17371-ZY6-020 Muffler Case - Overview. The 17371-ZY6-020 Muffler Case is an essential component of Honda marine engine systems. It supports the exhaust system by housing the muffler, which plays a crucial role in reducing noise and directing exhaust gases away from the operator and the environment. Designed to integrate seamlessly with factory components, this part helps maintain optimal engine performance and durability by ensuring proper exhaust management.. Key Features. OEM Honda genuine par