Cylinder Head Gasket – Fits Yamaha 20-25 HP 4-Stroke Outboards (Replaces 6BL-11181-00-00)
Cylinder Head Gasket – Fits Yamaha 20-25 HP 4-Stroke Outboards (Replaces 6BL-11181-00-00) 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 20-25 HP 4-Stroke Outboards (Rep...
Product Details
This aftermarket Cylinder Head Gasket – Fits Yamaha 20-25 HP 4-Stroke Outboards (Replaces 6BL-11181-00-00) is designed for a precise fit on specific 4-cylinder outboard engines, primarily from the early 2000s model range. It ensures a reliable seal between the cylinder head and engine block.
This part directly replaces Yamaha OEM part number 6BL-11181-00-00 and is also used as a cross-reference for aftermarket parts 65W-11181-20-00 and 65W-11181-30-00.
- Engineered for direct OEM-level replacement.
- Constructed from durable materials for longevity in marine environments.
- Package includes one cylinder head gasket.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 6BL-11181-00-00 |
| OVERSEE/Generic | 65W-11181-20-00 |
| OVERSEE/Generic | 65W-11181-30-00 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
| Brand | Model | Rated HP | Stroke | OEM Part No. |
|---|---|---|---|---|
| Yamaha | Outboard | 20 HP | 4-Stroke | 6BL-11181-00-00 |
| Yamaha | Outboard | 25 HP | 4-Stroke | 6BL-11181-00-00 |
Technical Specs
- Product Type
- Cylinder Head Gasket
- Installation
- Direct OEM replacement
- Fuel Type
- Gasoline
- Engine Position
- Outboard
- Material
- Rubber/Composite
- Color
- Black
- Engine Compatibility
- 4-cylinder, 4-stroke
- Engine Capacity
- 4.1–5L
- Dimensions
- 22.0" L x 16.5" W x 0.5" H
- Manufacturer Part Number
- 6BL-11181-00-00
- OEM Compatibility
- Yamaha 20-25 HP 4-stroke outboards
- Other Technical Attributes
- Designed for marine environments
What’s in the Box
- 1 x Gasket, cylinder head 1 (6BL-11181-00-00)
Installation Notes
- Disconnect the boat's battery and completely drain the engine's cooling system.
- Remove the engine cover and any components obstructing access to the cylinder head.
- Systematically disconnect all sensors, fuel lines, hoses, and wiring attached to the head.
- Following the service manual's specified sequence, loosen and remove the cylinder head bolts.
- Carefully lift the cylinder head straight up from the engine block to avoid damaging the surfaces.
- Remove the old gasket. Thoroughly clean both the engine block and cylinder head mating surfaces, ensuring they are free of any old gasket material or debris.
- Position the new gasket correctly on the engine block; check alignment with dowel pins.
- Reinstall the cylinder head and torque the bolts to the manufacturer’s specifications, using the correct tightening pattern and torque values.
- Reconnect all sensors, hoses, wiring, and other components removed earlier.
- Refill the cooling system with the appropriate coolant.
Troubleshooting & FAQ
How do I know if this gasket fits my specific Yamaha outboard model year?
This gasket fits a range of Yamaha 20-25 HP 4-stroke outboards, primarily from the early 2000s. The most reliable method to ensure compatibility is to match your old part number to 6BL-11181-00-00 or the listed aftermarket equivalents. Always visually compare your existing gasket to our product images before ordering.
What are the signs of a failing cylinder head gasket?
Common symptoms include engine overheating, a noticeable loss of power, white smoke from the exhaust (indicating coolant is burning), milky or foamy engine oil (from oil and coolant mixing), or visible external coolant/oil leaks from the seam between the cylinder head and the engine block.
Should I use sealant when installing this gasket?
This gasket is designed to be installed dry. Unless your official service manual specifically recommends the use of a sealant for your engine model, do not apply any. Adding sealant can interfere with the gasket's ability to create a proper, lasting seal.
Is this part different from the genuine Yamaha part?
This is a high-quality aftermarket component designed as a direct replacement for the OEM part. It is manufactured to meet or exceed original equipment specifications for material, fit, and performance, providing a reliable and cost-effective alternative to the original.
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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