That solenoid on the genny operates in a way opposite most mower solenoid. When you turn the engine off it uses the residual power being generated to close the solenoid, when the engine stops it reopens.
In other words a mower solenoid uses power to open it, but on a Generator such as this it uses power to close it.
In other words a mower solenoid uses power to open it, but on a Generator such as this it uses power to close it.