Abstract: A gravity-driven engine (1) having at least one pulley (2) connected to a pulley support frame (33), a spring (24) connected to the pulley support frame (33), an output shaft (20) having a fly wheel (10) located thereon and wherein the at least one pulley (2) is connected to the fly wheel (10), a lever arm (6) rotatable about the output shaft (20) and a weight (5) rotatable about the output shaft (20) and in connection with the lever arm (6). When the weight (5) descends from a zero degree vertical position by gravitational force, the spring (24) compresses as the weight (5) rotates in a circular manner to approximately 345 degrees. When the weight (5) is approximately 345 degrees from the vertical position, the spring (24) decompresses and makes contact with the lever arm (6), thereby pushing the weight (5) the remaining 15 degrees and resulting in an overall rotational torque caused by gravity which thereby causes rotation of the output shaft (24).