easy to start..