Carburetor Mounting Gasket – Fits MerCruiser Rochester & MerCarb 2BBL (Replaces 27-8079821)

$3.75 $6.00

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Product Details

This Carburetor Mounting Gasket creates a crucial seal between the carburetor base and the intake manifold. It is designed to fit a wide range of MerCruiser 3.0L, 4.3L, 5.0L, 5.7L, and 6.2L inboard and sterndrive engines that utilize Rochester and MerCarb 2-barrel carburetors.

This part serves as a direct replacement for multiple OEM and aftermarket part numbers, ensuring broad compatibility for various engine models within the MerCruiser line.

Installs between the carburetor base and the intake manifold.
Engineered for gasoline marine environments.
Prevents vacuum leaks and ensures proper air-fuel mixture.

Part Number Matrix

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

Brand	Part Number
Mercury/MerCruiser	27-8079821
Mercury/MerCruiser	27-807982
Mercury/MerCruiser	27-807982B
Mercury/MerCruiser	27-70143
Mercury/MerCruiser	27-701431
Mercury/MerCruiser	27-2770143
Mercury/MerCruiser	27-2770143B1
Sierra	18-0994-9
Red Rhino	REC27-8079821

Engine & Model Compatibility

Confirm your engine model/year in the table below.

MerCruiser Applications: This gasket fits various sterndrive and inboard engines, primarily those equipped with 2-barrel carburetors from the late 1990s to current models.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.
MerCruiser	3.0L GM 181 I/L4	135	4-Stroke	0L097000 through current	27-8079821
MerCruiser	4.3L (GEN+) 2BBL GM 262 V-6	180	4-Stroke	1998 (0L010044–0M614999)	27-8079821
MerCruiser	4.3L CARB ALPHA/BRAVO	180	4-Stroke	0M615000–0W300012	27-8079821
MerCruiser	4.3LH (GEN+) 4BBL GM 262 V-6	180	4-Stroke	1998 (0L010044–0M614999)	27-8079821
MerCruiser	5.0L 2BBL GM 305 V-8	220	4-Stroke	1998–2001 (0L015751-0M599999)	27-8079821
MerCruiser	5.0L CARB ALPHA/BRAVO	220	4-Stroke	0M600000 through current	27-8079821
MerCruiser	5.0L MPI ALPHA/BRAVO	220	4-Stroke	All models	27-8079821
MerCruiser	5.7L 2BBL GM 350 V-8	250	4-Stroke	1996–2001	27-8079821
MerCruiser	5.7L CARB ALPHA/BRAVO	250	4-Stroke	0M600000 through current	27-8079821
MerCruiser	5.7L CARB MIE	250	4-Stroke	All models	27-8079821
MerCruiser	5.7L CARB SKI	250	4-Stroke	All models	27-8079821
MerCruiser	5.7L MPI MIE/HORIZON	250	4-Stroke	All models	27-8079821
MerCruiser	350 MAG MPI ALPHA/BRAVO	300	4-Stroke	All models	27-8079821
MerCruiser	350 MAG MPI MIE/HORIZON	300	4-Stroke	All models	27-8079821
MerCruiser	377 MAG MPI BRAVO	320	4-Stroke	All models	27-8079821
MerCruiser	6.2L MPI MIE/HORIZON	320	4-Stroke	All models	27-8079821
MerCruiser	MX 6.2L MPI BRAVO	320	4-Stroke	All models	27-8079821
MerCruiser	MX 6.2L MPI MIE/HORIZON	320	4-Stroke	All models	27-8079821
MerCruiser	3.0L TKS Plus	135	4-Stroke	1G404114 & Up	27-8079821
MerCruiser	350 (4BBL) Crate Engine	300	4-Stroke	All models	27-8079821
MerCruiser	383 MAG STROKER	350	4-Stroke	1G400000 & Up	27-8079821

Technical Specs

Product Type: Carburetor Mounting Gasket
Installation: Between carburetor base and intake manifold
Fuel Type: Gasoline
Material: Paper/Composite
Dimensions: 6.0" H x 7.5" W x 0.13" L

What’s in the Box

1 x Carburetor Mounting Gasket (27-8079821)

Installation Notes

Disconnect the battery and ensure the engine is cool before starting.
Shut off the fuel supply and place absorbent rags around the carburetor to catch any spillage.
Carefully disconnect fuel lines, throttle linkages, and any vacuum hoses connected to the carburetor. Label them to ensure correct reassembly.
Remove the mounting nuts or bolts securing the carburetor to the intake manifold.
Gently lift the carburetor off the manifold and set it aside. Remove and discard the old gasket.
Thoroughly clean both the carburetor's base and the intake manifold's mounting surface. Ensure they are completely free of old gasket material, sealant, and debris.
Position the new gasket onto the intake manifold, aligning it carefully with the mounting studs or bolt holes.
Lower the carburetor back onto the new gasket, ensuring it is seated correctly.
Tighten the mounting nuts or bolts in a crisscross pattern to the manufacturer's recommended torque specification to ensure an even seal. Do not overtighten.
Reconnect all fuel lines, linkages, and hoses.
Turn the fuel supply back on, reconnect the battery, and carefully check for any fuel or vacuum leaks before starting the engine.

Troubleshooting & FAQ

How do I know if my carburetor gasket is failing?

Common signs include a rough idle, engine stalling, vacuum leaks (often identifiable by a hissing sound near the carburetor base), reduced fuel economy, or visible fuel leaking around the carburetor.

Can this gasket be reused?

No. It is strongly recommended to use a new gasket every time the carburetor is removed. Reusing an old, compressed gasket can lead to improper sealing, causing vacuum or fuel leaks.

Does this gasket require any sealant?

Generally, this type of gasket is designed for a dry installation. Applying sealant can interfere with a proper seal or cause the gasket to degrade prematurely. Always consult your engine's service manual for specific recommendations.

What is the main difference between this gasket and an OEM part?

This aftermarket gasket is manufactured to meet or exceed OEM specifications for fit, material, and performance. It provides a reliable, long-lasting seal at a more competitive price point.

How often should this gasket be replaced?

The gasket should be replaced whenever the carburetor is removed for service or if symptoms of a leak appear. There is no fixed time-based replacement interval; its replacement is dictated by service needs.

Will this fit a 4-barrel carburetor?

No, this gasket is specifically designed for the base of MerCarb and Rochester 2-barrel (2BBL) carburetors. It will not fit 4-barrel models, which have a different bolt pattern and throttle bore layout.

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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