StayCoolPumps Water Shutter Replaces Mercruiser 807166A1

Used on many Mercruiser stern drive V8 engines. (Some V6 that came with the two piece maniflold/elbow) Note: These will Not work on V6 engines that came with the one piece manifolds (use 807166A2  it has a flat tip) ,or early V8 with the pin going through flapper. If you have ever overheated these tend to get damaged. Sometimes you will find pieces of them in the exhaust when you remove the drive for servicing. They help keep water from entering the engine through the exhaust.