50539-ZW4-H10 Spacer (19.4X6) - Overview. The 50539-ZW4-H10 Spacer (19.4X6) is a vital component in Honda marine engine systems. This spacer supports the power trim and tilt system, playing a crucial role in maintaining precise alignment and proper spacing between mechanical parts, which is essential for the smooth operation of your marine engine. Engineered to match factory dimensions of 19.4mm by 6mm, it ensures seamless integration with existing components, maintaining optimal performance and