Generator trouble

This is the 2nd time I've had the regulator in my Briggs & Stratton generator fail. It's really starting to bug me.

I'm seriously considering building my own so I can put in higher rated components and actually repair it when it fails.

The factory replacement is potted and costs $70 for about $5 worth of parts. All it's doing is taking voltage from the excitation winding, rectifying it and putting it onto the brushes, and regulating the main coil output voltage by changing the voltage on the brushes. Really nothing to it.