Cylinder Head Gasket 6H4-11181-A2 for Yamaha 40 50 HP 3-Cyl 2-Stroke Outboard 18-3830
Cylinder Head Gasket 6H4-11181-A2 for Yamaha 40 50 HP 3-Cyl 2-Stroke Outboard 18-3830
Product Overview
Cylinder head gasket for Yamaha 40 HP and 50 HP three-cylinder two-stroke outboards, supplied as 1 x gasket. It replaces Yamaha 6H4-11181-A2, 6H4-11181-A1 and 6H4-11181-A0, and cross-references Sierra 18-3830. The gasket fits the 40 HP models and the 50 HP, P50 and PRO50 models listed below. This is the multi-layer steel gasket that seals the head to the block, and it is the one joint on a two-stroke that sees both compression and cooling water. Once it fails, water reaches the cylinder and the engine runs rough, loses power and can hydraulic-lock.
Specifications & Attributes
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Cylinder Head Gasket |
| Engine Type | Yamaha outboard, 3-cylinder 2-stroke |
| Horsepower | 40 HP, 50 HP |
| Cylinders | 3 |
| Yamaha OEM Part Numbers | 6H4-11181-A2-00, 6H4-11181-A1-00, 6H4-11181-A0-00, 6H4-11181-01-00, 6H4-11181-00-00 |
| Quantity | 1 piece |
| Country of Origin | Taiwan |
OEM Cross Reference
| Brand | OEM Part Numbers |
|---|---|
| Yamaha Cylinder Head Gasket | 6H4-11181-A2, 6H4-11181-A1, 6H4-11181-A0, 6H4-11181-01, 6H4-11181-00 |
| Sierra | 18-3830 |
Compatible Engines
| Brand | HP | Models |
|---|---|---|
| Yamaha | 40 HP | 40 |
| Yamaha | 50 HP | 50 |
| Yamaha | 50 HP | P50 |
| Yamaha | 50 HP | PRO50 |
Verify your outboard model or serial number before ordering — send us the model, serial number, horsepower or year and we will confirm fitment.
What's Included
| Component | Qty |
|---|---|
| Cylinder Head Gasket | 1 |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | Standard |
| Packaging | Sealed retail packaging |
Before You Buy
- Verify your outboard model or serial number before ordering — the 40 HP and 50 HP three-cylinder blocks take different head gaskets by prefix
- Fit the gasket dry and clean — no sealant on a steel head gasket unless the service manual calls for it
- Have the head checked for flatness and pressure-tested while it is off; a warped head will blow the new gasket
- Renew the head bolts if the manual specifies torque-to-yield, and torque in the sequence given
- Find the cause of the original failure — an overheat or a lean carburettor will take the new gasket out the same way
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Before You Buy
Frequently Asked Questions
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We offer a 14-day hassle-free return on all products. Items must be unused and in original packaging. Every XRmarine part is also covered by our 1-year warranty against manufacturing defects. If something is not right, email us at info@xrmarineparts.com — replacement or full refund, your choice.
See our full Refund Policy for complete details.
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