16891-ZW2-900 Bystarter Tube - Overview. The 16891-ZW2-900 Bystarter Tube is a critical component of the Honda marine engine system's starting mechanism. It plays a vital role in facilitating the proper operation of the bystarter system, which is essential for smooth engine starting and reliable performance on the water. This tube ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Designed specifically for the bystarter system in Hond