Mine was giving me trouble for a while, all the electrical was fine. Turns out the carb had gunk in the jet and would barely run. It squirted fuel great. Then I would have a hell of a time starting it. Sometimes it would, other times it wouldnt run. But it ran fine for weeks up til it got gunked up and I figured it had to be something else because it ran fine before.
If its possible it could be electrical, Id disconnect the wires from the battery, only hook up the starter and run one wire to the positive side of the coil, and one from the neg side of coil to distributor. That way you know for 100% sure whether or not something in the wiring is the culprit. You bypass everything else completly.
Also Ive seen people on here before with 12 and 6 volt parts that were mixed up. Could that have happened?
You havent said if you removed the distributor? I wouldnt think it was off a tooth if it ran fine before, unless removed or broken?
Let us know! Jeff