It makes really neat flames, and popping sounds when it is 180* out.
doesn't take long to figuire that one out though. It is how the engine wants to just stop when cranking.
Even if the distributor is 180* out, or 90, or 270, the wires can be moved on the cap.
It sounds like a distributor issue, unless it is vaccum, or fuel, or all of the above.
Having been a boatman for many years, it sounds like varnish has formed in the bowl. When this happens, flakes will float and at certain rpms, the flow will plug jets.
If I were Idameron, I would verify the firing order, locate #1, verify the timing, then take the carb apart and clean out the bowl, jets, and passages.
The old fuel used to go sour, and make a mess. The new fuel really evaporates faster, and leaves a grainey residue behind. This combined with the small varnish build up, produces flakes. In boats, this is a real issue.
I had an engine on my boat. It would idle like a bear, as soon as I opened it up, it ran on two less cylinders! I checked points, coils, timing, fuel filter, it went on, and on. As soon as I cleaned the carb. The problem went away. That was all it took. Really only cleaning the bowl and the lower jets.