Here's my theory then...

The factory engine to body ground does not exist. So I don't have a good ground for the engine, causing this new starting problem. Since this isn't a new problem, the ground has been gone forever to my knowledge, this could be why over the course of my owning it runs sporadically poor. If the engine is not grounded the spark plugs won't give off a very strong spark leading to poor running. Add a good ground, the starter will function better, the spark will be better so the engine should run better. Right? Perfect sense to me!