Physics teacher and student. Robotics and Automation enthusiast.
· Ghaziabad, India
You need to modify your diagram.
You need to install a centrifugal clutch mechanism between the rotor hand of the mass and the rotor hand of the flywheel.
The electricity generator should be coupled (with gears) not to the flywheel directly but to the rotor hand of the flywheel. In fact the other side of the flywheel a smaller than flywheel wheel has to be attached and it should be the one from which you need to harness electricity.
If you want i will upload a drawing as i have in my mind.