OEM Mercury / Quicksilver 807166A3 Water Shutter

Water shutter 807166A3 is for use on various and numerous MerCruiser sterndrive installations. This shutter is 2.5 in. diameter at the cross pin. Check your owner's manual or parts manual for exact fitment. Also known as a water flapper, the shutter is open for exhaust to exit the engine and closes when the engine is not running to keep water from flowing back to the engine causing corrosion or serious damage to the engine. Fits inline inside the exhaust system for sterndrive installations. Installed downstream of the flexible union between the elbow and Y-pipe. See your owner's manual or service manual for specific application and instructions.