Transfer Port Gasket – Fits Mercury/Mariner 90-140 HP Inline 6-Cylinder (Replaces 27-856730)
Transfer Port Gasket – Fits Mercury/Mariner 90-140 HP Inline 6-Cylinder (Replaces 27-856730) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Transfer Port Gasket – Fits Mercury/Mariner 90-140 HP Inline 6-Cyli...
Product Details
This is a high-quality aftermarket Transfer Port Gasket – Fits Mercury/Mariner 90-140 HP Inline 6-Cylinder (Replaces 27-856730). It is designed for a precise fit on Mercury and Mariner 90 HP, 115 HP, and 140 HP inline 6-cylinder outboard engines, providing a reliable seal for the transfer port cover.
This component serves as a direct replacement for Mercury OEM part numbers 27-856730 and the superseded part 27-85653.
- Installs as a direct OEM-fit replacement.
- Engineered for gasoline-powered marine environments.
- Corrosion-resistant materials ensure longevity and a durable seal.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Mercury | 27-85653 | Superseded by 27-856730 |
| Mercury | 27-856730 | Current Part Number |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Mercury and Mariner engines, this gasket fits the inline 6-cylinder models listed. Please verify your specific engine details and OEM part number before ordering.
| Brand | Model | Rated HP | OEM Part No. | Notes |
|---|---|---|---|---|
| Mercury/Mariner | Inline 6-Cylinder | 90 | 27-856730 | Supersedes 27-85653 |
| Mercury/Mariner | Inline 6-Cylinder | 115 | 27-856730 | Supersedes 27-85653 |
| Mercury/Mariner | Inline 6-Cylinder | 140 | 27-856730 | Supersedes 27-85653 |
Technical Specs
- Product Type
- Transfer Port Cover Gasket
- Installation
- Direct OEM replacement
- Fuel Type
- Gasoline
- Dimensions
- 22.0" x 7.0" x 1.13"
- Weight
- 0.06 lbs (0.027 kg)
What’s in the Box
- 1 x Gasket (27-856730)
Installation Notes
- Ensure the engine is off and cool, and disconnect the battery for safety.
- Locate and remove the fasteners for the transfer port cover.
- Carefully detach the cover and remove the old gasket. Thoroughly clean any old gasket material or residue from both the cover and the engine block mating surfaces.
- Position the new gasket correctly onto the engine block, aligning it with the bolt holes.
- Re-install the transfer port cover, ensuring it is seated properly over the new gasket.
- Tighten the fasteners in a star or crisscross pattern to the manufacturer's recommended torque specifications to ensure even pressure.
- Reconnect the battery. After starting the engine, check for any air or fuel leaks around the cover.
Troubleshooting & FAQ
How do I know if this gasket fits my engine?
This gasket is specifically for Mercury/Mariner 90, 115, and 140 HP inline 6-cylinder outboards. The best way to confirm fitment is to match your existing part number to 27-856730 or its superseded number, 27-85653. Also, review the compatibility table on this page.
What are the symptoms of a failing transfer port gasket?
A failed gasket can cause a vacuum leak, leading to symptoms like a rough or unstable idle, difficulty starting, reduced engine power, hesitation during acceleration, and sometimes an audible whistling or sucking sound from the engine compartment.
Do I need to use sealant with this gasket?
In most cases, this gasket is designed to be installed dry. Applying sealant can sometimes interfere with a proper seal unless specified by the engine manufacturer. Always refer to your engine's official service manual for the most accurate installation procedure.
What is the difference between part number 27-856730 and 27-85653?
Part number 27-856730 is the current, updated OEM part that officially supersedes the older number, 27-85653. They are functionally identical and interchangeable for all listed applications.
Why is it important to replace a bad gasket?
A bad gasket creates an air leak, which leans out the air-fuel mixture. This can lead to poor performance, increased engine temperatures, and potential long-term engine damage if left unaddressed.
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.
Payment & Security
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