Mercury Power Head Gasket Set – Fits Mercury/Mariner 75-115 HP 4-Stroke (Replaces 8M0057763, 27-8M0057763)

$189.99

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Product Details

This complete Mercury Power Head Gasket Set provides all necessary gaskets for servicing the engine block assembly on Mercury and Mariner 75, 80, 90, 100, and 115 HP 4-Stroke outboards. It has also been verified for use in certain 150 HP 4-Stroke models (serial number 1B905505 and up).

It is a direct replacement for Mercury OEM part numbers 8M0057763 and 27-8M0057763, and interchanges with aftermarket part AM27-8M0057.

Complete kit for servicing the cylinder head, block, and related components.
Designed for use in gasoline outboard engines.
Installs within the engine block assembly.

Part Number Matrix

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

Brand	Part Number	Notes
Mercury	8M0057763	Primary OEM Number
Mercury	27-8M0057763	Alternative OEM Number
Aftermarket	AM27-8M0057	Interchange Part

Engine & Model Compatibility

Confirm your engine model/year in the table below.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Mercury	150 4-Stroke	150	4-Stroke	1B905505 & Up	8M0057763	Factory OEM part

Technical Specs

Product Type: Powerhead Gasket Set
Installation Location: Engine Block Assembly
Fuel Type: Gasoline
Packaged Dimensions: 64 cm × 37 cm × 3 cm (approx. 25.2 in × 14.6 in × 1.2 in)
Weight: 0.56 kg (1.23 lbs)
Warranty: 1-Year Manufacturer Warranty

What’s in the Box

1 x Powerhead Gasket Set (Replaces 8M0057763)

Installation Notes

For a successful installation, follow the OEM service manual for your specific engine model. A generic process is outlined below:

Disconnect the battery and all electrical connections to the engine.
Drain engine oil and coolant completely.
Remove the engine cowling and any interfering components like the flywheel cover or intake manifold.
Carefully disconnect all fuel lines, sensors, and linkages attached to the powerhead.
Systematically loosen and remove the powerhead mounting bolts in the sequence specified by the manufacturer.
Lift the powerhead from the midsection. This may require a lifting hoist due to its weight.
Remove the old gaskets and meticulously clean all mating surfaces. Ensure they are free of old gasket material, sealant, oil, and corrosion.
Position the new gaskets correctly. Do not use any sealant unless explicitly required by the service manual.
Carefully lower the powerhead back into position.
Install and torque all bolts to the manufacturer's specified values and sequence.
Reconnect all components in the reverse order of removal.
Refill engine oil and coolant, check for leaks, and test run the engine according to the service manual procedures.

Troubleshooting & FAQ

How can I confirm this set fits my engine if it's not a 150 HP model?

This set is widely specified for Mercury/Mariner 75, 80, 90, 100, and 115 HP 4-stroke outboards. The best way to confirm is to match your existing OEM part number to 8M0057763 or 27-8M0057763. If you cannot find your part number, consult your engine's service manual or contact us with your engine's serial number.

What are the signs of a failed powerhead gasket?

Common symptoms include milky or frothy engine oil (indicating water intrusion), loss of compression in one or more cylinders, engine overheating, reduced performance, or visible exhaust or water leaks between the cylinder head and engine block.

Does this kit include every gasket I might need for the job?

This is a comprehensive powerhead gasket set that includes all gaskets typically required for a cylinder head and block service. However, it is always best practice to visually compare the contents of the kit with the gaskets on your specific engine before beginning work.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 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

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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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