Restricted Elbow Gasket – Fits MerCruiser V6/V8 Engines (Replaces 27-863724, 27-863724Q)
Restricted Elbow Gasket – Fits MerCruiser V6/V8 Engines (Replaces 27-863724, 27-863724Q) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Free standard shipping on all orders under 1 KG
Restricted Elbow Gasket – Fits MerCruiser V6/V8 Engines (Replaces 2...
Product Details
This Restricted Elbow Gasket – Fits MerCruiser V6/V8 Engines (Replaces 27-863724, 27-863724Q) is designed for MerCruiser stern drive and inboard engines with V6 and V8 General Motors motors (4.3L, 5.0L, 5.7L, 7.4L, 8.2L) from approximately 1981 to 1997, specifically for models featuring center rise outlet exhaust manifolds.
It serves as a direct replacement for Mercury/Quicksilver 27-863724/27-863724Q, Sierra 18-0897, GLM 30240, and OMC/BRP 508716.
- Installation: Fits between the exhaust manifold and riser elbow.
- Design: Restrictor-type gasket with a partially open design for standard cooling systems on restricted-flow engines.
- Compatibility: For manifold part numbers 98502A2, 44354A3, 98504A3, and 807914A1.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury/Quicksilver | 27-863724 |
| Mercury/Quicksilver | 27-863724Q |
| Sierra | 18-0897 |
| GLM | 30240 |
| OMC/BRP | 508716 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser models, this gasket is intended for engines with center rise exhaust manifolds, including various TBI, EFI, MPI, MIE, Bravo, and Horizon configurations within the specified years.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 4.3LX (2 BBL.) | 262 V-6 | 4-Stroke | 1996–1997 | 27-863724 | For engines with center rise exhaust |
| MerCruiser | 5.0L/5.7L EFI | 305 V-8 | 4-Stroke | 1998 | 27-863724 | For engines with center rise exhaust |
| MerCruiser | 5.7L (2 BBL.) | 350 V-8 | 4-Stroke | 1997 | 27-863724 | For engines with center rise exhaust |
| MerCruiser | 5.7L SKI | 350 V-8 | 4-Stroke | 1997 | 27-863724 | For engines with center rise exhaust |
| MerCruiser | 5.7L | 350 V-8 | 4-Stroke | 1997 | 27-863724 | For engines with center rise exhaust |
| MerCruiser | 5.7LX EFI (4 BBL.) | 350 V-8 | 4-Stroke | 1997 | 27-863724 | For engines with center rise exhaust |
| MerCruiser | 350 MAG | 350 V-8 | 4-Stroke | 1998-After | 27-863724 | For engines with center rise exhaust |
| MerCruiser | 7.4L (BRAVO VI) | 454 V-8 | 4-Stroke | 1996–1997 | 27-863724 | For engines with center rise exhaust |
| MerCruiser | 7.4LX (MPI/BRAVO VI) | 454 V-8 | 4-Stroke | 1996–1997 | 27-863724 | For engines with center rise exhaust |
| MerCruiser | 7.4L (LH BRAVO VI) | 454 V-8 | 4-Stroke | 1996–1997 | 27-863724 | For engines with center rise exhaust |
| MerCruiser | 8.2L (BRAVO VI) | 502 V-8 | 4-Stroke | 1996 | 27-863724 | For engines with center rise exhaust |
| MerCruiser | 502 MAG (BRAVO VI) | 502 V-8 | 4-Stroke | 1996 | 27-863724 | For engines with center rise exhaust |
| MerCruiser | V6/V8 GM Engines | 4.3L-8.2L | 4-Stroke | 1981–1997 | 27-863724 | For TBI, EFI, MPI, MIE, Bravo, Horizon configurations |
Technical Specs
- Product Type
- Exhaust Elbow Gasket (Restrictor)
- Installation
- Between manifold and riser elbow
- Connection
- Manifold-to-riser elbow
- Dimensions
- 14.0 x 13.0 x 1.0
- Weight
- 50 g (1.76 oz)
- Fitting Type
- Flat gasket with restricted flow opening
- Warranty
- 1 year (Mercury/Quicksilver products)
- Other Technical Attributes
- Standard cooling, restrictor type gasket with partially open design for restricted flow engines
What’s in the Box
- 2 x Gasket Manifold Restrictor Elbow (27-863724Q)
Installation Notes
- Disconnect the boat's battery for safety.
- Drain the engine coolant from the exhaust manifold system.
- Carefully disconnect any hoses or sensors attached to the riser/elbow.
- Unbolt and remove the exhaust riser or elbow from the manifold.
- Remove the old gasket and thoroughly clean both mating surfaces. Ensure they are free of old gasket material, rust, and debris.
- Place the new restricted elbow gasket onto the manifold, ensuring correct orientation.
- Reinstall the riser/elbow and tighten bolts to the manufacturer's recommended torque specification and sequence.
- Reconnect all hoses and sensors.
- Refill the cooling system.
- Reconnect the battery, start the engine, and carefully check for any exhaust or water leaks around the gasket.
Troubleshooting & FAQ
How do I know if this restricted gasket is correct for my engine?
This gasket is for specific MerCruiser V6/V8 engines with standard (not high-capacity) cooling systems from approximately 1981–1997. Verify your engine model and year against our compatibility table. Restricted gaskets are used to regulate water flow and maintain proper engine operating temperature; using the wrong type can cause overheating or overcooling.
What is the purpose of a "restrictor" gasket versus a fully open one?
A restrictor gasket has a partially blocked passage to limit the volume of cooling water exiting the manifold. This is critical for "standard cooling" systems to ensure the engine warms up to and maintains its correct operating temperature. Using a fully open gasket on an engine designed for a restricted one can lead to overcooling, poor performance, and increased engine wear.
Do I need to use a sealant or adhesive with this gasket?
Generally, these gaskets are designed to be installed dry. The gasket material is made to create a seal when compressed. Applying sealant can sometimes interfere with the seal or cause parts of the sealant to break off and clog cooling passages. Always follow your engine's service manual, but dry installation is standard practice.
What are the signs of a failing exhaust elbow gasket?
Common symptoms include water leaking externally from the joint between the manifold and elbow, steam in the engine bay, or engine overheating. A more serious internal leak can allow water to enter the engine cylinders, causing catastrophic engine damage. Regular inspection is crucial.
How often should I replace these gaskets?
Exhaust gaskets are a routine maintenance item, especially for boats operated in saltwater. It is recommended to inspect them annually and replace them every 3-5 years or whenever the manifolds or risers are serviced, whichever comes first. Proactive replacement prevents costly engine damage.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9001 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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