Mercury - Quicksilver Thermostat Kit Cooling System Component V6 135-200HP Outboards 75692Q2. Overview. Your outboard runs best when it's kept at just the right temperature. The Mercury Marine 75692Q2 Quicksilver Thermostat Kit helps maintain that balance, keeping your Mercury and Mariner V6 135-200HP outboards running cool, efficient, and dependable. Designed for select serial ranges, this OEM kit includes two thermostats and two rubber gaskets for a complete replacement. Each thermostat is bui