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Full Flow Elbow Gasket – Fits MerCruiser GM V-6 & V-8 (Replaces 27-864547A02, 27-864547A1)

Regular price $27.50
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Full Flow Elbow Gasket – Fits MerCruiser GM V-6 & V-8 (Replaces 27-864547A02, 27-864547A1) is backordered and will ship as soon as it is back in stock.


Worry-free returns

You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.

Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This Full Flow Elbow Gasket – Fits MerCruiser GM V-6 & V-8 Stern Drives with Risers (Replaces 27-864547A02, 27-864547A1) is designed for MerCruiser GM V-6 and V-8 engines (2002 & newer) that feature a dry joint exhaust manifold and utilize standard cooling. It is compatible with 4.3L, 5.0L, 5.7L, and 6.2L models equipped with risers.

This part provides a direct replacement for MerCruiser part numbers 27-864547A02 and 27-864547A1, as well as Sierra 18-0721.

  • Engineered for modern dry joint exhaust systems.
  • Full flow (open) style for standard cooling applications.
  • Designed exclusively for use with exhaust risers.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand Part Number
MerCruiser 27-864547A02
MerCruiser 27-864547A1
Sierra 18-0721

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For MerCruiser owners, this gasket fits V-6 and V-8 gas stern drives manufactured from 2002 onwards with the dry joint exhaust system.

Brand Model Rated HP Stroke Years OEM Part No. Notes
MerCruiser 4.3L 4.3L 4-Stroke 2002 & Newer 27-864547A02/27-864547A1 Dry Joint Manifold with Risers
MerCruiser 5.0L 5.0L 4-Stroke 2002 & Newer 27-864547A02/27-864547A1 Dry Joint Manifold with Risers
MerCruiser 5.7L 5.7L 4-Stroke 2002 & Newer 27-864547A02/27-864547A1 Dry Joint Manifold with Risers
MerCruiser 350 MAG 5.7L 4-Stroke 2002 & Newer 27-864547A02/27-864547A1 Dry Joint Manifold with Risers
MerCruiser 6.2L 6.2L 4-Stroke 2002 & Newer 27-864547A02/27-864547A1 Dry Joint Manifold with Risers

Technical Specs

Product Type
Exhaust Elbow Gasket
Installation
Dry Joint System
Style
Full Flow (Open)
Application
Standard Cooling
Material
Metal
Shape
Rectangular
Cooling Type
Standard Cooling
Exhaust Type
Dry Joint
Other Technical Attributes
Used with risers only

What’s in the Box

  • 1 x Riser Gasket (Open) (27-864547A02/27-864547A1)

Installation Notes

  1. Ensure both the manifold and riser mating surfaces are perfectly clean and free of old gasket material, residue, or corrosion.
  2. Place the new gasket into position, confirming its orientation matches the cooling passages. This is a full-flow gasket, so all passages will be open.
  3. Carefully mount the riser, ensuring it aligns correctly without shifting the gasket.
  4. Install mounting bolts and tighten them to the manufacturer's recommended torque specifications using a calibrated torque wrench. Follow the specified tightening sequence to ensure even pressure.

Troubleshooting & FAQ

How do I know if I need a "full flow" or "restrictor" gasket?

This full flow (open) gasket is for engines with standard or raw water cooling systems. If your engine uses a closed cooling (freshwater) system, you would typically need a restrictor gasket (such as Sierra 18-0720) to regulate coolant flow. Always check your service manual to confirm the correct type for your specific setup.

Will this gasket fit an engine older than 2002?

No, this gasket is specifically designed for MerCruiser's dry joint exhaust system, which was introduced in 2002. It is not compatible with earlier wet joint systems.

What are the signs of a failing elbow gasket?

Common symptoms include visible water leaks (especially when the engine is running), rust stains originating from the joint, engine overheating, or, in severe cases, water intrusion into the cylinders, which can cause catastrophic engine damage. Regular inspection is recommended.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). It has been built to OEM-level specifications with comparable materials. Our parts are manufactured in an ISO 9002 facility and are batch-inspected for quality and consistency.

Shipping speed & cost

We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free; expedited options will appear at checkout where available for your location.

Warranty & returns

This product is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter any issues, please contact our support team with your order details. Returns are accepted within our standard window, provided the item is unused and in its 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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