I skimmed through this thread and may have missed a link to the first thing that came up when I Googled "overbalanced wheel."
http://www.lhup.edu/~dsimanek/museum/overbal.htm
And then there's this.
Ben Thomas building a copy of "Techstuff's" gravity wheel
And also this.
Perpetual Motion
So is the idea that of a flywheel on some kind of gravity-based steroids? Because if that's what it is, I tried that a dozen times when I was 10 years old and fascinated with the single cylinder engine an old sawmill used. It occurred to me after a few attempts that the designers of the engine probably wouldn't have put the cylinder on if the flywheel had been enough by itself. So I attached my flywheel to a crude electric motor I had made and still have, and a homemade generator, which never generated much energy. When that stopped being fun, I went back to finding new ways to kill grasshoppers and baby birds. Weights combined with hay derricks often seemed to do the trick. Feed grinders and corn shellers were good too. But nothing beat a rubber band and a firecracker.
I have since made my peace with nature, and have allowed that trying to design a perpetual motion machine probably isn't any more natural than blowing up baby birds by sticking firecrackers down their throats.
--lemit
p.s. Sincere apologies to all animal lovers.