Manifold Exhaust Gasket Kit – Fits MerCruiser 140/3.0L I4 Stern Drive (Replaces 27-64692, 27-99777-2, 27-92720)
This gasket kit fits MerCruiser/Mercury Marine 120, 140, and 3.0L 4-cylinder engines (153, 181 CID) manufactured from 1968 to 1982, specifically for wet joint applications.
The kit serves as a direct replacement for Mercury part numbers 27-64692 (Carburetor Base Gasket), 27-99777-2 (Exhaust Manifold to Elbow/Adaptor Gasket), and 27-92720 (Exhaust Manifold to Elbow Gasket), among others from reputable aftermarket brands.
- Includes essential gaskets for exhaust manifold and carburetor base
- Designed for wet joint model applications
- Direct replacement installation method with marine-grade gasket materials
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury |
27-64692 (Carburetor Base Gasket) |
| Mercury |
27-99777-2 (Exhaust Manifold to Elbow/Adaptor Gasket) |
| Mercury |
27-92720 (Exhaust Manifold to Elbow Gasket) |
| GLM |
31520 |
| GLM |
32630 |
| Sierra |
18-0954 |
| Mallory |
9-61415 |
| NorthBoat |
64692 Kit |
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
| 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 Specifications
| Specification |
Value |
| 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 Technical Attributes |
Heat and corrosion resistant marine-grade material |
Package Contents
- 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 (22-806608A02/22-806608A1/22-8M0119211)
- 1 x O-ring (25-26802/25-8M2000926/12-31060)
Installation Guide
- Ensure the engine is cool and safely disconnected before starting installation.
- Remove the exhaust manifold and related components as necessary to access gaskets.
- Carefully remove old gaskets and thoroughly clean the mating surfaces.
- Inspect surfaces for damage or corrosion; repair if needed before proceeding.
- Position new gaskets properly for each component following the kit contents.
- Reinstall the exhaust manifold and tighten bolts evenly to the manufacturer's torque specifications.
- Replace the drain plug and O-ring included in the kit if applicable.
- Reconnect any removed components and ensure all connections are secure.
- Start the engine and check for leaks or abnormal noises.
- Perform a test run to verify proper installation and performance.
Troubleshooting & FAQ
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How do I confirm this fits my engine? Check the compatible engine models table for your engine’s brand, model, and year. Use provided guides to identify your engine’s serial/model accurately.
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What are the differences between this aftermarket gasket kit and OEM parts? This listing is an aftermarket replacement part, made to OEM specifications with comparable-grade materials. Production is done in an ISO9002-certified facility with consistent quality inspections.
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How often should I replace the exhaust manifold gasket kit? Replacement intervals depend on usage and conditions, but inspect your gaskets regularly for leaks or damage during routine maintenance.
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What are common signs that my exhaust manifold gasket needs replacement? Look for exhaust leaks, unusual noises, overheating, or reduced engine performance as indicators of gasket failure.
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Can I install this gasket kit myself? Professional installation is recommended, but if you have mechanical experience, follow proper procedures outlined in the installation guide carefully.
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OEM vs. Aftermarket? This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
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How fast do you ship and how much does it cost? We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
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What is your warranty and return policy? This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.