90048-ZY6-040 Sealing (20mm) Bolt - Overview. The 90048-ZY6-040 sealing (20mm) bolt is an essential component designed for Honda marine engine systems. This bolt plays a crucial role in creating a reliable watertight seal within the engine, preventing leakage and ensuring the marine system operates efficiently. By maintaining a tight seal at key assembly points, it contributes significantly to the overall durability and performance of the engine. Engineered to exact factory specifications, this