19313-ZVL-020 Spacer - Overview. The 19313-ZVL-020 Spacer is an essential component for Honda marine engine systems, specifically supporting the thermostat cover system. This spacer is designed to create the precise gap required for proper alignment, sealing, and efficient operation of the thermostat cover assembly, helping maintain optimal engine temperature and reliability. Crafted to exact factory specifications, the spacer ensures seamless integration with existing parts, maintaining optimal