Exactly WHICH Model Power steam engines are these? The first gen ones? Those had Mashima closed cans in the 4-4-0 and the 2-6-0, and I would not plan on taking those cans apart to clean out any carbon as that is likely not necessary. The internal gears are all Delrin and don't need oil, which will only help them accumulate dirt. If these are the engines you are dealing with, my advice would be to NOT remove the boiler from the frame, as it is very unlikely that anything you lubricate or clean in there will help, and there's a high probability of breaking off the connecting wires that go down through the frame to the contact strip on the bottom of the engine.
