Exhaust Full-Flow Elbow Gasket for MerCruiser V6 and V8 Wet-Joint Applications – Replaces 27-863726
Exhaust Full-Flow Elbow Gasket for MerCruiser V6 and V8 Wet-Joint Applications – Replaces 27-863726 is backordered and will ship as soon as it is back in stock.
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Exhaust Full-Flow Elbow Gasket for MerCruiser V6 and V8 Wet-Joint A...
Exhaust Full-Flow Elbow Gasket for MerCruiser V6 and V8 Wet-Joint Applications – Replaces 27-863726 is backordered and will ship as soon as it is back in stock.
Product Details
This aftermarket full-flow exhaust elbow gasket seals the joint between the exhaust manifold or spacer and the exhaust riser/elbow on compatible MerCruiser stern-drive applications. It is an open-port gasket for specified wet-joint exhaust systems and is intended to replace the corresponding original gasket when the part number, exhaust design, and engine conditions match.
The gasket is listed for MerCruiser V6 and V8 wet-joint applications covering GM 229/262 CID V6 engines, GM 305/350/377 CID small-block V8 engines, and GM 454/502 CID big-block V8 engines. Confirm the engine model, serial-number range, manifold design, cooling system, and existing gasket before ordering.
- Full-flow, open-port exhaust elbow gasket.
- Installs between the exhaust manifold or spacer and the exhaust riser/elbow.
- Designed for the wet-joint applications listed below.
- Single replacement gasket; mounting hardware, risers, spacers, and other seals are not included.
Part Number Cross-Reference
Use the following references to compare the gasket with your original part. Cross-reference numbers identify cataloged replacement or interchange references; they do not replace checking the complete application.
| Brand or Source | Part Number | Reference Type |
|---|---|---|
| MerCruiser | 27-863726 | Original-equipment reference |
| MerCruiser | 27-818832 | Replacement reference |
| MerCruiser | 27-860232 | Replacement reference |
| MerCruiser | 27-87105 | Replacement reference |
| MerCruiser | 27-871051 | Replacement reference |
| Mercury Marine | 87105 | Number variation |
| Mercury Marine | 860232 | Number variation |
| Sierra | 18-2849-1 | Open exhaust elbow gasket reference |
| GLM | 32080 | Aftermarket reference |
| Mallory Marine | 9-61414 | Aftermarket reference |
| OMC | 0508606 | Additional catalog reference |
Engine and Application Compatibility
The application groups below preserve the engine type, displacement, application style, and serial conditions together. The “0M” notation is retained from the catalog fitment data; verify the complete serial number against the engine manufacturer’s catalog before installation.
| Engine Group | Engine Type | GM Block / Displacement | Application | Year or Serial Condition | Gasket Style |
|---|---|---|---|---|---|
| MerCruiser Model 175–205 | V6 | 229/262 CID | Wet-joint exhaust manifold and riser/elbow | 1983 through 0M serial numbers | Full-flow/open |
| MerCruiser Model 200–320 | Small-block V8 | 305/350/377 CID | Wet-joint exhaust manifold and riser/elbow | 1983 through 0M serial numbers | Full-flow/open |
| MerCruiser Model 330–370 | Big-block V8 | 454/502 CID | Wet-joint exhaust manifold and riser/elbow | 1981 and later | Full-flow/open |
| MerCruiser V6/V8 small-block applications | V6 or V8 | Confirm the GM block | Dry-joint alternative application only where the engine and manifold configuration specifically calls for this gasket | 0M serial numbers and later | Verify before use |
Important: This is an open, full-flow gasket. Do not substitute it for a restricted, blocked, or closed-cooling gasket unless the engine and exhaust-manifold documentation specifically calls for the open design. Similar-looking riser gaskets can have different water-port configurations.
Technical Specifications
- Product Type
- Exhaust manifold and riser/elbow gasket
- Design
- Full-flow, open-port design
- Installation Location
- Between the exhaust manifold or spacer and the exhaust riser/elbow
- Primary Application
- MerCruiser stern-drive wet-joint exhaust systems
- Engine Coverage
- Specified GM V6 and V8 applications listed in the compatibility table
- Replacement Reference
- MerCruiser 27-863726
- Package Quantity
- 1 gasket
What's in the Box
- 1 × full-flow exhaust elbow gasket
Risers, exhaust manifolds, spacers, bolts, O-rings, sealants, and additional manifold gaskets are not included.
Installation Notes
- Allow the engine and exhaust system to cool completely. Disconnect the battery and follow the boat manufacturer's safety procedures.
- Close the seacock or otherwise isolate the raw-water supply as required for your cooling-system configuration.
- Disconnect the hoses, sensors, and other components that prevent access to the riser/elbow joint.
- Remove the riser/elbow mounting bolts and carefully separate the riser from the manifold or spacer.
- Remove the old gasket and clean both mating surfaces thoroughly. Do not damage the sealing surfaces.
- Inspect the manifold and riser for corrosion, pitting, distortion, or blocked water passages. Replace damaged components before fitting the new gasket.
- Confirm that the new gasket's open ports and bolt holes match the original gasket and the manifold/riser configuration.
- Install the gasket dry unless the engine manufacturer's instructions specify an approved sealant. Do not use sealant to alter or obstruct the water passages.
- Reinstall the riser/elbow and tighten the fasteners in the manufacturer's specified sequence and torque.
- Reconnect all hoses and sensors, restore the cooling-water supply, reconnect the battery, and check carefully for exhaust or water leaks during the initial run.
Maintenance and Troubleshooting
How do I confirm that this gasket fits my engine?
Compare the existing gasket's part number, port pattern, bolt-hole pattern, engine displacement, wet-joint or dry-joint configuration, cooling-system type, and complete serial number with the compatibility information above. If any of these conditions differ, consult the engine or exhaust-manifold parts catalog before ordering.
Is this gasket full-flow or restricted?
This is a full-flow, open-port gasket. It must not be used in place of a restricted or blocked gasket. Using the wrong port design can disrupt exhaust-manifold cooling and may cause overheating or serious engine damage.
Where is the gasket installed?
It is installed at the joint between the exhaust manifold or manifold spacer and the exhaust riser/elbow.
Can I reuse the old gasket?
No. Remove and replace the gasket whenever the riser/elbow is removed. Reusing a compressed gasket can result in exhaust or cooling-water leaks.
What are common signs of a failed exhaust elbow gasket?
Possible signs include external water or exhaust leakage at the joint, an overheating condition, steam or unusual exhaust odor, or water intrusion into the engine. Stop operation and investigate immediately if water may be entering the cylinders.
Is this an OEM component?
This listing is for an aftermarket replacement gasket. MerCruiser and other manufacturer numbers are shown only as identification and cross-reference references.
Safety and Important Information
- Verify the complete engine model, displacement, serial number, exhaust-manifold design, cooling system, and gasket port pattern before purchase.
- Do not use this open gasket on a restricted, blocked, or closed-cooling application unless the manufacturer's documentation confirms compatibility.
- Exhaust-system work involves hot components, cooling water, and potentially hazardous fumes. Professional installation is recommended.
- Follow the engine manufacturer's torque specifications and installation procedures.
About Sea Sierra
- Marine Replacement Parts — We supply replacement components for common marine engine and stern-drive service applications.
- Application-Focused Listings — Product information is organized around part references, engine groups, and installation location.
- Support for Fitment Checks — Compare your original part and engine identification details before ordering.
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