Abstract: An internal combustion rotary engine in which only a single spark plug is utilized to ignite fuel/air mixture located within a single cylinder. Within the cylinder is located a pair of pistons mounted in a back-to-back relationship. A power output shaft is attached to the cylinder. The pistons connect with a connecting shaft assembly which extends through an access opening assembly formed within the cylinder. The cylinder is rotatably mounted within the fixed engine housing. The connecting shaft assembly connects with an auxiliary power output shaft. An appropriate fuel/air inlet port is provided within the fixed engine housing and there is also provided an exhaust port. Each piston incurs a power stroke for each single rotation of the cylinder.