DIY diagnosis and replacement of a regulator/rectifier on a 2008 Yamaha 150txr 2 stroke outboard; Gauge showed less than 12 volts while running; No change with RPM; Good fuse and connections; Discolored regulator/rectifier found; Replaced with OEM part; Test after install showed 13+ at gauge and 13.5 to 14.1 volts at the battery; DIY Success!