40104-ZW9-830 Oil Case Grommet G - Overview. The 40104-ZW9-830 Oil Case Grommet G is an essential component in Honda marine engine systems. It functions as a rubber grommet designed to provide a precise seal for the oil case, preventing leaks and contamination that could compromise engine performance. By maintaining a secure barrier, this part supports the oil system's efficiency and protects internal parts from damage, ensuring reliable operation over time.. Key Features. Rubber grommet designe