Exhaust Manifold Gasket – Fits MerCruiser V6 175-205 HP/262 CID (Replaces 27-99757, 18-2909-9)

Exhaust Manifold Gasket – Fits MerCruiser V6 175-205 HP/262 CID (Replaces 27-99757, 18-2909-9)

This exhaust manifold gasket provides a reliable seal between the exhaust manifold and the cylinder head. It is designed for a wide range of MerCruiser V6 GM 229/262 CID engines (175–205 HP) from 1983 and up, including 4.3L models through 2004, covering both Dry Joint and Wet Joint systems.

This part is a direct replacement for MerCruiser part numbers 27-99757 and 8M0215011; Sierra 18-2909-9; GLM 32170; Mallory Marine 9-61421 and 9-61425; and others.

• Installation Location: Seals the connection between the exhaust manifold and the cylinder head.
• Gasket Material: Crafted from a durable, marine-grade composite material designed to withstand harsh marine environments.
• System Compatibility: Fits both Dry Joint and Wet Joint exhaust systems.

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 MerCruiser 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.

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

1 x Exhaust Manifold Gasket (27-99757/8M0215011)

Installation Guide

1. Ensure the engine is completely cool and disconnect the battery terminals as a safety precaution.
2. Drain the engine coolant from the block and exhaust manifold.
3. Carefully label and disconnect any wires, sensors, or hoses attached to the exhaust manifold.
4. Loosen and remove the bolts securing the manifold to the cylinder head, typically working from the outside bolts inward.
5. Gently tap the manifold with a rubber mallet to break the seal if it is stuck; do not pry between the mating surfaces.
6. Remove the old gasket and thoroughly clean all residual gasket material and carbon from both the cylinder head and manifold surfaces.
7. Ensure both mating surfaces are perfectly clean, dry, and flat before proceeding.
8. Position the new gasket, ensuring it aligns correctly with the bolt holes and exhaust ports.
9. Reinstall the exhaust manifold and hand-tighten the bolts.
10. Using a torque wrench, tighten the bolts to the manufacturer's specified torque sequence and values.
11. Reconnect all previously removed hoses, wires, and sensors.
12. Refill the cooling system, reconnect the battery, and start the engine, checking carefully for any exhaust or coolant leaks.

Troubleshooting & FAQ

Q: How do I confirm this gasket fits my specific MerCruiser V6 model?
A: Check your engine's model, year, and serial number against the "Compatible Engine Models" table. This gasket fits a wide range of MerCruiser V6 engines from 1983 to 2004, including 4.3L models. Verifying your existing part number against the OEM part number (27-99757) is the most reliable method.

Q: Is this gasket for a dry joint or wet joint exhaust system?
A: This gasket is versatile and compatible with both dry joint and wet joint exhaust systems for the specified MerCruiser V6 engines.

Q: What are the signs that my old exhaust manifold gasket is failing?
A: Common signs of a failing gasket include visible water leaks from the seal between the manifold and head, water entering the cylinders (which can cause hydrolock), engine overheating, poor engine performance, or an audible exhaust leak.

Q: OEM vs. Aftermarket?
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?

• 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.