Water Shutter Flappers kit Bushings Replace Mercruiser Mercury V8 and V6 807166A1 525-807166A1 Engines 1998 and Newer … (1)

For Mercruiser Mercury Outboard Part Number: 807166A1, 525-807166A1 (IMPT: check OEM part number before purchase!!)
Water Shutter measures 2-1/2" wide X 6-1/8" long
Contents:1 Flapper and 2 Grommets
For 1998 and newer engines, there are some 1996 and 1997 models that apply. There will be two rectangular holes for the grommets. If your Y-pipe has round holes you need the A3 water shutters. If your Y-pipe changes size a few inches bellow the shutter you have a one piece manifold V6 Y-pipe and need shutter A2.
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.