Exhaust Elbow Riser Gasket Dry Joint for MerCruiser – 27-864549A02
This dry joint exhaust elbow riser gasket is engineered for MerCruiser marine engines equipped with closed cooling systems. Designed to fit GM V-6 and V-8 engines (2002 and newer) utilizing dry joint exhaust manifolds, this gasket ensures a reliable seal between the riser and manifold components.
This gasket directly replaces OEM part number 27-864549A02, 27-864549A1, and 27-864549, as well as Sierra part number 18-0720. It is compatible with MerCruiser engines ranging from 4.3L to 6.2L that use the dry joint manifold and riser configuration with closed cooling.
- Designed specifically for closed cooling systems with blocked-off gasket configuration
- Fits 4.3L, 5.0L, 5.7L, and 6.2L MerCruiser engines with dry joint exhaust manifolds
- Direct replacement for multiple OEM and aftermarket part numbers
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands:
| Brand |
Part Number |
Notes |
| MerCruiser (OEM) |
27-864549A02 |
Primary OEM number |
| MerCruiser |
27-864549A1 |
Superseded by 27-864549A02 |
| MerCruiser |
27-864549 |
Superseded by 27-864549A02 |
| Sierra |
18-0720 |
Aftermarket equivalent |
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 |
Engine Displacement |
Years |
Notes |
| MerCruiser |
GM V-6 & V-8 |
4.3L, 5.0L, 5.7L, 6.2L |
2002 & newer |
Dry joint exhaust manifold with closed cooling system only |
Technical Specifications
| Specification |
Value |
| OEM Part Number |
27-864549A02 |
| Gasket Type |
Dry Joint |
| Cooling System |
Closed Cooling (blocked-off configuration) |
| Application |
Exhaust Elbow Riser to Manifold |
| Compatible Engines |
GM V-6 & V-8 (4.3L, 5.0L, 5.7L, 6.2L) |
| Model Year |
2002 and newer |
Package Contents
- Exhaust Elbow Riser Gasket (Dry Joint) – Qty: 1
Installation Guide
- Ensure the engine is completely cool and disconnect the battery to prevent accidental start-up.
- Remove the exhaust elbow riser assembly by loosening and removing all mounting bolts. Support the riser as you work to prevent damage.
- Carefully separate the riser from the exhaust manifold and inspect both mating surfaces for corrosion, pitting, or damage.
- Clean both the manifold and riser mounting surfaces thoroughly using a gasket scraper and appropriate solvent. Remove all old gasket material and debris.
- Inspect the riser and manifold for cracks or excessive wear; replace components if necessary before proceeding.
- Position the new dry joint gasket onto the exhaust manifold, ensuring all bolt holes and passages are properly aligned.
- Carefully place the exhaust elbow riser onto the gasket, aligning all mounting holes. Do not use sealant on dry joint gaskets unless specified by the manufacturer.
- Install mounting bolts finger-tight first to ensure proper alignment and seating of the gasket.
- Torque the mounting bolts to manufacturer specifications in a cross-pattern sequence to ensure even clamping pressure.
- Reconnect the battery and start the engine, allowing it to reach operating temperature while monitoring for exhaust leaks.
- Inspect all connections and gasket areas for signs of exhaust gas or water leakage during initial operation.
- Shut down the engine, allow it to cool, and re-check bolt torque after the first heat cycle to ensure proper seating.
Troubleshooting & FAQ
Q: How do I confirm this gasket fits my MerCruiser engine?
A: Verify that your engine is a GM V-6 or V-8 (4.3L, 5.0L, 5.7L, or 6.2L) manufactured in 2002 or later with a dry joint exhaust manifold and closed cooling system. Check your existing gasket part number against 27-864549A02, 27-864549A1, or Sierra 18-0720 for confirmation.
Q: What is the difference between dry joint and wet joint gaskets?
A: Dry joint gaskets are used in closed cooling systems where the gasket has a blocked-off design to prevent coolant passage. Wet joint gaskets allow coolant flow and are used in different manifold configurations. Using the wrong type will result in leaks or cooling system failure.
Q: How often should I replace my exhaust riser gasket?
A: Replace the gasket any time you remove the exhaust elbow riser for service or repair. Gaskets are single-use components that compress during installation and should not be reused. Inspect the gasket annually for signs of deterioration, especially in saltwater environments.
Q: Can I reuse this gasket if I need to remove the riser again?
A: No, exhaust gaskets should never be reused. Once compressed and exposed to heat cycles, the gasket material loses its ability to seal properly, which can lead to exhaust leaks and potential engine damage.
Q: What are the signs of a failing exhaust riser gasket?
A: Common symptoms include visible exhaust leaks (smoke or soot) around the riser-to-manifold junction, hissing sounds during operation, reduced engine performance, and in severe cases, water intrusion into the exhaust system or engine overheating.
Q: Is this an OEM or aftermarket part?
A: 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.
Q: How fast do you ship and how much does it cost?
A: 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.
Q: What is your warranty and return policy?
A: 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.