Have it on a coffee warmer with coins stacked on it to raise the engine to slow the engine down. Works continually and is fun to watch.
Out of the box it wasn't working. I had to balance the piston and flywheel so that it moved a little more freely. I moved the wheel so that the piston was at it's highest position, lifted off the cylinder to let air in, then closed the cylinder. After that I put it on top of my CFL table lamp and it was warm enough to get it going.