90301-ZV0-000 Wingnut - Overview. The 90301-ZV0-000 Wingnut is a precision-engineered fastener used within Honda marine engine systems, primarily supporting rigging and accessory assemblies. Its primary function is to provide a reliable, tool-free tightening and loosening mechanism, ensuring components remain securely fastened during operation. Designed to maintain system integrity, the wingnut aids in permitting quick adjustments and maintenance without compromising the safety or functionality