The patent office has never issued a patent for an over unity engine (one that produces more power than but in, eg. a perpetual motion machine). Obviously the three patents they refer to say nothing about this little tid bit.
Try googling and looking at motors that run on water where the water is converted to hydrogen and oxygen. Its possible, but in the long run, it takes more energy to break apart water than can be gained putting it back together (burning it as fuel in an engine). You are losing something if the engine gets the least bit hot since the heat is caused by combustion and motor friction. I'm sure the Johnson motor will produce some heat, thus can not be a perpetual motion machine.