[Green 912]

Generators are simple in function and tend to be robust. 3 in a year, you might want to look as to why. Have you checked the regulator function and all its related conections, and the battery and its wires?

On the generator, check all conectors external and internal, the brushes, winding ohms through and no shorts to ground.

Having to rev up to kill the gen light can be a failing (or just sticking mech type) regulator, a bad connection, a bad battery and a bad generator. (Or some kind of major elec overload like a hardwired 9000watt sub and 100amp driving lights)