Water Shutter Kit – Fits MerCruiser V6/V8 Stern Drive Engines (Replaces 807166A1)
Water Shutter Kit – Fits MerCruiser V6/V8 Stern Drive Engines (Replaces 807166A1) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Water Shutter Kit – Fits MerCruiser V6/V8 Stern Drive Engines (Repl...
Product Details
This Water Shutter Kit – Fits MerCruiser V6/V8 Stern Drive Engines (Replaces 807166A1) is designed for MerCruiser stern drive engines from 1996 to the present that are equipped with a 4" exhaust system. The water shutters function as crucial check valves, preventing water from flowing back into the engine's exhaust manifolds when the engine is shut off or idling at low RPMs.
This kit provides a direct interchange for MerCruiser 807166A1, Sierra 18-2732, GLM 89170, and Mallory 9-42802. It includes all necessary components for a complete replacement of the water shutters and exhaust bellows in the Y-pipe.
- Installs in the exhaust Y-pipe to prevent water ingestion.
- Engineered for standard marine gasoline engine exhaust environments.
- Includes two shutters, two upper bellows, two lower bellows, and four stainless steel clamps.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| MerCruiser | 807166A1 |
| Sierra | 18-2732 |
| GLM | 89170 |
| Mallory | 9-42802 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This kit is compatible with a wide range of MerCruiser sterndrive and inboard engines. Please note the distinction for V6 engines with one-piece manifolds, which require a different part (807166A2).
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| MerCruiser | 4.3L (2 BBL.) GM 262 V-6 | Various | 4-Stroke | 1988–1992 | 807166A1 |
| MerCruiser | 4.3LX (4 BBL.) GM 262 V-6 | Various | 4-Stroke | 1988–1992 | 807166A1 |
| MerCruiser | 4.3L (GEN II) (2 BBL.) GM 262 V-6 | Various | 4-Stroke | 1992–1995 | 807166A1 |
| MerCruiser | 4.3LX (GEN II) (4 BBL.) GM 262 V-6 | Various | 4-Stroke | 1992–1995 | 807166A1 |
| MerCruiser | 5.0L (2 BBL.) GM 305 V-8 | Various | 4-Stroke | 1988–1995 | 807166A1 |
| MerCruiser | 5.0LX (4 BBL.) GM 305 V-8 | Various | 4-Stroke | 1988–1995 | 807166A1 |
| MerCruiser | 5.7L GM 350 V-8 | Various | 4-Stroke | 1988–1995 | 807166A1 |
| MerCruiser | 5.7L ALPHA EFI (TBI) GM 350 V-8 | Various | 4-Stroke | 1995 | 807166A1 |
| MerCruiser | 5.7L BRAVO EFI (TBI) GM 350 V-8 | Various | 4-Stroke | 1995 | 807166A1 |
| MerCruiser | 7.4L BRAVO GM 454 V-8 | Various | 4-Stroke | 1988–1991 | 807166A1 |
| MerCruiser | 7.4L BRAVO (GEN. V) GM 454 V-8 | Various | 4-Stroke | 1992–1994 | 807166A1 |
| MerCruiser | 454 MAG. BRAVO (GEN. V) GM 454 V-8 | Various | 4-Stroke | 1992–1994 | 807166A1 |
| MerCruiser | 454 MAG. BRAVO MPI GM 350 V-8 | Various | 4-Stroke | 1995 | 807166A1 |
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | D3.0L VM 183 I/L5 | Various | 4-Stroke | 1994–1995 | 807166A1 | Diesel |
| MerCruiser | D3.6L VM 219 I/L6 | Various | 4-Stroke | 1994–1995 | 807166A1 | Diesel |
| MerCruiser | D4.2L/220 IDI VM 254 I/L6 | Various | 4-Stroke | 1994–1995 | 807166A1 | Diesel |
| MerCruiser | D183 TURBO AC VM 183 I/L5 | Various | 4-Stroke | 1990–1993 | 807166A1 | Diesel |
| MerCruiser | D219 TURBO AC VM 219 I/L6 | Various | 4-Stroke | 1990–1993 | 807166A1 | Diesel |
| MerCruiser | D254 TURBO AC VM 254 I/L6 | Various | 4-Stroke | 1990–1993 | 807166A1 | Diesel |
| MerCruiser | 530 D-TA VM 183 I/L5 | Various | 4-Stroke | 1989 | 807166A1 | Diesel |
| MerCruiser | 636 D-TA VM 219 I/L6 | Various | 4-Stroke | 1989 | 807166A1 | Diesel |
Technical Specs
- Product Type
- Exhaust Water Shutter Kit
- Installation
- Exhaust Y-Pipe
- Fuel Type
- Gasoline
- Connection
- 4" Exhaust System
