Exhaust Elbow Gasket – Fits MerCruiser V6/V8 Engines 1981-1997 (Replaces 27-863724)

Exhaust Elbow Gasket – Fits MerCruiser V6/V8 Engines 1981-1997 (Replaces 27-863724)

This standard cooling restrictor gasket is designed for MerCruiser V6 and V8 stern drive and inboard engines (1981-1997) equipped with center rise outlet exhaust manifolds. It creates a reliable seal between the exhaust manifold and the riser or elbow, ensuring optimal exhaust flow while maintaining proper cooling system function.

This part is a direct replacement for Mercury/MerCruiser part numbers 27-41813, 27-860233, and 27-863724. It also replaces several aftermarket parts, including Sierra 18-0897 and GLM 30240.

• Installation Location: Mounts between the exhaust manifold and the riser/elbow.
• Gasket Style: Restrictor gasket for standard (raw water) cooling systems.
• Primary Material: Constructed from a durable metal/composite with a graphite lining to withstand the marine environment.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

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.

Technical Specifications

Package Contents

This package includes the following:

• Exhaust Elbow Gasket(s) (Replaces 27-863724)

Note: Package contents may vary based on the supplier. Aftermarket packages often contain two (2) gaskets, while OEM packages typically contain one (1). Please verify the quantity in your selected package.

Installation Guide

Professional installation is recommended. The following are general steps for replacement.

1. Disconnect the Battery: Ensure the engine is off and disconnect the battery terminals to prevent accidental starting.
2. Drain Cooling System: Partially drain the engine coolant to a level below the exhaust manifold.
3. Access the Manifold: Remove any components blocking access to the exhaust manifold and riser/elbow connection.
4. Remove Riser/Elbow: Loosen and remove the bolts securing the exhaust riser (or elbow) to the manifold.
5. Remove Old Gasket: Carefully detach the riser from the manifold and remove the old gasket. Note its orientation.
6. Clean Mating Surfaces: Thoroughly clean both the manifold and riser surfaces. Ensure they are free of old gasket material, rust, and debris for a proper seal.
7. Install New Gasket: Place the new gasket onto the manifold, ensuring it is correctly aligned with the bolt holes and water passages.
8. Re-attach Riser/Elbow: Re-position the riser onto the new gasket and loosely thread the bolts by hand.
9. Torque to Specs: Tighten the bolts in a crisscross pattern to the manufacturer's recommended torque specifications to ensure an even seal. Do not overtighten.
10. Final Checks: Reconnect all previously removed components and refill the cooling system. Reconnect the battery.
11. Test for Leaks: Start the engine and let it reach operating temperature. Carefully check the gasket area for any signs of water or exhaust leaks.

Troubleshooting & FAQ

How do I confirm this fits my engine?
First, check the Compatible Engine Models table on this page. Verify your MerCruiser model, HP, and year range (1981-1997). Second, cross-reference your existing part number with the numbers listed in the "Part Number Cross-Reference" table, such as 27-863724, 27-860233, or Sierra 18-0897.

What are the signs of a failing exhaust elbow gasket?
Common signs include visible water leaks around the manifold/riser joint (especially when the engine is running), rust or corrosion trails originating from the joint, engine overheating, or water intrusion into the cylinders, which can cause significant engine damage.

What is a "restrictor" gasket and why is it used?
This is a restrictor-style gasket, meaning some of its water passages are intentionally smaller than others. It is designed for standard (raw water) cooling systems to regulate water flow, ensuring the engine operates at the correct temperature. Using the wrong gasket type (e.g., a full-flow gasket on a standard cooling system) can cause the engine to run too cool.

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?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.