Aftermarket Exhaust Manifold Gasket for MerCruiser 3.7L 4-Cylinder Engines – OEM Reference 27-68715
Aftermarket Exhaust Manifold Gasket for MerCruiser 3.7L 4-Cylinder Engines – OEM Reference 27-68715 is backordered and will ship as soon as it is back in stock.
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Aftermarket Exhaust Manifold Gasket for MerCruiser 3.7L 4-Cylinder ...
Aftermarket Exhaust Manifold Gasket for MerCruiser 3.7L 4-Cylinder Engines – OEM Reference 27-68715 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket Exhaust Manifold Gasket is designed for the joint between the exhaust manifold and cylinder head on selected Mercury MerCruiser 3.7L, 224 CID, 4-cylinder engines. It is associated with the Mercury Marine OEM reference 27-68715 and is intended to help restore a reliable seal at the manifold-to-cylinder-head connection.
Catalog references identify this application with MerCruiser-built 4-cylinder 224 CID (3.7L) engines. The gasket is also cross-referenced in aftermarket catalogs as Sierra 18-0956-1, OMC 912405, Chrysler Inboard 118-614, and GLM 31710. Cross-reference numbers are provided for identification only; confirm the engine model, serial number, gasket shape, and port layout before ordering.
- Installs between the exhaust manifold and cylinder head.
- Provides a replacement sealing surface for a worn, damaged, or leaking manifold gasket.
- Helps prevent exhaust leaks when the mating surfaces, fasteners, and installation procedure are correct.
- Aftermarket replacement component; not manufactured by Mercury Marine.
Part Number Matrix
The following references are documented catalog cross-references for this gasket application. They are not a guarantee of fit for every engine carrying the same general model description.
| Brand or Source | Reference | Relationship |
|---|---|---|
| Mercury Marine | 27-68715 | OEM reference |
| Sierra | 18-0956-1 | Aftermarket replacement reference |
| OMC | 912405 | Catalog cross-reference |
| Chrysler Inboard | 118-614 | Catalog cross-reference |
| GLM | 31710 | Catalog reference; GLM catalog notes this gasket as not sold separately |
Engine & Model Compatibility
Use the model, year, and serial-number conditions together when checking fitment. The following application references are associated with the MerCruiser 224 CID (3.7L) 4-cylinder family.
| Brand | Model | Rated HP | Stroke | Years | OEM Reference | Serial Condition |
|---|---|---|---|---|---|---|
| MerCruiser | 165, 2 BBL., Mercury 224 I/L4 | 165 | 4-Stroke | 1987 | 27-68715 | 0B434941 through 0B774251 |
| MerCruiser | 170, 2 BBL., Mercury 224 I/L4 | 170 | 4-Stroke | 1985–1986 | 27-68715 | 6916779 through 0B434940 |
| MerCruiser | 180, 4 BBL., Mercury 224 I/L4 | 180 | 4-Stroke | 1987 | 27-68715 | 0B436391 through 0B775248 |
| MerCruiser | 190, 4 BBL., Mercury 224 I/L4 | 190 | 4-Stroke | 1985–1986 | 27-68715 | 6916779 through 0B436390 |
| MerCruiser | 3.7L, 2 BBL., Mercury 224 I/L4 | 165 | 4-Stroke | 1988–1989 | 27-68715 | 0B774252 and up |
| MerCruiser | 3.7LX, 4 BBL., Mercury 224 I/L4 | 180 | 4-Stroke | 1988–1989 | 27-68715 | 0B775249 and up |
| MerCruiser | 470, 2 BBL., Mercury 224 I/L4 | 170 | 4-Stroke | 1976–1979 | 27-68715 | 4208730 through 5520114 |
| MerCruiser | 470, 2 BBL., Mercury 224 I/L4 | 170 | 4-Stroke | 1980–1982 | 27-68715 | 5520115 through 6218036 |
| MerCruiser | 470, 2 BBL., Mercury 224 I/L4 | 170 | 4-Stroke | 1983–1984 | 27-68715 | 6218037 through 6916778 |
| MerCruiser | 470 MIE, Mercury 224 I/L4 | 170 | 4-Stroke | 1980–1981 | 27-68715 | 5520115 through 6218036 |
| MerCruiser | 485, 2 BBL., Mercury 224 I/L4 | 185 | 4-Stroke | 1980–1982 | 27-68715 | 5685394 through 6218036 |
| MerCruiser | 488, 4 BBL., Mercury 224 I/L4 | 185 | 4-Stroke | 1983–1984 | 27-68715 | 6170297 through 6916778 |
Technical Specifications
- Product Type
