Bill, for clarity please explain the “RA” adjustment.
The “octane adjuster” thing?
My two cents - for the kind of thing the OP is doing here….
Just set the idle down as low as it will go without dying. See if a little more advance (loosen clamp and twist dizzy) makes it pick up and run smoother. Find the sweet spot and then try a restart. If it struggles to start you might need to back it off a bit.
Worrying about a specific RPM or a numerical timing value can come later. My thought is just testing the timing theory.
