Aftermarket Manifold Exhaust Gasket Kit for MerCruiser 140 / 3.0L I4 Stern Drive – Replaces 27-64692, 27-99777-2, 27-92720
Aftermarket Manifold Exhaust Gasket Kit for MerCruiser 140 / 3.0L I4 Stern Drive – 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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Aftermarket Manifold Exhaust Gasket Kit for MerCruiser 140 / 3.0L I...
Aftermarket Manifold Exhaust Gasket Kit for MerCruiser 140 / 3.0L I4 Stern Drive – Replaces 27-64692, 27-99777-2, 27-92720 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket manifold exhaust gasket kit is intended for selected MerCruiser 140 and 3.0L inline 4-cylinder stern-drive applications. It provides replacement gaskets for wet-joint exhaust connections and related sealing points, helping prevent exhaust and cooling-water leaks between the manifold, elbow or riser, adaptor, and carburetor base.
The kit is listed as a replacement for Mercury references 27-64692, 27-99777-2, and 27-92720. Always compare the original gasket, engine serial number, and service-manual specifications before ordering.
- Replacement manifold and exhaust-joint gasket set for applicable MerCruiser stern-drive engines.
- Designed for wet-joint exhaust applications identified by the applicable reference numbers.
- Made from marine-grade gasket material suitable for heat and moisture exposure.
- Supplied as an aftermarket replacement rather than a Mercury OEM component.
Part Number Matrix
These references are provided for cross-reference purposes. Number co-occurrence does not replace checking the engine application and gasket configuration.
| Brand or Source | 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 and Model Compatibility
The application information below reflects the listed MerCruiser 140 and 3.0L I4 stern-drive references. Confirm the complete serial-number range and exhaust configuration for your engine before installation.
| Brand | Model | Rated HP | Stroke | Years | OEM Part References | Engine and Serial-Number Conditions |
|---|---|---|---|---|---|---|
| MerCruiser | 140 | 140 | 4-Stroke | 1972–1978 | 27-99777-2, 27-64692, 27-92720 | GM 181 CID inline 4-cylinder; serial numbers 3332138–5157668 |
| MerCruiser | 140 | 140 | 4-Stroke | 1979–1982 | 27-99777-2, 27-64692, 27-92720 | GM 181 CID inline 4-cylinder; serial numbers 5157669–6229717 |
| MerCruiser | 140 | 140 | 4-Stroke | 1982–1986 | 27-99777-2, 27-64692, 27-92720 | GM 181 CID inline 4-cylinder; serial numbers 6229718–0B450800 |
| MerCruiser | 3.0L | 140 | 4-Stroke | 1987–1989 | 27-99777-2, 27-64692 | GM 181 CID inline 4-cylinder; serial numbers 0B450801–0C856558 |
Technical Specifications
- Product Type
- Manifold exhaust gasket kit
- Application
- Selected MerCruiser 140 and 3.0L I4 stern-drive applications
- Installation
- Replacement installation using the applicable original-equipment procedures
- Exhaust Configuration
- Wet-joint applications associated with the listed references
- Material
- Marine-grade gasket material
- OEM References
- 27-64692, 27-99777-2, and 27-92720
- Approximate Weight
- 0.05 kg (0.11 lb)
What's in the Box
The listed kit contents are intended to cover the applicable exhaust and carburetor-base sealing points. Verify the exact gasket configuration against the engine being serviced because some referenced applications use different exhaust arrangements.
- 1 x Rear riser open gasket for the exhaust manifold to elbow or adaptor connection, reference 27-99777-2
- 1 x Rear riser gasket for the exhaust manifold to elbow connection used with closed-cooling configurations, reference 27-92720
- 1 x Rochester carburetor-base gasket, reference 27-64692
- 1 x Drain plug, reference 22-806608A02
- 1 x O-ring, reference 25-26802
Installation Notes
- Disconnect the battery and allow the engine to cool completely.
- Drain the applicable coolant or cooling water before opening the exhaust system.
- Label and disconnect hoses, wires, and sensors attached to the manifold, elbow, or riser.
- Unbolt and remove the exhaust elbow or riser as required by the engine configuration.
- Remove the exhaust manifold if the manifold-to-cylinder-head gasket is being serviced.
- Clean all mating surfaces thoroughly. Remove old gasket material, rust, scale, and debris without damaging the sealing faces.
- Position the correct new gasket for the specific connection. Do not apply sealant unless the engine manufacturer specifies it.
- Reinstall the manifold and tighten fasteners in the manufacturer-specified sequence and to the specified torque.
- Install the elbow or riser with the correct gasket and tighten its fasteners to the service-manual specification.
- Reconnect all hoses, wires, and sensors, then refill the cooling system as required.
- Run the engine and inspect the manifold, elbow, riser, and surrounding connections for exhaust or cooling-water leaks.
Troubleshooting and FAQ
How do I confirm fitment for my engine?
Compare the engine model, year, serial number, exhaust configuration, and original gasket or part number with the compatibility information above. The 140 and 3.0L designations alone may not identify every exhaust configuration, so consult the engine service manual when the serial number or joint style is uncertain.
What is a wet-joint exhaust application?
A wet-joint exhaust system has cooling water passing through or near the manifold-to-elbow or riser connection. The gasket must correctly seal both the exhaust path and the applicable water passages.
What are common symptoms of a leaking exhaust gasket?
Possible symptoms include external water or exhaust leakage at the manifold or riser joint, steam or odor in the engine compartment, overheating, or water entering an engine cylinder. Stop operation and investigate promptly if any of these conditions occur.
Is this a complete kit for every listed engine?
The kit includes the gasket and sealing components listed in the What's in the Box section. The required contents can vary with the exhaust and cooling configuration, and additional seals, fasteners, or hardware may be needed for a particular repair.
Is this an OEM part?
No. This is an aftermarket replacement kit listed against the stated Mercury reference numbers. It is not represented as a Mercury OEM component.
What should I do if the supplied gasket differs from my original?
Do not force installation or modify the gasket. Compare the shape, ports, bolt pattern, and reference number with the service-manual requirement for your serial-number range before proceeding.
Safety and Important Information
- Verify the engine serial number, original gasket, and exhaust configuration before purchase and installation.
- Do not operate the engine if exhaust gases or cooling water are leaking into the engine compartment.
- Use the manufacturer's torque values and tightening sequence for all manifold and riser fasteners.
- This is an aftermarket replacement kit, not an OEM Mercury component.
- Professional installation is recommended when access is restricted or the exhaust system has corrosion or damaged mating surfaces.
About Sea Sierra
- Pro-Grade Standards — We supply marine replacement parts selected for demanding real-world service conditions.
- Fast Global Fulfillment — Standard delivery options are available to most regions, with timing shown at checkout.
- Manufacturer-Direct Value — Fair pricing supported by practical aftermarket replacement solutions.
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