- Housing Material
- Rubber/Neoprene
- Housing Color
- Black
- Dimensions
- Approximately 4" diameter (101.6 mm)
- Working Pressure
- Standard exhaust back pressure
- Operating Temperature
- Up to 105°C (221°F)
- Warranty
- 1 Year (Aftermarket)
- Other Technical Attributes
- 2-piece "clapper" design; prevents water backflow
What’s in the Box
- 2 x Water Shutters/Flappers (807166A1)
- 2 x Lower Exhaust Bellows (32-14358T/32-14358001)
- 2 x Upper Exhaust Bellows (32-44348T/32-44348001)
- 4 x Stainless Clamps
Installation Notes
- Disconnect the battery for safety before beginning any work on the engine or drive system.
- Gain access to the exhaust Y-pipe, which may require removing the stern drive unit.
- Carefully remove the old exhaust bellows and clamps to access the water shutters inside the Y-pipe.
- Inspect the Y-pipe for any damage or debris and clean the sealing surfaces thoroughly.
- Insert the new water shutters, ensuring they are oriented correctly to open with exhaust flow and close against backflow.
- Install the new lower and upper exhaust bellows using the provided stainless steel clamps.
- Ensure all clamps are tightened securely to prevent exhaust and water leaks.
- Reassemble any components that were removed to gain access.
- After reassembly, run the engine and check for any signs of exhaust or water leaks around the new components.
Troubleshooting & FAQ
How do I know if this kit will fit my engine?
This kit is specifically designed for MerCruiser V6 and V8 engines with a 4-inch diameter exhaust system, generally from 1996 to the present. The most important factor is the 4" exhaust size. Please note, it will not work on V6 engines that have a one-piece exhaust manifold; those typically require part number 807166A2. Always cross-reference the part numbers in our matrix and check your engine model against the compatibility list.
What are the signs of a failing water shutter?
Common symptoms of failed or missing water shutters include water ingestion into the engine cylinders, which can lead to hydrolock, a catastrophic engine failure. You might also experience difficulty starting, a gurgling sound from the exhaust, or finding water in the exhaust manifolds upon inspection.
How often should I replace my water shutters?
Water shutters are a wear item and should be inspected as part of your regular exhaust system maintenance schedule. While there is no fixed interval, it is common to replace them every 3-5 years or whenever the exhaust bellows are being replaced, as they are located in the same assembly.
Why is it important to prevent water backflow?
When an engine is shut down, cooling water in the exhaust system can flow backward into the exhaust manifolds and potentially enter the engine cylinders through open exhaust valves. This can cause severe internal corrosion and, in a worst-case scenario, hydrolock, which can bend connecting rods and destroy the engine upon the next startup attempt.
Can I buy and install just the shutters without the bellows?
This is sold as a complete kit because the bellows often must be removed to access the shutters. It is best practice to replace the bellows at the same time, as they are exposed to the same harsh conditions and are likely near the end of their service life if the shutters have failed.
What's the difference between OEM and aftermarket parts?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
What are your shipping speed and cost?
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
What is the warranty and return policy?
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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