- Exhaust manifold gasket
- Application
- MerCruiser 224 CID (3.7L) 4-cylinder engines
- Installation Location
- Between the exhaust manifold and cylinder head
- Construction
- Composite gasket material
- Approximate Dimensions
- 48.0 x 9.5 x 0.2 cm (approximately 18.9 x 3.74 x 0.08 inches)
- Approximate Weight
- 0.142 kg (approximately 5 ounces)
- OEM Reference
- Mercury Marine 27-68715
What's in the Box
- 1 x Exhaust Manifold Gasket
Installation Notes
- Disconnect the battery and allow the engine to cool completely before beginning work.
- Drain coolant as required by the service procedure for the engine and manifold configuration.
- Remove the exhaust manifold and retain the fasteners in order if they will be reused.
- Remove the old gasket and clean both mating surfaces thoroughly. Do not damage the manifold or cylinder-head sealing surfaces.
- Position the replacement gasket so that all ports and bolt holes are correctly aligned.
- Reinstall the manifold and tighten the fasteners in the manufacturer's specified sequence and to the specified torque.
- Refill the cooling system with the correct coolant, reconnect the battery, and inspect for exhaust, coolant, or other leaks after starting the engine.
Troubleshooting & FAQ
How do I confirm that this gasket fits my engine?
Compare your engine's exact model, horsepower, stroke, year, and serial number with the compatibility table. Also compare the old gasket's outline, bolt-hole pattern, and exhaust-port openings. The OEM reference 27-68715 and documented cross-references can help identify the application, but they should not replace a complete fitment check.
What are common symptoms of a failed exhaust manifold gasket?
Possible symptoms include ticking or hissing near the manifold, visible soot at the manifold-to-head joint, an exhaust odor in the engine compartment, reduced performance, or abnormal operating temperature. These symptoms can also have other causes and should be diagnosed before replacement.
Is this an OEM Mercury Marine gasket?
No. This listing is for an aftermarket replacement gasket. Mercury Marine 27-68715 is provided as the OEM application reference, not as a statement that the replacement is manufactured by Mercury Marine.
Should sealant be used?
Do not apply sealant unless the engine service manual or gasket manufacturer specifically requires it. Many composite manifold gaskets are installed dry. Follow the procedure and torque specifications for the exact engine.
Can I reuse the manifold bolts?
Inspect all fasteners for corrosion, damage, stretching, or damaged threads. Replace any fastener that does not meet the service manual's requirements, and tighten the fasteners in the specified sequence and to the specified torque.
Is this gasket sold as a kit?
No. The package contains one exhaust manifold gasket only. It does not include an exhaust manifold, bolts, sealant, or other gaskets.
Safety & Important Information
- Verify the exact model and serial-number range before ordering.
- Compare the replacement gasket with the original part before installation. Do not install it if the outline or openings do not match.
- Work only on a cool engine and follow the manufacturer's service procedures.
- Professional installation is recommended when the required torque specifications or engine service procedures are unavailable.
- This is an aftermarket replacement component, not an OEM Mercury Marine product.
About Sea Sierra
- Marine Parts Support — We provide replacement marine components with application information to help customers make informed fitment decisions.
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- Customer Assistance — Contact support with your engine model and serial number if you need help reviewing the listed application.
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