Exhaust Plate Gasket – Fits Mercury Marine 135-175 HP (Replaces 27-997761)

$15.15 $24.00

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Product Details

This aftermarket Exhaust Plate Gasket provides a reliable seal for the exhaust plate on Mercury Marine 135-175 HP V6 2-stroke outboard engines manufactured between 1976 and 1985. It's engineered to meet original equipment specifications for a precise fit and optimal performance.

This part is a direct replacement for Mercury OEM part numbers 27-997761, 27-99776, and 27-96440.

Designed for direct, hassle-free installation.
Made from durable materials for a long-lasting seal in marine environments.
Restores a proper seal to prevent exhaust and water leaks.

Part Number Matrix

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

Brand	Part Number	Superseded By	Notes
Mercury	27-99776	27-997761	Superseded Part
Mercury	27-96440	27-997761	Superseded Part
Mercury	27-997761	—	Current OEM Number

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For use with the following Mercury Marine V6 outboard engines:

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Mercury	V-135	135	2-Stroke	1976–1985	27-997761	Supersedes 99776, 96440
Mercury	V-150	150	2-Stroke	1976–1985	27-997761	Supersedes 99776, 96440
Mercury	V-150 Magnum	150	2-Stroke	1978–1985	27-997761	Supersedes 99776, 96440
Mercury	V-150 Marathon	150	2-Stroke	1978–1985	27-997761	Supersedes 99776, 96440
Mercury	V-150 Work	150	2-Stroke	1978–1985	27-997761	Supersedes 99776, 96440
Mercury	V-1500	150	2-Stroke	1978–1985	27-997761	Supersedes 99776, 96440
Mercury	V-150-XR-2	150	2-Stroke	1978–1985	27-997761	Supersedes 99776, 96440
Mercury	V-175	175	2-Stroke	1976–1988	27-997761	Supersedes 99776, 96440

Technical Specs

Product Type: Exhaust Plate Gasket
Application: Marine outboard engines
Fitment: Mercury Marine V6 outboard exhaust plate
Installation: Direct replacement
Product Dimensions: 13.0" L x 10.0" W x 1.25" H
Replaces OEM Part Number: 27-997761
Supersedes: 27-99776, 27-96440

What’s in the Box

1 x Exhaust Plate Gasket (Replaces 27-997761, 27-99776, 27-96440)

Installation Notes

Ensure the engine is off and cool to the touch before beginning. Disconnect the battery for safety.
Access and carefully remove the exhaust plate cover and its mounting hardware.
Remove the old, worn-out gasket. Take note of its position and orientation.
Thoroughly clean both mating surfaces. All traces of old gasket material, sealant, and corrosion must be removed for a proper seal.
Position the new gasket correctly onto the clean surface.
Reinstall the exhaust plate cover. Tighten the bolts in the sequence and to the torque value specified in your engine's service manual.
Reconnect the battery, start the engine, and carefully inspect for any exhaust or water leaks around the newly sealed area.

Troubleshooting & FAQ

How do I know if my exhaust plate gasket is failing?

Common signs of a failed exhaust plate gasket include engine overheating, water intrusion into the cylinders, loss of performance, or visible exhaust/water leaks from the joint between the engine block and the exhaust plate.

Can I reuse my old gasket?

No. Gaskets are single-use components designed to compress and create a seal. Once compressed and heat-cycled, an old gasket will not provide a reliable seal and will likely cause leaks.

Is any special sealant required for installation?

Typically, this type of gasket is designed to be installed dry. However, it is essential to consult your specific engine's service manual, as some applications may have unique requirements.

What happens if I don't replace a leaking gasket?

Ignoring a leaking exhaust plate gasket can lead to serious engine damage, including overheating, corrosion of internal components, and catastrophic failure due to water entering the cylinders.

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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