31620-881-A02 Regulator Rectifier - Overview. The 31620-881-A02 Regulator Rectifier is a critical component within the Honda marine engine electrical system. It plays a vital role in converting the alternating current (AC) generated by the engine's alternator into a controlled direct current (DC) output. This DC output is essential for charging the battery efficiently and powering the boat's electrical systems reliably. Designed for Honda 6HP BF6 BF6B SGD and 8HP BF8 BF8A outboard motors, this r