Things I've tried today:
- Cut and resoldered frayed plug wires to threaded contacts on distributor end
- Cleaned contacts on stator
- Cleaned contacts on distributor cap
- Cleaned and set points (they appeared correct already)
- Opened all four carb drain screws and verified gas present
- Visibly checked wires for breaks or grounding
- Inspected anti-reverse spring to see if anything got screwed up when it backfired. (Then when I checked continuity, remembered that I don't understand it well enough to know what to even look for...)
- Opened up the low speed adjustments