Gasket Guide Plate – Fits Mercury/Mercruiser 9.9–20 HP 2-Cylinder Engines (27-8M0135806)

$3.75 $6.00

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Product Details

This aftermarket Gasket Guide Plate is a crucial engine service component designed for a precise fit on Mercury and Mariner 9.9–20 HP, 4-stroke, 2-cylinder EFI engines manufactured from 2011 and newer. It ensures a proper seal, preventing leaks and maintaining engine integrity.

It serves as a direct replacement for Mercury part number 27-8M0135806 and the equivalent Quicksilver part 8M0135806.

Designed for use with gasoline engines.
Replaces a critical engine service component to restore sealing.
Engineered to meet OEM specifications for fit and function.

Part Number Matrix

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

Brand	Part Number
Mercury	27-8M0135806
Quicksilver	8M0135806

Engine & Model Compatibility

Confirm your engine model/year in the table below.

This part is confirmed to fit the following Mercury and Mariner engine models.

Brand	Model	Rated HP	Stroke	Years	OEM Part No.	Notes
Mercury	9.9 HP EFI 2 CYL	9.9	4-Stroke	2011 and up (1R008146 & Up)	27-8M0135806
Mercury	10 HP EFI 2 CYL	10	4-Stroke	2011 and up (0R833820 & Up)	27-8M0135806
Mercury	15 HP EFI 2 CYL	15	4-Stroke	2011 and up (0R833820 & Up)	27-8M0135806
Mercury	15 HP EFI SeaPro 2 CYL	15	4-Stroke	2011 and up (0R833820 & Up)	27-8M0135806	Commercial variant
Mercury	20 HP EFI 2 CYL	20	4-Stroke	2011 and up (0R833820 & Up)	27-8M0135806

Technical Specs

Product Type: Gasket (Guide Plate)
Installation: Engine service component
Fuel Type: Gasoline
Dimensions: 1.0" H x 10.0" W x 10.0" L
Weight: 0.01 lb (0.005 kg)
Warranty: Standard manufacturer warranty
GTIN: 745061029576

What’s in the Box

1 x Gasket Guide Plate (27-8M0135806)

Installation Notes

Ensure the engine is cool and disconnect the battery for safety.
Access the guide plate assembly, removing any covers or components that are in the way.
Carefully remove the old gasket. Clean both mating surfaces meticulously to remove all old gasket material and residue.
Position the new gasket correctly. Ensure it sits flat and is properly aligned with all bolt holes and passages.
Reinstall the guide plate and tighten the bolts in the sequence and to the torque values specified by the manufacturer.
Reconnect the battery, start the engine, and carefully inspect for any leaks.

Troubleshooting & FAQ

How do I know if this gasket fits my specific engine model?

Verify your engine model and year against the compatibility table. This gasket fits select Mercury/Mariner 9.9–20 HP 2-cylinder 4-stroke engines from 2011 and newer, starting from serial number 0R833820 (or 1R008146 for 9.9 HP models).

What are the signs of a failing guide plate gasket?

Common signs include oil or coolant leaks around the guide plate area, engine overheating, or poor performance due to loss of compression or fluid contamination.

Is this part the same as Quicksilver 8M0135806?

Yes, this part is a direct cross-reference. Mercury and Quicksilver often use identical part numbers for the same component, as Quicksilver is a brand of Mercury Marine.

Where is this gasket typically installed?

This gasket is an internal engine service component that creates a seal for the guide plate. Its exact location is specific to the engine's design, but it is critical for preventing internal and external fluid leaks.

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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