Upper Base Gasket - Fits Force 75-120 HP (Replaces 27-826549)
Upper Base Gasket - Fits Force 75-120 HP (Replaces 27-826549) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Upper Base Gasket - Fits Force 75-120 HP (Replaces 27-826549)
Product Details
This is a high-quality aftermarket Upper Base Gasket designed for Force outboard engines, including 75, 90, and 120 HP 3-4 cylinder models manufactured between 1995 and 1999. It ensures a precise seal between the engine block and the cylinder head.
It is a direct replacement for WSM part number 510-57 and Sierra part number 18-2922, cross-referencing to OEM part 27-826549.
- Installation Location: Seals the joint between the engine block and cylinder head.
- Engine Fuel Type: Designed for gasoline outboard engines.
- Key Component: Ensures proper compression and prevents fluid leaks.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number |
|---|---|
| OEM | 27-826549 |
| WSM | 510-57 |
| Sierra | 18-2922 |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure accurate fitment.
For Force/Chrysler Engines: Please verify your model, horsepower, and year range against this compatibility list.
| Brand | Model | Rated HP | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|
| Force | 3 Cyl 3.375 Bore | 90 | 1995 | 27-826549 | Upper gasket |
| Force | 3 Cyl 3.375 Bore Top Guided | 75 | 1999 | 27-826549 | Upper gasket |
| Force | 3 Cyl 3.375 Bore Top Guided | 90 | 1996–1999 | 27-826549 | Upper gasket |
| Force | 4 Cyl 3.375 Bore | 120 | 1995 | 27-826549 | Upper gasket |
| Force | 4 Cyl 3.375 Bore Top Guided | 120 | 1996–1999 | 27-826549 | Upper gasket |
| Force | 90 HP | 90 | 1996–1997 | 27-826549 | Upper gasket |
| Force | 120 HP | 120 | 1996–1997 | 27-826549 | Upper gasket |
| Force | 120 HP | 120 | 1998–1999 | 27-826549 | Upper gasket |
| Force | 75/90 | 75 | 1999 | 27-826549 | Upper gasket |
Technical Specs
- Product Type
- Upper Base Gasket
- Installation
- Engine Block to Cylinder Head
- Material
- Gasket Material (Composite)
- Position
- Upper base gasket position
- Fuel Type
- Gasoline
- Dimensions
- 23.0 cm L x 20.3 cm W x 0.3 cm H
- Warranty
- No warranty (OEM part policy)
What’s in the Box
- 1 x Upper Base Gasket (replaces 27-826549)
Installation Notes
For a successful installation, follow these general steps. Always refer to your engine's specific service manual for detailed procedures and torque specifications.
- Disconnect the battery and drain the engine's cooling system.
- Carefully detach all components connected to the cylinder head, such as intake/exhaust manifolds, wiring, and fuel lines.
- Remove the cylinder head bolts in the sequence specified by the manufacturer.
- Lift the cylinder head off the engine block and remove the old base gasket.
- Thoroughly clean both the cylinder head and engine block surfaces to remove all old gasket material and debris.
- Position the new upper base gasket correctly on the engine block.
- Carefully lower the cylinder head back into place over the gasket.
- Install and tighten the cylinder head bolts in the correct sequence and to the manufacturer's recommended torque specifications.
- Reattach all components, hoses, and wiring.
- Refill the cooling system, reconnect the battery, and start the engine to check for leaks.
Troubleshooting & FAQ
How do I know if my upper base gasket is failing?
Common signs of a failed base gasket include coolant or oil leaks between the cylinder head and block, engine overheating, white smoke from the exhaust (coolant burning), or a loss of engine compression.
What engines does this gasket fit?
This gasket is designed for specific Force 75, 90, and 120 HP 3 & 4-cylinder outboard engines from 1995 to 1999. Please check the compatibility table and your OEM part number (27-826549) to confirm fitment.
Does this gasket require sealant upon installation?
Most modern composite gaskets like this one are designed to be installed dry. Applying chemical sealants can sometimes interfere with a proper seal. Always follow the guidelines in your engine's official service manual.
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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