Exhaust Elbow Gasket – Fits MerCruiser 3.7L 165-190HP (Replaces 27-18272, 27-97863)
This exhaust elbow gasket is designed for MerCruiser 4-cylinder 3.7L engines (165HP, 170HP, 180HP, 190HP, and 3.7LX models from 1985–1989) equipped with aluminum exhaust manifolds. It provides a reliable seal between the exhaust elbow and the manifold.
This part is a direct replacement for Mercury/MerCruiser part numbers 27-18272 and 27-97863, as well as several other aftermarket equivalents.
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Direct Replacement: Installs without modification, matching OEM specifications for a direct fit.
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Material: Constructed from high-quality, OEM-spec gasket material designed for use with aluminum manifolds.
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Application: Creates a durable seal for the connection between the exhaust elbow and the manifold.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury/MerCruiser |
27-18272 |
| Mercury/MerCruiser |
27-97863 |
| Sierra |
18-0881-1 |
| GLM |
32470 |
| Osco |
8561-G |
| Mallory |
9-61412 |
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 |
165 (4-Cyl.) |
165 |
4-Stroke |
1987 |
27-18272 |
Serial Range: 0B434941-0B774251 |
| MerCruiser |
170 |
170 |
4-Stroke |
1985-1986 |
27-18272 |
Serial Range: 6916779-0B434940 |
| MerCruiser |
180 |
180 |
4-Stroke |
1987 |
27-18272 |
Serial Range: 0B436391-0B775248 |
| MerCruiser |
190 |
190 |
4-Stroke |
1985-1986 |
27-18272 |
Serial Range: 6916779-0B436390 |
| MerCruiser |
3.7LX |
165-190 |
4-Stroke |
1988-1989 |
27-18272 |
Serial Range: 0B775249 & Up |
Technical Specifications
| Specification |
Value |
| Product Type |
Exhaust Elbow Gasket |
| Installation |
Direct fit |
| Housing Material |
OEM-spec gasket material |
| Housing Color |
White/Off-white |
| Connection |
Exhaust elbow to manifold |
| Other Technical Attributes |
Aluminum manifold compatible |
Package Contents
- 1 x Exhaust Elbow Gasket (Replaces 27-18272/27-97863)
Installation Guide
- Ensure the engine is completely cool and disconnect the battery for safety.
- Close the engine's seacock to prevent water from entering the exhaust system.
- Carefully disconnect any hoses or sensors attached to the exhaust elbow.
- Unbolt and remove the old exhaust elbow from the manifold.
- Thoroughly clean both the manifold and elbow mating surfaces, removing all old gasket material and corrosion.
- Ensure both surfaces are clean, dry, and perfectly flat before proceeding.
- Place the new exhaust elbow gasket onto the manifold, aligning it with the bolt holes. Do not use sealant unless explicitly required by the engine manufacturer.
- Carefully position the exhaust elbow over the new gasket and align the bolt holes.
- Insert and hand-tighten the mounting bolts to ensure proper alignment.
- Using a torque wrench, tighten the bolts to the manufacturer's specified value and sequence.
- Reconnect all hoses and sensors that were previously removed.
- Open the seacock, start the engine, and carefully inspect for any exhaust or water leaks around the new gasket.
Troubleshooting & FAQ
How do I confirm this gasket fits my 3.7L MerCruiser engine?
This gasket fits MerCruiser 4-cylinder 3.7L engines (165HP-190HP) from 1985–1989 that use aluminum exhaust manifolds. To guarantee fitment, please cross-reference your engine's serial number with the ranges provided in the "Compatible Engine Models" table above.
What are the signs that my exhaust elbow gasket is failing?
Common signs of a failed gasket include water leaking externally from the joint between the manifold and elbow, visible rust stains in this area, engine overheating, or, in severe cases, water entering the engine cylinders, which can cause significant damage.
Is any sealant required when installing this gasket?
Generally, no sealant should be used with this type of gasket. Installing it on clean, dry, and flat surfaces provides the best seal. Using sealant can sometimes cause the gasket to slip out of place or create an uneven seal, leading to leaks.
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.
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.
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.