Exhaust Manifold Gasket – Fits Mercury/Mercruiser 120 4-Cylinder (Replaces 27-52546, 27-32816)

$19.40 $31.00

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Exhaust Manifold Gasket – Fits Mercury/Mercruiser 120 4-Cylinder (Replaces 27-52546, 27-32816) 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 high-quality Exhaust Manifold Gasket is designed for a precise fit on Mercury/Mercruiser 4-cylinder GM 153 I/L4 engines, specifically the 120 HP models manufactured between 1963 and 1982. It creates a reliable seal between the exhaust manifold and cylinder head to prevent exhaust leaks.

It serves as a direct replacement for multiple OEM and aftermarket part numbers, including Mercury/Mercruiser 27-32816/27-52546, Sierra 18-2896-1, GLM 31550, and others.

Installation Location: Mounts between the exhaust manifold and the cylinder head.
Engine Environment: Designed for use in gasoline marine engines.
Compatibility Note: Especially suited for early models (110/120 HP) where the carburetor linkage mounts to the rear of the engine.

Part Number Matrix

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

Brand	Part Number
Mercury/Mercruiser	27-32816
Mercury/Mercruiser	27-52546
Sierra	18-2896-1
Barr	MC47-27-52546
GLM	31550
Mallory	9-61426
OMC Stern Drive	311068
Osco	CY4-GH

Engine & Model Compatibility

Confirm your engine model and year in the table below to ensure correct fitment.

For Mercury/Mercruiser owners: This part is broadly compatible with 110 HP and 120 HP GM 153 I/L4 engines from 1963–1982. Please check your serial number against the ranges provided for a perfect match.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Mercury/Mercruiser	120 GM 153 I/L4	120	4-Stroke	1964–1972	27-52546	Serial #1666601-3377340
Mercury/Mercruiser	120 GM 153 I/L4	120	4-Stroke	1972–1978	27-52546	Serial #3377341-5192048
Mercury/Mercruiser	120 GM 153 I/L4	120	4-Stroke	1979–1982	27-52546	Serial #5192049-6229717
Mercury/Mercruiser	110	110	4-Stroke	1963–1982	27-52546	For early models where carb linkage mounts to rear

Technical Specs

Product Type: Exhaust Manifold Gasket
Installation: Between exhaust manifold and cylinder head
Fuel Type: Gasoline
Dimensions: 53.0 × 12.5 × 1.0 inches (1346 × 318 × 25 mm)
Weight: 0.13 lbs (0.059 kg)
Package Quantity: 1
Warranty: Varies by brand: Limited lifetime (Sierra), None (OEM Mercury)
Fits With: MC-1-63122 manifold
Compatibility Notes: Used with early models 110/120 where the carb linkage mounts to the rear of the engine

What’s in the Box

1 × Exhaust Manifold Gasket (Replaces 27-52546)

Installation Notes

Safety First: Disconnect the battery and allow the engine to cool completely before starting.
Drain Coolant: Drain the engine coolant from the block and manifold to a level below the gasket surface.
Remove Components: Detach any hoses, wires, or linkages connected to the exhaust manifold.
Unbolt Manifold: Carefully remove the bolts securing the exhaust manifold to the cylinder head.
Clean Surfaces: Thoroughly clean both the cylinder head and manifold mating surfaces. Remove all old gasket material and corrosion.
Position Gasket: Place the new gasket into position, ensuring it aligns correctly with all bolt holes and ports.
Reinstall Manifold: Reattach the exhaust manifold and tighten the bolts in the sequence and to the torque specifications recommended by the manufacturer.
Final Connections: Reconnect all hoses, wires, and linkages. Refill the cooling system.
Check for Leaks: Start the engine and carefully check for any exhaust or coolant leaks around the gasket area.

Troubleshooting & FAQ

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

Common signs of a bad gasket include a ticking or hissing sound from the engine bay (especially when cold), a noticeable smell of exhaust fumes, decreased engine performance or fuel efficiency, and visible soot or black marks around the manifold-head joint.

Will this fit my Mercruiser 120 engine if the serial number is not listed?

This gasket fits most Mercruiser 120 HP models from 1963-1982. The serial numbers provide precise confirmation. If your number is outside these ranges but the model year matches, visually compare your old gasket to the product images to ensure a match, especially noting the port and bolt hole pattern.

Do I need to use sealant with this gasket?

Generally, this type of gasket is designed for dry installation. However, always consult your engine's service manual. Some mechanics apply a very thin layer of high-temperature copper sealant as a best practice, but it is not typically required.

What’s the difference between this aftermarket gasket and the OEM part?

This aftermarket gasket is engineered to meet or exceed OEM specifications for fit, form, and function. While it is not an OEM part, it is made from comparable, high-quality materials in an ISO 9002 certified facility to ensure reliability and performance at a better value.

How fast do you ship and what is the cost?

We ship worldwide quickly—typical transit is 5–15 days for most regions. Standard shipping is free. Expedited shipping options, if available for your location, will be presented at checkout.

What is the warranty and return policy?

This part is covered by a 1-year warranty against manufacturing defects under normal marine use. Should an issue arise, contact our support team with your order number. Returns are accepted within our standard return window for items that are unused and in their original packaging. Please see our full policy page or contact us for instructions.

Safety & Important Info

Verify images and specifications against your original part before purchasing. If anything differs—even if your model appears on a compatibility list—do not install.
This is an aftermarket replacement part, not an original equipment manufacturer (OEM) component.
Professional installation is strongly recommended for safety, performance, and to prevent engine damage.

About Sea Sierra

Pro-Grade Standards: We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world saltwater and freshwater conditions.
Fast Global Fulfillment: We provide free standard delivery to most regions worldwide, with typical transit times of 5–15 days from our closest distribution center.
Manufacturer-Direct Value: By working directly with manufacturers, we offer fair, transparent pricing without compromising on materials or quality control.

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