Reed Block Gasket – Fits Mercury & Mariner 15-25HP Outboards (Replaces 27-414181, 27-41418, 27-85979)

$4.40 $7.00

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Product Details

This high-quality Reed Block Gasket – Fits Mercury & Mariner 15-25HP Outboards (Replaces 27-414181, 27-41418, 27-85979) ensures a proper seal between the carburetor and reed block. It is designed for a wide range of Mercury & Mariner 15–25 HP, 2-stroke outboard models from the late 1970s through the late 1980s, including SEA PRO, MARATHON, and SUPER 15 series.

This part is a direct replacement for Mercury part numbers 27-414181, 27-41418, 27-85979 and aftermarket equivalent GLM 36760.

Installs at the outboard carburetor-to-reed block interface.
Engineered for use with gasoline fuel systems.
Located between the reed block and carburetor adaptor plate.

Part Number Matrix

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

Brand	Part Number
Mercury	27-414181
Mercury	27-41418
Mercury	27-85979
GLM	36760

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury Outboards: This part fits various 15, 18, 20, and 25 HP models from 1980–1987, including MARATHON, SEA PRO, and JET series.

For Mariner Outboards: Compatible with select 20 and 25 HP models from 1977 and the mid-1980s.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.
Mercury	18 [E]	18	2-Stroke	1980–1984	27-414181
Mercury	18 [EL]	18	2-Stroke	1980–1984	27-414181
Mercury	18 [M]	18	2-Stroke	1980–1985	27-414181
Mercury	18 [ML]	18	2-Stroke	1980–1985	27-414181
Mercury	20 [E]	20	2-Stroke	1987	27-414181
Mercury	20 [EL]	20	2-Stroke	1987	27-414181
Mercury	20 [M]	20	2-Stroke	1986–1987	27-414181
Mercury	20 [ML]	20	2-Stroke	1986–1987	27-414181
Mercury	20 [ML/ALT]	20	2-Stroke	1986	27-414181
Mercury	20 JET	20	2-Stroke	Various	27-414181
Mercury	25 [E]	25	2-Stroke	1980–1987	27-414181
Mercury	25 [EH]	25	2-Stroke	1985–1987	27-414181
Mercury	25 [EL]	25	2-Stroke	1980–1987	27-414181
Mercury	25 [ELH]	25	2-Stroke	1985–1987	27-414181
Mercury	25 [M]	25	2-Stroke	1980–1987	27-414181
Mercury	25 [ML]	25	2-Stroke	1980–1987	27-414181
Mercury	25 MARATHON, SUPER 15	25	2-Stroke	Various	27-414181
Mercury	25 SEA PRO, SUPER 15	25	2-Stroke	Various	27-414181
Mercury	25 XS	25	2-Stroke	Various	27-414181
Mercury	15 MARATHON	15	2-Stroke	Various	27-414181
Mercury	15 MARATHON XD	15	2-Stroke	Various	27-414181
Mercury	15 SEA PRO	15	2-Stroke	Various	27-414181
Mercury	15 SEA PRO (XD)	15	2-Stroke	Various	27-414181
Mariner	20 [E]	20	2-Stroke	1984, 1987	27-414181
Mariner	20 [EL]	20	2-Stroke	1984–1985, 1987	27-414181
Mariner	20 [M]	20	2-Stroke	1977, 1984–1986	27-414181
Mariner	20 [ML]	20	2-Stroke	1984–1987	27-414181
Mariner	25 [E]	25	2-Stroke	1985	27-414181
Mariner	25 [EH]	25	2-Stroke	1987	27-414181
Mariner	25 [EL]	25	2-Stroke	1985, 1987	27-414181
Mariner	25 [ELH]	25	2-Stroke	1987	27-414181
Mariner	25 [M]	25	2-Stroke	1985–1987	27-414181
Mariner	25 [ML]	25	2-Stroke	1985–1987	27-414181

Technical Specs

Product Type: Reed Block Gasket
Installation: Outboard carburetor-to-reed block interface
Fuel Type: Gasoline
Housing Material: Gasket Material (paper/composite)
Dimensions: 17.0" L x 10.5" W x 0.1" H
Weight: 0.02 lb (0.009 kg)
Other Technical Attributes: Located between reed block and carburetor adaptor plate

What’s in the Box

1 x Gasket (Replaces 27-414181)

Installation Notes

Disconnect the battery and ensure the engine is off and cool.
Shut off the fuel supply and safely disconnect the fuel line from the carburetor.
Carefully remove the airbox/silencer cover to access the carburetor.
Unbolt and remove the carburetor from the reed block assembly.
Remove the old gasket and thoroughly clean both mating surfaces of any residue or debris. Use a plastic scraper to avoid gouging the metal.
Position the new gasket onto the reed block, ensuring all bolt holes align correctly.
Reinstall the carburetor, tightening the bolts to the manufacturer's specified torque in a crossing pattern.
Reconnect the fuel line, re-attach the airbox cover, and reconnect the battery.
Turn on the fuel supply, prime the system, and check for any leaks before starting the engine.

Troubleshooting & FAQ

How do I know if my reed block gasket is failing?

Common signs include a rough idle, difficulty starting, poor acceleration, stalling at low speeds, or visible fuel/air leaks around the carburetor and reed block interface.

Will this gasket fit my engine if it's not on the compatibility list?

We strongly recommend only using this part for the models listed. Using it on an incompatible engine may lead to vacuum leaks, poor performance, or potential engine damage. Always verify your model and part number.

Is any sealant required during installation?

Generally, this type of gasket is designed to be installed dry. Applying sealants can sometimes cause the gasket to slip, squeeze into the intake path, or break down prematurely. Always consult your engine's service manual for specific recommendations.

What is the purpose of this gasket?

It creates an essential airtight seal between the carburetor and the reed block assembly. This prevents vacuum leaks, ensuring the correct air-fuel mixture for proper engine performance, idling, and acceleration.

How often should this gasket be replaced?

The gasket should be replaced anytime the carburetor is removed from the reed block for service, cleaning, or replacement. This ensures a perfect, leak-free seal upon reassembly.

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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