I'm new to the forum, I was actually searching for anyone else with one of these sleds as I just finished restoring mine!
I have a parts sled available that some pieces may come in handy for ya.
More to the point, I fought a no-spark issue for quite a while on the PTO side of the engine. After replacing condensers, and checking timing over and over again, I finally found that the PO had replaced the points and put one of the ring lugs on the points bolt the wrong way allowing the lug to contact ground, not allowing the condenser to charge... Once it was "bent" away from grounding out, she purrs like a kitten & starts on the first pull every time! (or from just a "bump" of the starter).
Kill switches on these certainly throw a wrench into the mix! While I was trying to diagnose the issues with the engine, I tested everything with NO connection to the chassis. This removes the possibility of a kill swx causing issues (just make sure your green, Yellow, and black wires from the stater plate are wrapped with electrical tape to prevent shorting!
I have had this sled sitting in the back of my barn for the last three years after refreshing the engine. When I tried to get it going back then, I threw up my arms. After testing the coils over and over, I finally ordered new condensers. When I got around to pulling the stator plate to replace them, I saw the ring lug touching the mount. Once I bent it out of the way... voila, full fire! It kills me since I work on point-ignition systems all the time, just one of those "duh" moments I guess..
I have completely rebuilt the harness in my sled now and have put on a larger carb. I think I could probably build one of these things in my sleep now! The only draw back is, living in Indiana, we might get 1-2 good weeks of riding weather
But, thinking back to the mid '70s around here... Anything is possible!!
Let me know if I can be of help!