Outdrive Exhaust Water Shutter

This is a replacement for original flat oval plate with a round pin that is offset in the Y-pipe. It does not fit older, round Y-pipes.
Replaces:
Mercruiser 1438A1, 14348, 14348A2, 807166A3
Mallory 9-42802
GLM 89170
Pro Marine 65166
Redline 89170

Many exhaust installations include shutters (flappers), at the top of the exhaust "Y" pipe where each leg joins the rubber exhaust elbow leading to the exhaust riser. The water shutters act as one-way valves to prevent water from traveling backwards into the exhaust risers, manifolds, or even the engine cylinders.
When the engine is not running, the flapper springs open, blocking following seas or beach waves from entering the exhaust system. (Some designs are simpler asymmetric flappers.)
When the engine is running, the flow of exhaust pushes the shutter open.

Water shutters are exposed to repeated heat cycling and saltwater abuse that can speed up the corrosion process and cause failure; routine inspection and replacement is strongly advised to protect your expensive engine.
Sierra has engineered these water shutters to match the OEM shutters on many MerCruiser installations and protect water from traveling back into the engine via the exhaust system.

• Engineered to meet or exceed manufacturer specifications
• Protects sensitive engine components from being damaged by water traveling back through exhaust system
• Fits all MerCruiser #1 drives
• Backed by SeaStar Solutions limited two-year warranty
• V6 and V8 applications require 2 shutters