Reed Block Gasket – Fits Mercury/Mariner 75-125 HP Outboards (Replaces 27-139376)

Product Details

This is a high-quality aftermarket Reed Block Gasket – Fits Mercury/Mariner 75-125 HP Outboards (Replaces 27-139376), designed for various 2-stroke inline 3 & 4-cylinder engines from the 1990s through the mid-2000s. It ensures a precise seal between the carburetor throat and the reed block, which is critical for preventing air leaks and maintaining engine performance.

It serves as a direct replacement for Mercury/Quicksilver part numbers 27-139376, 139376, 27-139374, 139374, 27-139372, 139372, 27-13937, 13937, and Sierra PM-1473.

• Installation: Mounts directly between the carburetor throat and the reed block assembly.
• Material: Constructed from a durable, fuel-resistant fiber composite to withstand gasoline and ethanol blends.
• Design: Features a precision-milled port design that is narrow in the center and flares to twin triangles at each end for optimal airflow.

Part Number Matrix

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

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Mercury and Mariner outboards, model compatibility is often determined by serial number ranges in addition to horsepower and year. Please verify your engine's serial number falls within the specified range.

Technical Specs

Product Type

Reed Block/Carburetor Gasket

Installation

Fits between carburetor throat and reed block

Fuel Type

Compatible with gasoline, including ethanol blends

Connection

4-bolt pattern

Housing Material

Fuel-resistant fiber composite

Housing Color

Dark green

Dimensions

6.0" H x 7.13" W x 1.03" L

Weight

0.02 lbs (0.009 kg)

Other Technical Attributes

Precision-milled port design: narrow in center, flaring to twin triangles at each end

What’s in the Box

• 1 x Reed Block Gasket (27-139376)

Installation Notes

1. Ensure the engine is off and the battery is disconnected. Safely relieve any pressure from the fuel system.
2. Carefully detach the fuel lines and remove the carburetor assembly from the engine.
3. Remove the old, worn reed block gasket. Take care not to drop any debris into the engine's intake ports.
4. Thoroughly clean both the carburetor and reed block mating surfaces. All old gasket material and residue must be removed to ensure a perfect seal.
5. Position the new gasket, aligning it with the bolt holes and intake ports.
6. Reinstall the carburetor, tightening the bolts in a star or cross pattern to the manufacturer's recommended torque specification.
7. Reconnect the fuel lines, then reconnect the battery. Prime the fuel system and check for any leaks before starting the engine.

Troubleshooting & FAQ

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.