90121-ZV4-000 Hex (6X45) Bolt - Overview. The 90121-ZV4-000 Hex (6X45) Bolt is a crucial hardware component used in Honda marine engine systems. This hexagonal bolt, measuring 6x45mm, plays a vital role in securing engine parts reliably to maintain the structural integrity and optimal performance of the marine engine. Manufactured to precise factory specifications, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Hexagonal bolt s