[rwest]

Sounds like you may have found your culprit- I once had a intermittent Permatune box that drove me nuts trying to verify that it was indeed the problem.

If the replacement CDI box doesn’t solve the problem, I would hook up a timing light every time I tried to start the engine to see if you have spark during the no start issue. Slight pain, but pretty simple way to track down if it’s an ignition problem.