18-3606 Thermostat Kit Fit for Mercury Marine 200-300 HP Outboard Motors, Compatible with Models 885599003 885599004 27-850318 27-8503181 & Sierra 18-3535 18-3675
Precision Fit & Guaranteed Compatibility: Replacement thermostat kit designed for Mercury Marine 200-300 HP outboard motors (2000-2024 models). Perfectly fits OEM part numbers 885599003, 885599004, 8855991, 8M0057307, 27-850318, 27-8503181 and Sierra 18-3535, 18-3675, 18-3606.
Durable Corrosion-Resistant Construction: Built with marine-grade stainless steel housing, high-temp rubber seals, and a reinforced brass spring to withstand saltwater, extreme heat, and harsh engine environments.
Optimizes Engine Performance & Longevity: Maintains precise coolant flow to regulate engine temperature between the temperature rating, preventing overheating in summer and overcooling in winter. Enhances fuel efficiency and reduces engine wear.
Smart Thermal Control Mechanism: Features a fail-safe wax pellet design that automatically opens at 130°F / 54°C, to circulate coolant and closes when cooled, ensuring consistent thermal management for Mercury outboards.
Quick Installation: Includes pre-assembled thermostat and gasket. No drilling or modifications required—replaces old units directly using basic hand tools.