Cylinder Head Gasket – Fits Yamaha 48-55 HP 2-Stroke (Replaces 697-11181-00, 697-11181-A1)
Cylinder Head Gasket – Fits Yamaha 48-55 HP 2-Stroke (Replaces 697-11181-00, 697-11181-A1) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Free standard shipping on all orders under 1 KG
Cylinder Head Gasket – Fits Yamaha 48-55 HP 2-Stroke (Replaces 697-...
Product Details
This aftermarket Cylinder Head Gasket – Fits Yamaha 48-55 HP 2-Stroke (Replaces 697-11181-00, 697-11181-A1) is engineered to restore a perfect seal between the cylinder head and engine block. It is designed for compatibility with Yamaha 48 HP to 55 HP 2-cylinder, 2-stroke outboard engines manufactured between 1990 and 2005, including E48CMH and E55CMH series models.
It serves as a direct replacement for Yamaha OEM part numbers 697-11181-00, 697-11181-01, 697-11181-A0, 697-11181-A1, 697-11181-A2, and Sierra 18-3848.
- Installation is a direct replacement but requires cylinder head removal.
- Ensures a reliable seal for the metal-to-metal cylinder head interface.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 697-11181-00 |
| Yamaha | 697-11181-01 |
| Yamaha | 697-11181-A0 |
| Yamaha | 697-11181-A1 |
| Yamaha | 697-11181-A2 |
| Sierra | 18-3848 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | E48CMH | 48 | 2-Stroke | 1990–2005 | 697-11181-A1 | |
| Yamaha | 48 HP 2-Cyl | 48 | 2-Stroke | 1990–2005 | 697-11181-A1 | |
| Yamaha | 50 HP 2-Cyl | 50 | 2-Stroke | 1990–2005 | 697-11181-A1 | |
| Yamaha | E55CMH | 55 | 2-Stroke | 1990–2005 | 697-11181-A1 | |
| Yamaha | 55B | 55 | 2-Stroke | 1990–2005 | 697-11181-A1 | |
| Yamaha | 55BE | 55 | 2-Stroke | 1990–2005 | 697-11181-A1 | |
| Yamaha | 55BM | 55 | 2-Stroke | 1990–2005 | 697-11181-A1 | |
| Yamaha | 55BET | 55 | 2-Stroke | 1990–2005 | 697-11181-A1 |
Technical Specs
- Product Type
- Cylinder Head Gasket
- Installation
- Direct replacement, requires cylinder head removal
- Dimensions
- 25.5 cm (L) x 14.0 cm (W) x 0.1 cm (H)
- Weight
- 1.76 ounces (50 grams)
- Sealing Surface
- Metal-to-metal cylinder head interface
What’s in the Box
- 1 x Outboard Cylinder Head Gasket (697-11181-A1)
Installation Notes
- Disconnect the battery and drain the engine coolant completely.
- Remove any components obstructing access to the cylinder head, such as the intake manifold or wiring harnesses.
- In the reverse order of the manufacturer's tightening sequence, carefully loosen and remove the cylinder head bolts.
- Gently lift the cylinder head off the engine block. Remove the old head gasket.
- Thoroughly clean both the engine block and cylinder head mating surfaces. Ensure they are free of old gasket material, oil, and debris.
- Position the new cylinder head gasket correctly on the engine block; check for proper alignment with dowel pins.
- Carefully place the cylinder head back onto the block and gasket.
- Install the head bolts and tighten them in stages, following the manufacturer-specified torque values and sequence.
- Reassemble all previously removed components and reconnect the battery.
- Refill the cooling system, start the engine, and carefully inspect for any leaks around the cylinder head.
Troubleshooting & FAQ
How do I confirm this gasket fits my exact Yamaha model?
This gasket is designed for Yamaha 48-55 HP 2-cylinder, 2-stroke outboards from 1990–2005. The best way to ensure a match is to verify your engine model and year against the compatibility table and cross-reference your existing part number with the numbers listed, such as 697-11181-A1.
What are the signs of a blown or failing head gasket?
Common indicators of a failed head gasket include engine overheating, a noticeable loss of power and compression, white smoke from the exhaust (coolant burning in the cylinder), or a milky appearance in the engine oil, which suggests coolant and oil are mixing.
When should I replace my head gasket?
The cylinder head gasket should be replaced any time the cylinder head is removed for service or repairs. It should also be replaced immediately if you diagnose a gasket failure to prevent further engine damage.
Is this aftermarket gasket as reliable as an OEM part?
This is an aftermarket part built to meet or exceed OEM specifications. It is designed to provide the same fit, seal, and performance as the original Yamaha gasket under normal operating conditions.
Is there a specific orientation for installing this gasket?
Yes, head gaskets are not symmetrical and must be installed in the correct orientation to ensure proper sealing of coolant and oil passages. Align the gasket with the dowel pins on the engine block and match its shape to the cylinder head before tightening.
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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