Sierra 18-5825 Regulator/Rectifier The Sierra 18-5825 Regulator/Rectifier is interchangeable with the following: CDI 193-5204, Evinrude/Johnson 395204, 395391, Mallory 9-17203. Each Sierra product meets or exceeds the original equipment part it replaces. Sierra Regulator/Rectifier Meets or exceeds the original equipment quality Sierra part number: 18-5825 Interchangeable with the following: CDI 193-5204, Evinrude/Johnson 395204, 395391, Mallory 9-17203