Flat Washer – Fits Mercury Marine/Mercruiser (Replaces 12-39116)
Flat Washer – Fits Mercury Marine/Mercruiser (Replaces 12-39116) 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).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Flat Washer – Fits Mercury Marine/Mercruiser (Replaces 12-39116)
Product Details
This stainless steel Flat Washer is a direct replacement part for Mercury Marine/Mercruiser sterndrive and transom assemblies manufactured from 1966 to the present. It is used in various series, including Alpha One, R/MR, and Vazer.
This component directly interchanges with Mercury Marine part number 12-39116 and Quicksilver part number 12-39116.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury Marine | 12-39116 |
| Quicksilver | 12-39116 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This part fits a wide array of Mercruiser engines. Please check your engine's serial number against the ranges provided to ensure an exact fit.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercruiser | 120/140 | 120-140 | 1967–1982 | 12-39116 | Used in serial ranges 2062141-6225576 | |
| Mercruiser | 160/165 | 160-165 | 1967–1981 | 12-39116 | Used in serial ranges 2065190-4890459 & Up | |
| Mercruiser | 225-S | 225 | 1974 | 12-39116 | Used in serial ranges 3856268-4200499 | |
| Mercruiser | 228 | 228 | 1978–1982 | 12-39116 | Used in serial ranges 4898730-6225576 | |
| Mercruiser | 233 | 233 | 1975–1977 | 12-39116 | Used in serial ranges 4200500 & Up | |
| Mercruiser | 250 | 250 | 1977 | 12-39116 | Used in serial ranges 4791300-4898729 | |
| Mercruiser | 260 | 260 | 1978–1982 | 12-39116 | Used in serial ranges 4898730-6225576 | |
| Mercruiser | 470 | 470 | 1976–1982 | 12-39116 | Used in serial ranges 4208730-6225576 | |
| Mercruiser | 485 | 485 | 1980–1982 | 12-39116 | Used in serial ranges 4893835 & Up | |
| Mercruiser | 888 | 1971–1977 | 12-39116 | Used in serial ranges 3106717 & Up | ||
| Mercruiser | 898 | 1978–1982 | 12-39116 | Used in serial ranges 4898730-6225576 | ||
| Mercruiser | 898/228 | 1977 | 12-39116 | Used in serial ranges 4782330-4898729 | ||
| Mercruiser | ALPHA ONE (GEN. II) | 1991–Present | 12-39116 | Used in serial ranges 0D469859 & Up | ||
| Mercruiser | R/MR/ALPHA ONE (Sterndrive) | 1983–1990 | 12-39116 | Used in serial ranges 6225577-0F386995 | ||
| Mercruiser | R/MR/ALPHA ONE (Transom Assembly) | 1983–1990 | 12-39116 | Used in serial ranges 6216687-0F386995 | ||
| Mercruiser | 80 (Sterndrive) | 80 | 1966–1969 | 12-39116 | Used in serial ranges 2063741-2898029 | |
| Mercruiser | 80 RENAULT 80 I/L4 | 80 | 4-Stroke | 1966–1969 | 12-39116 | Used in serial ranges 2049045-2851423 |
| Mercruiser | 90 (Sterndrive) | 90 | 1970–1972 | 12-39116 | Used in serial ranges 2898020-3225967 | |
| Mercruiser | 90 RENAULT 96 I/L4 | 96 | 4-Stroke | 1970–1972 | 12-39116 | Used in serial ranges 2851424-3226957 |
| Mercruiser | VAZER DRIVE | 12-39116 | Used in serial ranges 0W995000 & Up | |||
| Mercruiser | VAZER TRANSOM | 12-39116 | Used in serial ranges 0W755000 & Up |
Technical Specs
- Product Type
- Flat Washer
- Material
- Stainless Steel
- Product Dimensions
- 8.5 in × 10.0 in × 0.1 in
- Weight
- 4.96 oz (140.6 g)
- Brand
- Mercury Marine/Quicksilver
- Manufacturer Part Number
- 12-39116
- UPC
- 745061141025
- Other Technical Attributes
- OEM (Original Engine Manufacturer) part
What’s in the Box
- 1 x WASHER (12-39116)
Installation Notes
- Safety First: Disconnect the battery and ensure the engine is cool before beginning work.
- Access the Component: Locate the assembly (e.g., sterndrive, transom) where the washer is. This may require removing other parts.
- Remove Old Hardware: Carefully remove the fastener and the worn or damaged washer.
- Clean the Surface: Clean all mating surfaces to ensure they are free of debris, corrosion, and old sealant.
- Install the New Washer: Place the new 12-39116 flat washer in the correct position.
- Reassemble & Torque: Re-install the fastener and torque it to the manufacturer's specified value. Do not overtighten.
- Final Check: Once assembled, reconnect power, run the engine, and check thoroughly for any leaks or unusual vibrations.
Troubleshooting & FAQ
How do I confirm this washer fits my engine?
The best way to confirm fitment is to match your engine's model, year, and serial number against our compatibility chart. This part is a direct replacement for OEM part number 12-39116. If your service manual specifies this part number, it will fit.
What are the signs of a failing washer?
Signs of a worn or failing washer include fluid leaks around the seal, visible corrosion, or loose fittings that cannot be tightened. During routine maintenance, any washer that appears overly compressed or damaged should be replaced.
Can I reuse my old washer?
We do not recommend reusing washers, especially in sealing applications. They are typically single-use components that compress and deform to create a seal. Reusing one may result in leaks or improper fastening.
Are the product dimensions correct?
The washer is manufactured to the precise inner diameter, outer diameter, and thickness specifications for OEM part 12-39116. The dimensions listed in our specs (8.5 in × 10.0 in × 0.1 in) refer to the shipping package, not the washer itself.
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
Payment methods
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