50403-ZV1-000 Hook Return Spring - Overview. The 50403-ZV1-000 Hook Return Spring is an essential component in Honda marine engine systems, primarily used in rigging and throttle/shifter mechanisms. This spring supports the mechanical motion system by enabling components to return to their original positions after actuation, thus ensuring smooth and reliable operation of your marine engine's controls. As an OEM genuine part, it is engineered to meet Honda's strict factory specifications, dimensi