Drain Plug Gasket – Fits Mercury/Mercruiser Engines (Replaces 27-49955/8M0077608)
Drain Plug Gasket – Fits Mercury/Mercruiser Engines (Replaces 27-49955/8M0077608) 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
Product Details
This is an aftermarket Drain Plug Gasket for a wide range of Mercury and Mercruiser engines from 120HP to 700HP, spanning multiple decades of production. It is designed for use on oil pans, gear cases, and similar drain plug applications, ensuring a secure seal to prevent leaks.
This part provides a direct replacement for Mercury/Quicksilver 27-49955/8M0077608, Sierra 18-0905, and Generic 584-150.
- Installs on oil pan, gear case, and other drain plugs
- Engineered for marine engine environments
- Prevents oil and gear lube leaks
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Superseded By |
|---|---|---|
| Mercury | 27-49955 | 8M0077608 |
| Quicksilver | 27-49955 | 8M0077608 |
| Sierra | 18-0905 | |
| Generic | 584-150 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This gasket has extremely broad compatibility across nearly all Mercruiser engines, as well as select Mercury models. The following is a condensed list of major compatible engine families.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercruiser | 120 GM 153 I/L4 | 120 | 4-Stroke | 1964–1986 | 27-49955/8M0077608 | All serial ranges |
| Mercruiser | 140 GM 181 I/L4 | 140 | 4-Stroke | 1968–1986 | 27-49955/8M0077608 | All serial ranges |
| Mercruiser | 2.5L GM 153 I/L4 | 120 | 4-Stroke | 1987–1989 | 27-49955/8M0077608 | |
| Mercruiser | 3.0L GM 181 I/L4 | 130-140 | 4-Stroke | 1987–Present | 27-49955/8M0077608 | All serial ranges |
| Mercruiser | 160-165 GM 250 I/L6 | 160-165 | 4-Stroke | 1967–1981 | 27-49955/8M0077608 | All serial ranges |
| Mercruiser | 200 GM 292 I/L6 | 200 | 4-Stroke | 1969 | 27-49955/8M0077608 | |
| Mercruiser | V6 Models (175, 185, 205, 262 MAG) | 175-205 | 4-Stroke | 1983–1997 | 27-49955/8M0077608 | Includes 4.3L models |
| Mercruiser | V8 Models (198-898) | 198-898 | 4-Stroke | 1977–1987 | 27-49955/8M0077608 | Includes 305, 350, 454 variants |
| Mercruiser | 5.0L/5.7L | 220-330 | 4-Stroke | 1988–Present | 27-49955/8M0077608 | Multiple serial ranges |
| Mercruiser | 7.4L/8.1L | 310-425 | 4-Stroke | 1988–Present | 27-49955/8M0077608 | Multiple models and configurations |
| Mercruiser | 496 MAG Models | 375-425 | 4-Stroke | 1999–Present | 27-49955/8M0077608 | Base and H.O. models |
| Mercruiser | 500/525/565/600/662/700 Models | 500-700 | 4-Stroke | 1990–Present | 27-49955/8M0077608 | EFI, SC and SCi variants |
| Mercruiser | Black Scorpion / MX 6.2L | 320-425 | 4-Stroke | 1996–2002 | 27-49955/8M0077608 | |
| Mercruiser | 8.2L V8 Models | 380-430 | 4-Stroke | 1993–2000 | 27-49955/8M0077608 | |
| Mercury | Vazer 100 | 100 | 4-Stroke | 27-49955/8M0077608 |
Technical Specs
- Product Type
- Drain Plug Gasket
- Application
- Marine engine oil/gear drain plugs
- Material
- Copper
- Shape
- Round/Washer
- Product Dimensions
- 4.0 x 5.13 x 0.25 inches
- Weight
- 1 lb (0.45 kg)
- Package Quantity
- 1
- OEM Manufacturer
- Quicksilver - Mercruiser
What’s in the Box
- 1 x Gasket, Drain Screw (27-49955/8M0077608)
Installation Notes
- Position a drain pan under the engine oil or gear case drain plug.
- Loosen and remove the drain plug, allowing the old fluid to drain completely.
- Remove the old gasket from the drain plug or housing. Clean both the plug and the mating surface on the case, ensuring they are free of old gasket material, oil, and debris.
- Place the new gasket over the threads of the drain plug.
- Reinstall the drain plug with the new gasket and tighten it to the manufacturer's specified torque. Do not overtighten.
- Refill the engine or gear case with the correct type and amount of new fluid. Check for leaks around the drain plug.
Troubleshooting & FAQ
How do I know if this gasket fits my specific engine model?
This gasket has very broad compatibility. The best method is to consult your engine's service manual or parts catalog to confirm the OEM part number is 27-49955 or 8M0077608. The compatibility table above lists major engine families, but cross-referencing the part number is the most reliable way to ensure a correct fit.
What are the signs of a failing drain plug gasket?
The most common sign is a slow drip or seepage of oil or gear lube from around the drain plug. You may notice an oily film on the engine pan or lower unit, or spots of oil on the ground where the engine is stored. Replacing the gasket during your regular fluid changes is the best way to prevent this.
Is this gasket reusable?
No, drain plug gaskets are designed as single-use crush washers. Once torqued, they deform to create a seal. Reusing an old gasket significantly increases the risk of leaks. It is critical to use a new gasket every time you change your oil or gear lube.
How often should I replace this gasket?
The drain plug gasket should be replaced every time the drain plug is removed. This typically occurs during routine maintenance, such as annual oil changes or gear lube services.
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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