Reed Block Gasket – Fits Mercury/Mariner 200-300 HP 6-Cylinder 3L (Replaces 27-8141951)

$16.50

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Product Details

This Reed Block Gasket – Fits Mercury/Mariner 200-300 HP 6-Cylinder 3L (Replaces 27-8141951) is engineered for a precise fit on Mercury/Mariner 200-300 HP, 6-cylinder 3.0L engines with a 3.625" bore, covering models from 1994–2005.

It serves as a direct interchange for Mercury OEM part 27-8141951 and WSM aftermarket part 516-40.

Installation Method: Direct replacement
Origin: Manufactured in Italy by WSM
Material: High-quality gasket material for a reliable seal

Part Number Matrix

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

Brand	Part Number	Notes
Mercury	27-8141951	OEM Reference
WSM	516-40	Aftermarket Replacement

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This gasket is designed for specific Mercury and Mariner 6-cylinder 3.0L models as listed.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Mercury	3L	225	2-Stroke	1994–2001	27-8141951	6 Cylinder, 3.625" Bore
Mercury	3L EFI	225	2-Stroke	1995–2001	27-8141951	6 Cylinder, 3.625" Bore
Mercury	3L EFI	250	2-Stroke	1995–2001	27-8141951	6 Cylinder, 3.625" Bore
Mercury	3L Pro Max	300	2-Stroke	1998–2005	27-8141951	6 Cylinder, 3.625" Bore
Mercury	3L XB	250	2-Stroke	2000–2004	27-8141951	6 Cylinder, 3.625" Bore
Mercury	3L Optimax	200	2-Stroke	1997	27-8141951	6 Cylinder, 3.6265" Bore
Mercury	3L Carb Sea Pro	225	2-Stroke	1995–2001	27-8141951	6 Cylinder, 3L

Technical Specs

Product Type: Reed Block Gasket
Installation: Direct replacement
Material: High-quality gasket material
Dimensions: 0.2cm H x 30.0cm W x 46.0cm L
Manufacturing: Made in Italy (WSM)

What’s in the Box

1 x Reed Block Gasket (Replaces 27-8141951)

Installation Notes

Ensure the engine is off and the battery is disconnected.
Relieve any pressure from the fuel system.
Remove components obstructing access to the reed blocks, such as the airbox or carburetors.
Carefully unbolt and remove the reed block assembly from the engine crankcase.
Remove the old gasket. Thoroughly clean both mating surfaces to remove all old gasket material and debris. A plastic scraper and a suitable solvent can be used.
Position the new gasket correctly over the dowel pins or alignment holes.
Reinstall the reed block assembly, ensuring it is seated properly against the new gasket.
Tighten the mounting bolts in a crisscross pattern to the manufacturer's recommended torque specification to ensure an even seal.
Reassemble all components that were previously removed.
Reconnect the battery, check for any fuel or air leaks, and start the engine to test for proper operation.

Troubleshooting & FAQ

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

Common symptoms of a bad reed block gasket include a rough idle, difficulty starting, poor acceleration, backfiring through the intake, or a noticeable air leak sound from the engine block. A visual inspection may also reveal cracks or degradation of the old gasket.

Is any sealant required when installing this gasket?

Generally, high-quality gaskets like this one are designed to be installed dry on clean, flat surfaces. Applying sealant can sometimes cause the gasket to slip or extrude, leading to a poor seal. Always follow the engine manufacturer's service manual for specific recommendations.

Can I reuse my old reed block gasket?

No. Gaskets are single-use components that compress and conform to the mating surfaces. Once torqued and heat-cycled, they lose their ability to create a reliable seal if reused and should always be replaced.

What happens if I don't replace a bad gasket?

A leaking reed block gasket creates an unmetered air leak into the crankcase, which leans out the air-fuel mixture. This can lead to poor engine performance, increased internal temperatures, piston damage, and potentially catastrophic engine failure.

How can I confirm this part fits my engine?

Cross-reference your engine's model, horsepower, and year with the "Engine & Model Compatibility" table. Additionally, match the OEM part number (27-8141951) from your engine's service records or existing part with the numbers in the "Part Number Matrix".

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.

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