31231-ZY9-003 Brush Holder - Overview. The 31231-ZY9-003 Brush Holder is a vital component in Honda marine engine systems. It supports the electrical system by housing and maintaining the electrical brushes, which are crucial for ensuring proper electrical contact within the starter motor or generator. This ensures your engine's electrical system operates reliably and efficiently. Engineered to meet factory specifications, the brush holder guarantees seamless integration with existing parts, mai