Exhaust Gasket Kit – Fits MerCruiser 140/3.0L I4 (Replaces 27-64692, 27-99777-2, 27-92720)

$16.50

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Exhaust Gasket Kit – Fits MerCruiser 140/3.0L I4 (Replaces 27-64692, 27-99777-2, 27-92720) is backordered and will ship as soon as it is back in stock.

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Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This aftermarket Manifold Exhaust Gasket Kit is engineered for MerCruiser 120, 140, 2.5L, and 3.0L 4-cylinder engines (153 & 181 CID) from 1968–1982, specifically for wet joint applications. It provides the essential seals needed to prevent exhaust and water leaks between the manifold, elbow, and carburetor base.

It serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury 27-64692, 27-99777-2, and 27-92720, as well as equivalents from GLM, Sierra, and Mallory.

Designed for direct, hassle-free installation.
Specifically suited for wet joint exhaust systems.
Made from heat and corrosion-resistant marine-grade materials.

Part Number Matrix

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

Brand	Part Number
Mercury	27-64692
Mercury	27-99777-2
Mercury	27-92720
GLM	31520
GLM	32630
Sierra	18-0954
Mallory	9-61415
NorthBoat	64692 Kit

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This kit is designed for the following MerCruiser/Mercury Marine engines.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
MerCruiser	120	120	4-Stroke	1983–1986	27-99777-2, 27-64692	GM 153 CID I/L4 (S/N 6229718-0B531853)
MerCruiser	120	120	4-Stroke	1979–1982	27-99777-2, 27-64692, 27-92720	GM 153 CID I/L4 (S/N 5192049-6229717)
MerCruiser	120	120	4-Stroke	1972–1978	27-99777-2, 27-64692, 27-92720	GM 153 CID I/L4 (S/N 3377341-5192048)
MerCruiser	140	140	4-Stroke	1982–1986	27-99777-2, 27-64692, 27-92720	GM 181 CID I/L4 (S/N 6229718-0B450800)
MerCruiser	140	140	4-Stroke	1979–1982	27-99777-2, 27-64692, 27-92720	GM 181 CID I/L4 (S/N 5157669-6229717)
MerCruiser	140	140	4-Stroke	1972–1978	27-99777-2, 27-64692, 27-92720	GM 181 CID I/L4 (S/N 3332138-5157668)
MerCruiser	2.5L	120	4-Stroke	1987–1989	27-99777-2, 27-64692	GM 153 CID I/L4 (S/N 0B531854-0C856558)
MerCruiser	3.0L	140	4-Stroke	1987–1989	27-99777-2, 27-64692	GM 181 CID I/L4 (S/N 0B450801-0C856558)
MerCruiser	165	165	4-Stroke	1979–1981	27-64692	GM 250 I/L6 (S/N 5178959 and up)
MerCruiser	165	165	4-Stroke	1970–1978	27-64692	GM 250 I/L6 (S/N 2770032-5178958)

Technical Specs

Product Type: Exhaust Manifold Gasket Kit
Installation: Direct replacement
Material: Marine Grade Gasket Material
Applications: Wet Joint Model Applications
Compatible Engines: MerCruiser 140 - Inline 4, GM 181 CID, 4-CYL (1968-82)
Weight: 0.05 kg (0.11 lb) approx.
Other Attributes: Heat and corrosion resistant marine-grade material

What’s in the Box

Kit contents typically include:

1 x Rear Riser - Open Gasket - Exhaust Manifold to Elbow or Adaptor (27-99777-2)
1 x Rear Riser - Gasket - Exhaust Manifold to Elbow for closed cooling (27-92720)
1 x Gasket - Carburetor Base (Rochester) (27-64692)
1 x Drain Plug (22-806608A02)
1 x O-ring (25-26802)

Installation Notes

Disconnect the battery and drain coolant/water from the exhaust manifold.
Carefully label and disconnect any hoses, wires, or sensors attached to the exhaust riser and manifold.
Unbolt and remove the exhaust elbow/riser.
Unbolt and remove the exhaust manifold from the cylinder head.
Thoroughly clean all mating surfaces on the head, manifold, and riser. Ensure they are free of old gasket material, rust, and debris.
Position the new gaskets correctly. Do not use any sealant unless specified by the engine manufacturer.
Reinstall the manifold and tighten the bolts in the sequence and to the torque specs recommended by the manufacturer.
Mount the elbow/riser with its new gasket, tightening bolts to the correct specification.
Reconnect all previously removed hoses, wires, and sensors.
Refill the cooling system.
Start the engine and carefully check for any water or exhaust leaks around the newly installed gaskets.

Troubleshooting & FAQ

How do I know if this kit fits my specific engine model?

The best way is to cross-reference your engine's serial number or original part numbers with our compatibility table. This kit is designed for "wet joint" MerCruiser models listed, primarily from 1968-1982. Please verify the part numbers in your service manual.

What is a "wet joint" exhaust application?

A "wet joint" system is one where engine cooling water passes through the joint between the exhaust manifold and the riser/elbow. This kit is specifically designed to seal these water passages correctly.

What are the signs of a leaking exhaust manifold gasket?

Common symptoms include water leaking externally from the manifold/riser joint, steam in the engine bay, an overheating engine, or, in severe cases, water entering the engine's cylinders, which can cause catastrophic damage. Prompt replacement is crucial.

Is this a complete kit for the job?

This kit includes the primary gaskets for the manifold-to-riser, alternate riser, and carburetor base connections as detailed in the "What's in the Box" section. However, depending on your specific setup, other seals or hardware may be needed. Always consult your service manual.

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.

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