Exhaust Gasket – Fits Mercruiser 140HP 4cyl 181 CID (Replaces 27-53354, 908079, 18-2912, 17301)

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Exhaust Gasket – Fits Mercruiser 140HP 4cyl 181 CID (Replaces 27-53354, 908079, 18-2912, 17301) is backordered and will ship as soon as it is back in stock.

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Product Details

This aftermarket Exhaust Gasket – Fits Mercruiser 140HP 4cyl 181 CID (Replaces 27-53354, 908079, 18-2912, 17301) is designed for Mercruiser 4-Cylinder engines, including 140 HP and 181 CID models, typically from the years 1968–1982. It serves as a direct replacement gasket used to mount the MC-1-52390 exhaust manifold securely to the cylinder heads, ensuring a proper seal.

This part provides a direct interchange for several OEM and aftermarket part numbers, including Mercury Marine 27-53354, OMC 908079, Aftermarket 18-2912, Aftermarket 17301, GLM 31570, and MC47-27-53354.

Installation: Mounts between the exhaust manifold and the cylinder head.
Engine Fitment: Compatible with specific Mercruiser 4-Cylinder 140 HP models.
Construction: Built to meet or exceed OEM specifications for a reliable seal.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand	Part Number
Mercury Marine	27-53354
OMC	908079
Aftermarket	18-2912
Aftermarket	17301
GLM	31570
Aftermarket (Barr)	MC47-27-53354

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This gasket is documented to fit a range of Mercruiser 4-cylinder engines. Note the specific serial ranges for precise compatibility.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Mercruiser	140	140	4-Stroke	1968–1972	27-53354	Serial Range: 2508261 THRU 3332137
Mercruiser	140	140	4-Stroke	1972–1978	27-53354	Serial Range: 3332138 THRU 5157668
Mercruiser	140	140	4-Stroke	1979–1982	27-53354	Serial Range: 5157669 THRU 6229717
Mercruiser	181	140	4-Stroke	1968–1982	27-53354	4-Cylinder
Mercruiser	2.5L		4-Stroke	1968–1982 (Approximate)	27-53354	Found in a kit with 2.5L and 3.0L compatibility
Mercruiser	3.0L		4-Stroke	1968–1982 (Approximate)	27-53354	Found in a kit with 2.5L and 3.0L compatibility
Mercruiser	MCM 140	140	4-Stroke	1968–1982	27-53354	Part fits this model
OMC					908079	Referenced as OMC equivalent for 27-53354

Technical Specs

Product Type: Exhaust Manifold Gasket
Installation: Exhaust Manifold to Cylinder Head
Dimensions: Length: 495 mm (19.49 in) | Width: 5 mm (0.20 in) | Height: 70 mm (2.76 in)
Weight: 0.088 kg (0.19 lb)
Warranty: 90 Day (Aftermarket)

Installation Notes

Ensure the engine is completely cool before beginning work.
Disconnect the boat's battery to prevent accidental starts.
Remove any components that obstruct access to the exhaust manifold.
Carefully unbolt and detach the old exhaust manifold from the cylinder head.
Thoroughly clean both the cylinder head and the manifold mating surfaces, removing all old gasket material and debris. A clean, smooth surface is critical for a proper seal.
Position the new gasket correctly over the cylinder head exhaust ports.
Carefully place the exhaust manifold over the new gasket and start all bolts by hand.
Tighten the manifold bolts in the sequence and to the torque values specified by the engine manufacturer.
Reinstall any components that were removed earlier.
Reconnect the battery.
Start the engine and carefully check for any signs of exhaust leaks around the manifold.

Troubleshooting & FAQ

How do I confirm this gasket fits my specific engine model?

Check the Engine & Model Compatibility table on this page. Compare your engine's model, horsepower, and year. For Mercruiser models, also verify your engine's serial number falls within the specified ranges.

What are the signs of a failing exhaust manifold gasket?

Common symptoms include a loud ticking or hissing noise from the engine bay that is more noticeable on a cold start, reduced engine performance, a smell of exhaust fumes in the engine bay or cabin, and visible soot or black streaks around the manifold-to-head connection.

The compatibility table lists 181 CID, 2.5L, and 3.0L. Are they the same?

These engine sizes are closely related. The Mercruiser 181 CID engine is approximately 3.0L. The 2.5L is a smaller variant. This gasket is listed as compatible with kits covering both 2.5L and 3.0L models from the same era, indicating broad interchangeability for the 4-cylinder block design from 1968-1982.

Does this gasket require sealant upon installation?

Generally, this type of gasket is designed to be installed dry. Applying sealant can sometimes interfere with a proper seal. Always follow the specific instructions in your engine's service manual.

What is the difference between OEM and aftermarket parts?

This listing is an aftermarket replacement, not an original equipment manufacturer (OEM) part. It has been engineered to meet or exceed OEM-level specifications using comparable high-quality materials. Our parts are manufactured in an ISO 9002 certified facility and are batch-inspected to ensure quality and consistency.

How much is shipping and how fast will it arrive?

We ship worldwide quickly—typical transit time is 5–15 days. Standard shipping is free to most regions, with expedited options available at checkout where applicable.

What is the warranty and return policy?

This part is covered by a 1-year warranty against manufacturing defects under normal use. If you experience an issue, please contact our support team with your order details. Returns are accepted within our standard window for items that are unused and in their original condition. See our full policy page or contact us 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.

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