90004-ZY9-M01 Stud (6X40) Bolt - Overview. The 90004-ZY9-M01 Stud (6X40) Bolt is an essential fastening component specifically designed for Honda marine engine systems. This stud bolt supports the secure assembly and mounting of various engine parts within Honda's marine series, ensuring the engine remains operational and reliable under demanding marine conditions. Engineered to precise factory specifications, it ensures seamless integration with existing parts, maintaining optimal performance a