Cylinder Head Gasket – Fits Yamaha 40HP 2-Stroke (Replaces 6R7-11181-A0-00, 6R7-11181-A1-00)
Cylinder Head Gasket – Fits Yamaha 40HP 2-Stroke (Replaces 6R7-11181-A0-00, 6R7-11181-A1-00) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Cylinder Head Gasket – Fits Yamaha 40HP 2-Stroke (Replaces 6R7-1118...
Product Details
The Sea Sierra Cylinder Head Gasket provides a precision seal between the engine block and cylinder head, essential for maintaining compression and preventing leaks. This gasket is designed specifically for the Yamaha 40HP 2-stroke outboard (1993) and a range of Yamaha Wave Runner and SuperJet 650cc personal watercraft models from 1990–1996.
It serves as a direct cross-reference for multiple part numbers, including Yamaha 6R7-11181-A0-00, 6R7-11181-A1-00; WSM 007-403; SBT 42-401-02; and OVERSEE 6R7-11181-00-00.
- Installs between the engine block and cylinder head to seal the combustion chamber.
- Constructed from a durable metal composite to withstand high pressure and temperatures.
- Guarantees a direct fit for compatible Yamaha engine models.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 6R7-11181-A0-00, 6R7-11181-A1-00 |
| WSM | 007-403 |
| SBT | 42-401-02 |
| OVERSEE | 6R7-11181-00-00 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
Yamaha Outboard Models
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Yamaha | 40G | 40 | 2-Stroke | 1993 | 6R7-11181-A0-00, 6R7-11181-A1-00 |
Yamaha Watercraft Models
| Brand | Model | Engine | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | SuperJet SJ650D | 650cc | 2-Stroke | 1990 | 6R7-11181-00-00, 6R7-11181-A0-00 | |
| Yamaha | SuperJet SJ650P | 650cc | 2-Stroke | 1991 | 6R7-11181-00-00, 6R7-11181-A0-00 | |
| Yamaha | SuperJet SJ650Q | 650cc | 2-Stroke | 1992 | 6R7-11181-00-00, 6R7-11181-A0-00 | |
| Yamaha | SuperJet SJ650R | 650cc | 2-Stroke | 1993 | 6R7-11181-00-00, 6R7-11181-A0-00 | |
| Yamaha | Wave Runner III | 650cc | 2-Stroke | 1990–1996 | 6R7-11181-00-00, 6R7-11181-A0-00 | Non-GP models |
| Yamaha | Wave Runner VXR | 650cc | 2-Stroke | 1991–1995 | 6R7-11181-00-00, 6R7-11181-A0-00 | |
| Yamaha | Wave Runner LX | 650cc | 2-Stroke | 1990–1993 | 6R7-11181-00-00, 6R7-11181-A0-00 | |
| Yamaha | WRA650D | 650cc | 2-Stroke | 1990 | 6R7-11181-00-00, 6R7-11181-A0-00 | |
| Yamaha | WRB650R1 | 650cc | 2-Stroke | 1993 | 6R7-11181-00-00, 6R7-11181-A0-00 | |
| Yamaha | WRB650S | 650cc | 2-Stroke | 1994 | 6R7-11181-00-00, 6R7-11181-A0-00 | |
| Yamaha | Raider Deluxe | 650cc | 2-Stroke | 1995 | 6R7-11181-00-00, 6R7-11181-A0-00 |
Technical Specs
- Product Type
- Cylinder Head Gasket
- Installation
- Between engine block and cylinder head
- Material
- Metal composite
- Compatibility
- Yamaha 40HP 2-stroke; Yamaha Wave Runner/SuperJet 650cc
- Weight
- 40g (1.4 oz)
- Dimensions
- 12.52 × 8.27 × 0.12 inches (318 × 210 × 3 mm)
- OEM Reference
- 6R7-11181-A0-00, 6R7-11181-A1-00
- Warranty
- Manufacturer dependent (typically 90 days to 1 year)
What’s in the Box
- 1 x Cylinder Head Gasket (6R7-11181-A0-00/6R7-11181-A1-00)
Installation Notes
- Disconnect the battery and allow the engine to cool completely.
- Drain the engine coolant.
- Remove any components obstructing the cylinder head, such as the intake and exhaust manifolds.
- Loosen the cylinder head bolts in the reverse order of the tightening sequence specified in your service manual.
- Carefully lift the cylinder head off the engine block. Do not pry it off with a screwdriver.
- Thoroughly clean the mating surfaces of both the engine block and the cylinder head. Ensure they are free of old gasket material, oil, and debris.
- Place the new cylinder head gasket onto the engine block, ensuring correct orientation.
- Carefully place the cylinder head back onto the block.
- Install and torque the head bolts in the specific sequence and stages required by your engine's service manual.
- Reassemble all previously removed components.
- Refill the cooling system, check all fluid levels, and start the engine to check for any leaks.
Troubleshooting & FAQ
How do I know if my cylinder head gasket is failing?
Common signs of a blown head gasket include engine overheating, a significant loss of power or compression, milky or foamy engine oil (indicating coolant has mixed with it), white smoke from the exhaust, or visible coolant leaks around the cylinder head.
Can this gasket be reused?
No. Cylinder head gaskets are designed for single-use only. They create a seal by being crushed under pressure. Once compressed, they will not provide an effective seal if reinstalled.
Is a special sealant required during installation?
Most modern head gaskets, including this one, are designed to be installed dry without any additional sealants. Always refer to your official service manual for instructions specific to your engine model.
What is the correct bolt torque sequence?
The torque sequence, pattern, and specific values are critical and unique to your engine. Always consult your service manual for the correct procedure. Failure to follow the correct sequence can lead to a warped cylinder head and gasket failure.
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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