This Ridders 2-cycle vapor engine was designed by Jan Ridders, and built by Ron Schindele in 2017. The engine runs on fuel vapors generated in the tank and has a fuel/air adjustment where the knurled knob attaches to the tank. The timer assembly (located on the drive shaft) combined with the fuel/air adjustment, and relatively low compression, allows this engine to maintain extremely low revolutions per minute at idle. Mr. Schindele built the engine from plans available for download at Jan Ridders’ webpage.