Abstract: The Cometary Gears Output Rotary Engine (CGORE) has been developed from the Rotary Piston Engine. The Cometary Gears Set (CGS) output shaft replaces the traditional eccentric shaft. The CGORE has significantly better performance than the original or traditional rotary piston engine. The CGS has 3 gears fitting uniquely together. The CGORE has two systems of output shaft, one fixed at Internal Gear (No. 4) and the other fixed at External Gear (No, 6). When the rotor, rotated by the expansion of ignited gas, the power transmitted through the gears set converts the force obtained from the rotor into torque with higher efficiency than the eccentric shaft. As a result, the rotary piston engine with the Cometary Gears Set produces significantly higher efficiency of output torque, quiet operation, low fuel consumption, low exhaust gas temperature and reduces overall wear and tear of the engine.