my first duster.

Vent: take off the gas cap, stuff a rag in it; bet that's not the problem. Start by finding intitial timing, and Total. Start by bringing up initial to 16, drive it (don't run it up past 4000, or less, if you hear ping). If that helped, time to get in the dissy, first.

Then time to fix carb. Probably a combination of both.