90549-ZY3-000 Shim B (2.80) - Overview. The 90549-ZY3-000 Shim B (2.80) is a precision-engineered shim designed specifically for Honda marine engine systems. This critical component functions as a thin adjustment layer within the mechanical assembly to maintain precise clearance and alignment of engine parts, ensuring reliable and smooth operation. As a genuine OEM part, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Shim B (2.