Mercury Marine 27-96278 Gasket – Fits Mercury/Mariner Outboards (Replaces 96278)

$6.64 $10.00

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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 replacement Mercury Marine 27-96278 Gasket is a two-piece cylinder cover gasket designed for a range of V6 Mercury and Mariner 2-stroke outboards from the 1980s and 1990s, specifically fitting 135, 150, 175, and 200 HP models.

It is a direct replacement for Mercury Marine part numbers 27-96278 and 96278.

Engineered for OEM replacement fit and function.
Features a 2-piece design for easier installation.
Designed for use in gasoline marine engines.

Part Number Matrix

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

Brand	Part Number
Mercury Marine	27-96278
Mercury	96278

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury and Mariner models, fitment is often determined by serial number range. Please verify your engine's serial number falls within the specified range.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.
Mercury	V-135	135	2-Stroke	0A904646-0C100860	27-96278
Mercury	V-150	150	2-Stroke	4868998-0A904645	27-96278
Mercury	V-150	150	2-Stroke	5600162-0A904645	27-96278
Mercury	V-150	150	2-Stroke	0A904646-0C100860	27-96278
Mercury	V-150 Magnum	150	2-Stroke	5600162-0A904645	27-96278
Mercury	V-150 Marathon	150	2-Stroke	5600162-0A904645	27-96278
Mercury	V-150 Work	150	2-Stroke	4868998-0A904645	27-96278
Mercury	V-1500	150	2-Stroke	4868998-0A904645	27-96278
Mercury	V-1500	150	2-Stroke	5600162-0A904645	27-96278
Mercury	V-150-XR-2	150	2-Stroke	4868998-0A904645	27-96278
Mercury	V-175	175	2-Stroke	4301235-0C100860	27-96278
Mercury	V-175	175	2-Stroke	8058870 & Up	27-96278
Mercury	V-200	200	2-Stroke	5624878-0C100860	27-96278
Mercury	MERC FORMULA I (2L EFI)		2-Stroke	82E606-86G640	27-96278
Mercury	MERC MOD-VP		2-Stroke	0B290000 & Up	27-96278
Mercury	MERC MOD-VP		2-Stroke	83B807 & Up	27-96278
Mercury	MERC/MAR 2.4L (EFI)		2-Stroke	0A168043 & Below	27-96278
Mercury	MERC/MAR 2.4L (EFI)		2-Stroke	0A168044-0B290009	27-96278

Technical Specs

Product Type: Cylinder Cover Gasket (2-Piece Design)
Installation: OEM Replacement
Fuel Type: Gasoline
Housing Material: Gasket Material
Dimensions: 7.0" H x 22.0" W x 0.25" L

What’s in the Box

1 x Gasket Cylinder Cover (27-96278)

Installation Notes

Disconnect the battery and ensure the engine is cool.
Drain the cooling system as required by your service manual.
Carefully remove the cylinder cover and associated components to access the old gasket.
Thoroughly clean the mating surfaces of both the engine block and the cover. Ensure they are free of old gasket material, sealant, oil, and debris.
Position the new two-piece gasket correctly on the engine block. Verify alignment with all bolt holes and passages.
Reinstall the cylinder cover. Tighten the bolts in the sequence and to the torque specifications recommended by the manufacturer.
Reconnect any components that were removed. Refill the cooling system.
Reconnect the battery. Start the engine and check for any leaks around the gasket area.

Troubleshooting & FAQ

How do I confirm this gasket fits my specific engine?

The most reliable method is to check your engine's serial number against the ranges listed in the compatibility table. If your serial number is not listed, this part may not fit.

What are the signs of a failing cylinder cover gasket?

Common symptoms include water in the cylinders, engine overheating, a visible leak of water or exhaust from the cover area, and loss of compression or poor engine performance.

Is this a single gasket or a set?

This is a 2-piece gasket set intended to replace the original single part.

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

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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