This product has been superseded by: 27-8172771. Product Overview. A well-sealed water pump is the backbone of a reliable cooling system, and the Mercury Water Pump Gasket (27-8172771) ensures just that. Designed for select Mercury outboards, this gasket forms a tight, durable seal, preventing leaks and keeping your engine's temperature in check. Whether replacing a worn-out gasket or performing routine water pump maintenance, this OEM part is built to withstand the harsh marine environment.. Crafted from high-quality, heat-resistant materials, this gasket maintains its integrity under extreme conditions. It's engineered to Mercury's precise specifications, ensuring a seamless fit that keeps coolant flowing efficiently. A leaking or failing gasket can lead to overheating, reduced performance, and costly repairs-this small but essential component helps keep your engine running strong.. Why It's Essential. Prevents Water Leaks - Keeps the cooling system sealed for maximum efficiency.. OE