12 volts? Yes, that I know. The ignition switch seems to be the type you describe but using the 'start' part of it does not function, I have to switch it to 'on' or 'run', then use the foot pedal.
I know the carb is getting plenty of feul too, plus this secondary problem came on what I consider suddenly, it ran great then this.
I think my starter is original.
Ballast resistor? The orignal one on the firewall looks like.
The wires that melted were original, so I don't think they would be undersized, at least for their intended function.
Holy SMOKES... Funny.
