Sierra 18-2732-9 MerCruiser Exhaust Water Shutter 2-Pack

The Sierra 18-2732-9 water shutters act as one-way valves that prevent water from traveling backwards into the exhaust risers, manifolds, or engine cylinders. When the engine is not running, these flappers spring open to block following seas or waves from entering the exhaust system. This bell-type water shutter is constructed of rubber and steel materials and measures 6.125 inches in height by 2.360 inches long.

Key Features:

• Includes two water shutters per package
• Fits 4-inch exhaust for Mercury Marine MC-1/R/MR/Alpha One, Alpha Gen II and Bravo stern drives
• Pin included with each shutter
• Meets or exceeds original equipment specifications
• Engineered to match OEM shutters on MerCruiser installations

Water shutters are exposed to repeated heat cycling and saltwater abuse that can speed up the corrosion process and cause failure, making routine inspection and replacement strongly advised to protect your engine. This part is interchangeable with Mallory 9-42802, GLM 89170, and MerCruiser Stern Drive 14348, 14348A1, 14348A2, and 807166A3.