Water Shutter Kit – Fits MerCruiser V6/V8 Stern Drives (Replaces 807166A3)
Water Shutter Kit – Fits MerCruiser V6/V8 Stern Drives (Replaces 807166A3) 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.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
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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 Drives (Replaces 80...
Product Details
This aftermarket Water Shutter Kit – Fits MerCruiser V6/V8 Stern Drives (Replaces 807166A3) is designed for MerCruiser stern drive engines equipped with 4-inch exhaust systems, primarily covering V6 and V8 models manufactured from 1982 through 1996. It serves the critical function of preventing water from flowing back into the engine through the exhaust, protecting internal components from corrosion and damage.
This kit is a direct interchange for several part numbers, including Mercury/MerCruiser 807166A3 and 807166A1, Sierra 18-2732-9, GLM 89170, and Mallory 9-42802.
- Installs directly into the exhaust Y-Pipe.
- Features a robust 2-piece "clapper" design to effectively block water backflow.
- Engineered with durable rubber/neoprene for longevity in marine environments.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury/MerCruiser | 807166A3 |
| Mercury/MerCruiser | 807166A1 |
| Sierra | 18-2732-9 |
| GLM | 89170 |
| Mallory | 9-42802 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This part is designed for the following MerCruiser Sterndrive and Inboard models.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 4.3L (2 BBL.) GM 262 V-6 | Various | 4-Stroke | 1988–1992 | 807166A3 | |
| MerCruiser | 4.3LX (4 BBL.) GM 262 V-6 | Various | 4-Stroke | 1988–1992 | 807166A3 | |
| MerCruiser | 4.3L (GEN II) (2 BBL.) GM 262 V-6 | Various | 4-Stroke | 1992–1995 | 807166A3 | |
| MerCruiser | 4.3LX (GEN II) (4 BBL.) GM 262 V-6 | Various | 4-Stroke | 1992–1995 | 807166A3 | |
| MerCruiser | 5.0L (2 BBL.) GM 305 V-8 | Various | 4-Stroke | 1988–1995 | 807166A3 | |
| MerCruiser | 5.0LX (4 BBL.) GM 305 V-8 | Various | 4-Stroke | 1988–1995 | 807166A3 | |
| MerCruiser | 5.7L GM 350 V-8 | Various | 4-Stroke | 1988–1995 | 807166A3 | |
| MerCruiser | 5.7L ALPHA EFI (TBI) GM 350 V-8 | Various | 4-Stroke | 1995 | 807166A3 | |
| MerCruiser | 5.7L BRAVO EFI (TBI) GM 350 V-8 | Various | 4-Stroke | 1995 | 807166A3 | |
| MerCruiser | 7.4L BRAVO GM 454 V-8 | Various | 4-Stroke | 1988–1991 | 807166A3 | |
| MerCruiser | 7.4L BRAVO (GEN. V) GM 454 V-8 | Various | 4-Stroke | 1992–1994 | 807166A3 | |
| MerCruiser | 454 MAG. BRAVO (GEN. V) GM 454 V-8 | Various | 4-Stroke | 1992–1994 | 807166A3 | |
| MerCruiser | 454 MAG. BRAVO MPI GM 350 V-8 | Various | 4-Stroke | 1995 | 807166A3 | |
| MerCruiser | D3.0L VM 183 I/L5 | Various | 4-Stroke | 1994–1995 | 807166A3 | Diesel |
| MerCruiser | D3.6L VM 219 I/L6 | Various | 4-Stroke | 1994–1995 | 807166A3 | Diesel |
| MerCruiser | D4.2L/220 IDI VM 254 I/L6 | Various | 4-Stroke | 1994–1995 | 807166A3 | Diesel |
| MerCruiser | D183 TURBO AC VM 183 I/L5 | Various | 4-Stroke | 1990–1993 | 807166A3 | Diesel |
| MerCruiser | D219 TURBO AC VM 219 I/L6 | Various | 4-Stroke | 1990–1993 | 807166A3 | Diesel |
| MerCruiser | D254 TURBO AC VM 254 I/L6 | Various | 4-Stroke | 1990–1993 | 807166A3 | Diesel |
| MerCruiser | 530 D-TA VM 183 I/L5 | Various | 4-Stroke | 1989 | 807166A3 | Diesel |
| MerCruiser | 636 D-TA VM 219 I/L6 | Various | 4-Stroke | 1989 | 807166A3 | Diesel |
Technical Specs
- Product Type
- Exhaust Water Shutter Kit
- Installation
- Exhaust Y-Pipe
- Fuel Type
- Gasoline
- Connection
- 4-inch Exhaust System
- Housing Material
- Rubber/Neoprene
- Housing Color
- Black
- Dimensions
- Approx. 4 inches diameter (101.6 mm)
- 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 (Replaces 807166A3)
- 2 x Lower Exhaust Bellows (Replaces 32-14358T/32-14358001)
- 2 x Upper Exhaust Bellows (Replaces 32-44348T/32-44348001)
- 4 x Stainless Steel Clamps
Installation Notes
IMPORTANT: This kit is not compatible with V6 engines that have a one-piece exhaust manifold (which require part 807166A2) or early model V8 engines that use a round pin passing through the flapper. Always verify your existing part design before ordering.
- Ensure the engine is off and cool. Disconnect the boat's battery for safety.
- Gain access to the exhaust Y-pipe where the water shutters are located.
- Carefully remove the old, deteriorated exhaust bellows and water shutters. Note their orientation.
- Thoroughly clean the surfaces of the Y-pipe and exhaust tube, removing any old sealant or debris.
- Install the new water shutters, ensuring they are oriented correctly to prevent water backflow.
- Fit the new upper and lower exhaust bellows into position.
- Securely fasten the bellows using the provided stainless steel clamps. Ensure a tight seal.
- Reconnect the battery. Start the engine and check for any exhaust or water leaks around the new components.
Troubleshooting & FAQ
How do I know if this water shutter kit fits my engine?
This kit is specifically for MerCruiser V6/V8 engines (primarily 1982–1996) with a 4-inch exhaust system. It is critical to note that it will not fit V6 engines with a one-piece manifold or older V8 models using a round-pin flapper design. Compare your existing parts with our images and check the compatibility list.
What are the signs of a failed water shutter?
Common symptoms of failure include a rattling or clanking sound from the exhaust area at idle, difficulty starting, or, in severe cases, water entering the engine cylinders (hydrolock), which can cause catastrophic damage. Visual inspection may also reveal cracked, broken, or missing shutter flaps.
How often should these parts be replaced?
We recommend inspecting water shutters and exhaust bellows annually as part of routine maintenance. For boats used in saltwater, replacement is recommended every 2–3 years. For freshwater use, a 3–5 year interval is typical, or sooner if signs of wear like stiffness or cracking are visible.
Is it difficult to replace these parts myself?
For individuals with mechanical experience, the replacement is a manageable task. However, access to the Y-pipe can be restricted, and ensuring a proper seal is critical. If you are not comfortable performing the work, we strongly recommend professional installation to prevent leaks and potential engine damage.
someOEM vs. Aftermarket?
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.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
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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