Mercury Gasket Set – Fits Mercury/Mariner 30/40 HP 2-Cylinder (Replaces 27-822420A94)

$34.50

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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 powerhead Mercury Gasket Set is engineered for Mercury/Mariner 30/40 HP, 2-stroke, 2-cylinder engines manufactured between 1994 and 2007. It provides the essential seals needed for a complete engine overhaul, ensuring a reliable fit and restoring peak performance.

This kit serves as a direct replacement for Mercury OEM part number 27-822420A94 and is interchangeable with WSM part 500-199.

Product Type: Powerhead Gasket Set
Primary Use: Complete engine overhaul and rebuild
Fuel System: Designed for gasoline engines

Part Number Matrix

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

Brand	Part Number
Mercury	27-822420A94
WSM	500-199

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This gasket set is designed for specific 2-cylinder Mercury and Mariner outboards.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.
Mercury	2 Cylinder 2.992 Bore	30	2-Stroke	1994–2007	27-822420A94
Mercury	2 Cylinder 2.992 Bore	40	2-Stroke	1994–2007	27-822420A94
Mercury	2 Cylinder	40	2-Stroke	2014	27-822420A94
Mariner	2 Cylinder	30	2-Stroke	1994–2007	27-822420A94
Mariner	2 Cylinder	40	2-Stroke	1994–2007	27-822420A94

Please also verify your engine’s serial number against the ranges below.

Engine Series	Serial Number Range
30 (2 CYL.)	9854537 THRU 0P016999
30 (2 CYL.)	0G055314 THRU 0G760299
30 (2 CYL.)	0G760300 THRU 0T979999
30 (2 CYL.)	0P017000 THRU 0P325499
30 (2 CYL.)	0P325500 & Up
30 (2 CYL.)	0T980000 THRU 0T999999
30 (2 CYL.)	1B000001 & Up
40 (2 CYL.)	9854537 THRU 0P016999
40 (2 CYL.)	0G055314 THRU 0G760299
40 (2 CYL.)	0G760300 THRU 0T979999
40 (2 CYL.)	0P017000 THRU 0P325499
40 (2 CYL.)	0P325500 & Up
40 (2 CYL.)	0T980000 THRU 0T999999
40 (2 CYL.)	1B000001 & Up

Technical Specs

Product Type: Powerhead Gasket Set
Installation: Engine Overhaul
Fuel Type: Gasoline
Housing Material: Various (Gasket Materials)
Product Dimensions: 29.0" H × 19.0" W × 0.4" L
Weight: 0.23 kg (0.5 lb)

Installation Notes

General guide for gasket set installation during a powerhead overhaul. Always refer to your engine’s specific service manual for detailed instructions and torque specifications.

Disconnect the negative battery cable and secure all fuel lines. Drain engine oil and coolant completely.
Carefully disassemble the powerhead, labeling all components and fasteners for organized reassembly.
Thoroughly remove all old gasket material from the mating surfaces. Use a plastic scraper and an appropriate solvent to avoid scratching the metal.
Ensure surfaces are perfectly clean, dry, and free of oil, grease, or debris before placing the new gaskets.
Position the new gaskets correctly. Do not use any sealant unless explicitly required by the service manual.
Reassemble the powerhead, tightening all bolts in the sequence and to the torque values specified in your manual.
Reconnect all electrical and fuel connections. Refill the engine with fresh oil and coolant.
Before starting the engine, check for any leaks. Run the engine at idle and re-check for leaks.

Troubleshooting & FAQ

How do I confirm this gasket set is correct for my engine?

First, match your engine's brand, model, HP, and year to the compatibility table. Second, and most importantly, verify your engine's serial number falls within one of the listed ranges. If either does not match, this part is likely incorrect.

What are the common signs of a failed head gasket?

Symptoms include engine overheating, loss of power, white smoke from the exhaust (burning coolant), milky or foamy oil, and visible coolant or oil leaks around the powerhead seam. A compression test is often the best diagnostic step.

Is this a complete kit for a full powerhead rebuild?

This is a powerhead gasket set, which includes the primary seals for the engine block and cylinder head. It may not include every o-ring or seal for auxiliary components. Please review product photos to see all included items.

Why choose an aftermarket gasket set over OEM?

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.

What is the shipping speed and cost?

We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

What is the warranty and return policy?

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

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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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