30421-ZY6-010 Cover - Overview. The 30421-ZY6-010 Cover is a critical component in Honda marine engine systems, specifically designed to protect the electronic control unit (ECU) of Honda BF135 and BF150 outboard motors. This cover serves as a robust housing that safeguards sensitive electronic parts from environmental elements, dirt, and moisture, ensuring reliable operation and longevity of the engine's electronic system. Made to exact factory specifications, the 30421-ZY6-010 Cover integrates