Exhaust Manifold Gasket – Fits MerCruiser 3.7L 4-Cylinder Engines (Replaces 27-68715)
Exhaust Manifold Gasket – Fits MerCruiser 3.7L 4-Cylinder Engines (Replaces 27-68715) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Exhaust Manifold Gasket – Fits MerCruiser 3.7L 4-Cylinder Engines (...
Product Details
This high-quality Exhaust Manifold Gasket is engineered for a precise fit on Mercury MerCruiser 3.7L 4-cylinder engines from 1976 to 1989, including 165, 170, 180, 190 HP, 3.7L, 3.7LX, 470, 485, and 488 models. It is also designed to fit select OMC 460 and 754 model engines, providing a reliable seal to prevent exhaust leaks.
It serves as a direct replacement for multiple part numbers, offering a versatile interchange with references from Mercury Marine, Sierra, GLM, Mallory, OMC, and Chrysler.
- Installs between the exhaust manifold and the cylinder head.
- Constructed from durable composite gasket material to withstand high temperatures and pressure.
- Ensures a tight seal to maintain engine performance and efficiency.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket brands.
| Brand | Part Number |
|---|---|
| Mercury Marine | 27-68715 |
| Sierra | 18-0956-1 / 18-0992 |
| GLM | 31710 / 33800 |
| Mallory | 9-61418 |
| OMC | 912405 |
| Chrysler | 118-614 |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure accurate fitment.
The following table details compatibility for Mercury MerCruiser engines, including model years and corresponding serial number ranges.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 165 (2 BBL.) MERCURY 224 I/L4 | 165 | 4-Stroke | 1987 | 27-68715 | Serial: 0B434941 THRU 0B774251 |
| MerCruiser | 170 (2 BBL.) MERCURY 224 I/L4 | 170 | 4-Stroke | 1985–1986 | 27-68715 | Serial: 6916779 THRU 0B434940 |
| MerCruiser | 180 (4 BBL.) MERCURY 224 I/L4 | 180 | 4-Stroke | 1987 | 27-68715 | Serial: 0B436391 THRU 0B775248 |
| MerCruiser | 190 (4 BBL.) MERCURY 224 I/L4 | 190 | 4-Stroke | 1985–1986 | 27-68715 | Serial: 6916779 THRU 0B436390 |
| MerCruiser | 3.7L (2 BBL.) MERCURY 224 I/L4 | 165 | 4-Stroke | 1988–1989 | 27-68715 | Serial: 0B774252 & Up |
| MerCruiser | 3.7LX (4 BBL.) MERCURY 224 I/L4 | 180 | 4-Stroke | 1988–1989 | 27-68715 | Serial: 0B775249 & Up |
| MerCruiser | 470 (2 BBL.) MERCURY 224 I/L4 | 170 | 4-Stroke | 1976–1979 | 27-68715 | Serial: 4208730 THRU 5520114 |
| MerCruiser | 470 (2 BBL.) MERCURY 224 I/L4 | 170 | 4-Stroke | 1980–1982 | 27-68715 | Serial: 5520115 THRU 6218036 |
| MerCruiser | 470 (2 BBL.) MERCURY 224 I/L4 | 170 | 4-Stroke | 1983–1984 | 27-68715 | Serial: 6218037 THRU 6916778 |
| MerCruiser | 470 MIE MERCURY 224 I/L4 | 170 | 4-Stroke | 1980–1981 | 27-68715 | Serial: 5520115 THRU 6218036 |
| MerCruiser | 485 (2 BBL.) MERCURY 224 I/L4 | 185 | 4-Stroke | 1980–1982 | 27-68715 | Serial: 5685394 THRU 6218036 |
| MerCruiser | 488 (4 BBL.) MERCURY 224 I/L4 | 185 | 4-Stroke | 1983–1984 | 27-68715 | Serial: 6170297 THRU 6916778 |
Technical Specs
- Product Type
- Exhaust Manifold Gasket
- Installation
- Between exhaust manifold and cylinder head
- Material
- Composite gasket material
- Dimensions
- 48.0 x 9.5 x 0.2 cm (approx. 18.9 x 3.74 x 0.08 inches)
- Weight
- 0.142 kg (5 ounces)
- OEM Reference
- Mercury Marine 27-68715
- Application
- Marine 4-cylinder engines
What’s in the Box
- 1 x Exhaust Manifold Gasket (27-68715)
Installation Notes
- Disconnect the boat's battery and drain the engine coolant from the manifold.
- Carefully unbolt and remove the exhaust manifold from the cylinder head.
- Remove the old gasket and thoroughly clean any residue from both mating surfaces.
- Position the new gasket, ensuring it aligns correctly with all ports and bolt holes.
- Reinstall the manifold and tighten the bolts to the manufacturer's recommended torque specifications and sequence.
- Refill the cooling system with the appropriate coolant.
- Reconnect the battery, start the engine, and carefully check for any exhaust or fluid leaks around the manifold.
Troubleshooting & FAQ
How do I confirm this gasket will fit my engine?
This gasket fits a range of MerCruiser 3.7L 4-cylinder engines (1976–1989) and select OMC models. To ensure a perfect match, check the "Engine & Model Compatibility" table and verify your engine's serial number is within the specified range. Cross-referencing your old part number with our "Part Number Matrix" is also a reliable confirmation method.
What are the signs of a failing exhaust manifold gasket?
Common symptoms include a ticking or hissing sound from the engine (especially when cold), reduced engine performance, higher operating temperatures, or visible soot/black streaks around the manifold-head joint. You may also notice a strong exhaust smell in the engine bay or bilge.
How does this aftermarket gasket compare to the OEM part?
This is an aftermarket component engineered to meet or exceed OEM specifications. It is made from a comparable high-quality composite material to ensure a durable, long-lasting seal. It offers a cost-effective solution without compromising on quality or performance.
Should I use sealant with this gasket?
This type of composite gasket is typically designed to be installed dry. Applying sealants can sometimes interfere with its ability to seal correctly. Always consult your engine's service manual for the specific procedure and recommendations for your model.
Can I reuse the original manifold bolts?
It is strongly recommended to use new bolts, particularly if the old ones show any signs of corrosion, rust, or stretching. Manifold bolts endure extreme heat cycles and can lose their tensile strength. Always tighten to the manufacturer's specified torque in the correct sequence.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, all parts are batch-inspected for consistency and quality.
Shipping speed & cost
We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free, and expedited options will appear at checkout where available.
Warranty & returns
This product is covered by a 1-year warranty against manufacturing defects under normal use. If any issues arise, contact our support team with your order details. Returns are accepted within our standard window for unused items in their original condition. See our policy page or reach out for instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchasing. If anything differs—even if your model is listed as compatible—do not install.
- This is a high-quality aftermarket replacement component, not an OEM part.
- Professional installation is recommended for safety, performance, and to prevent damage to your engine.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world conditions.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with typical transit times of 5–15 days.
- Manufacturer-Direct Value — Our direct-sourcing model ensures fair pricing without compromising on materials or quality control.
Payment & Security
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