Looks like I've stripped the threads of the linkage that connects the carbs together, which is the same linkage that connects to the accelerator. What really really sucks is that I can't even FIND this piece on any of the usual places. It's not in the diagrams, it's not in the catalogs, etc.
Crap crap crap crap CRAP.
So I'm going to have to get creative.
My idea is to get a brass rod of the right diameter, thread the end, and then... somehow...connect it to the existing mechanism. Wish me luck...