Water Shutter Kit – Fits MerCruiser 3.0-4.2L Sterndrive & Inboard (Replaces MerCruiser 807166A3, Sierra 18-2732-9)
Water Shutter Kit – Fits MerCruiser 3.0-4.2L Sterndrive & Inboard (Replaces MerCruiser 807166A3, Sierra 18-2732-9) 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 3.0-4.2L Sterndrive & Inboa...
Product Details
This Water Shutter Kit is an essential exhaust system component designed to prevent water from entering the engine. It is engineered for MerCruiser 3.0L to 4.2L inline sterndrive and inboard engines manufactured between approximately 1994 and 1997, including D3.0L VM 183 I/L5, D3.6L VM 219 I/L6, and D4.2L/220 IDI VM 254 I/L6 models.
The kit serves as a direct replacement for MerCruiser part 807166A3 and interchanges with Sierra 18-2732-9, GLM 89170, and Mallory 9-42802.
- Installs in the Y-pipe of the MerCruiser exhaust system.
- Built with durable materials for operation in harsh marine environments.
- Kit includes two water shutters for a complete replacement.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| MerCruiser | 807166A3 |
| MerCruiser | 14348 |
| MerCruiser | 14348A1 |
| MerCruiser | 14348A2 |
| Sierra | 18-2732-9 |
| GLM | 89170 |
| Mallory | 9-42802 |
| QuickMarine | 807166A3 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser Sterndrive Models:
| Model | Engine | Rated HP | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|
| D3.0L (BRAVO) | VM 183 I/L5 | 3.0L | 1994–1997 | 807166A3 | Serial #0D725152 THRU 0F999999 |
| D3.6L (BRAVO) | VM 219 I/L6 | 3.6L | 807166A3 | Serial #0D850128 THRU 99999999999999999 | |
| D4.2L/220 IDI | VM 254 I/L6 | 4.2L | 807166A3 | Serial #0D554732 THRU 0M999999 |
For MerCruiser Inboard Models:
| Model | Engine | Rated HP | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|
| D3.0L | VM 183 I/L5 | 3.0L | 1994–1995 | 807166A3 | Serial #0D725152 THRU 0F999999 |
| D3.6L | VM 219 I/L6 | 3.6L | 807166A3 | Serial #0D850128 THRU 99999999999999999 | |
| D4.2L/220 IDI | VM 254 I/L6 | 4.2L | 807166A3 | Serial #0D554732 THRU 0M999999 | |
| D183 TURBO AC | VM 183 I/L5 | 1990–1993 | 807166A3 | BRAVO & MIE | |
| D219 TURBO AC | VM 219 I/L6 | 1990–1993 | 807166A3 | BRAVO & MIE | |
| D254 TURBO AC | VM 254 I/L6 | 1990–1993 | 807166A3 | ||
| 530 D-TA | VM 183 I/L5 | 1989 | 807166A3 | BRAVO & MIE | |
| 636 D-TA | VM 219 I/L6 | 1989 | 807166A3 | BRAVO & MIE |
Technical Specs
- Product Type
- Exhaust Water Shutter Kit
- Installation
- Y-pipe of MerCruiser exhaust system
- Connection
- Direct fit into exhaust housing
- Housing Material
- Corrosion-resistant metal
- Housing Color
- Black
- Dimensions
- Length: 6.13" (155.7mm), Width: 2.36" (59.9mm)
- Weight
- 2.24 oz (63.5g)
- Fitting Type
- Direct replacement
- Other Technical Attributes
- Durable construction for operation in harsh marine environments
What’s in the Box
- 2 x Water Shutters (Replaces 807166A3)
Installation Notes
- Ensure the engine is off and completely cool. Disconnect the battery for safety.
- Locate the exhaust Y-pipe where the old water shutters are housed.
- Remove the components necessary to access the shutters, such as exhaust hoses or bellows.
- Extract the old, worn, or damaged water shutters. Clean any debris from the housing.
- Insert the new water shutters, ensuring they are correctly oriented and seated.
- Reassemble the exhaust components that were removed.
- Reconnect the battery. Start the engine and check for proper operation and any exhaust leaks.
Troubleshooting & FAQ
How do I know if this water shutter fits my engine?
This part is for specific MerCruiser inline engines from approximately 1989-1997. Please carefully check the compatibility table on this page, matching your model, year, and serial number range. Verifying against your old part's number (807166A3) is the best way to confirm fitment.
What are the signs of a failing water shutter?
Common symptoms include a rattling noise from the exhaust at idle, water ingestion into the engine (hydrolock), or visible damage/cracking on the shutter flaps. Replacement is recommended if you notice any of these signs.
How often should I inspect or replace my water shutters?
Water shutters should be inspected annually as part of regular exhaust system maintenance. Replacement intervals depend on usage (freshwater vs. saltwater) and operating conditions, but they should be replaced immediately if they show signs of wear, brittleness, or damage.
Can I replace just one shutter?
It is strongly recommended to replace both shutters at the same time, as they are exposed to the same conditions and wear at a similar rate. This kit includes a pair for a complete service.
What is the function of a water shutter?
A water shutter, or water flapper, is a one-way valve in the exhaust system that allows exhaust gases to exit while preventing water from flowing back into the engine, especially when the boat is decelerating or in reverse.
OEM 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.
Payment & Security
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