Cylinder Head Gasket – Fits Yamaha 50–90 HP Outboards (Replaces 688-11181-A1-00)
Cylinder Head Gasket – Fits Yamaha 50–90 HP Outboards (Replaces 688-11181-A1-00) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Cylinder Head Gasket – Fits Yamaha 50–90 HP Outboards (Replaces 688...
Product Details
This aftermarket Cylinder Head Gasket is designed for a precise fit on Yamaha 2-Stroke 50-90 HP outboard engines manufactured between 1984 and 2009. It directly replaces the original seal between the cylinder head and engine block, ensuring reliable performance across models including 75HP, 80HP, 85HP, and 90HP variants.
It serves as a direct interchange for Yamaha part numbers 688-11181-A0-00, 688-11181-A1-00, and 688-11181-A2-00, as well as Sierra Marine 18-3805.
- Engineered for direct OEM-replacement installation.
- Compatible with 2-stroke gasoline marine engines.
- Constructed from high-quality paper/composite material for a durable seal.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Superseded By |
|---|---|---|
| Yamaha | 688-11181-A0-00 | 688-11181-A1-00 |
| Yamaha | 688-11181-A1-00 | 688-11181-A2-00 |
| Sierra Marine | 18-3805 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This part is compatible with a wide range of Yamaha 2-stroke outboards from 50HP to 90HP.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. |
|---|---|---|---|---|---|
| Yamaha | 90ETLN, 90ETXN | 90 | 2-Stroke | 1984 | 688-11181-A1-00 |
| Yamaha | 90ETLK | 90 | 2-Stroke | 1985 | 688-11181-A1-00 |
| Yamaha | 90ETLJ, 90ETLJ-JD | 90 | 2-Stroke | 1986 | 688-11181-A1-00 |
| Yamaha | 90ETLH, 90ETLH-JD | 90 | 2-Stroke | 1987 | 688-11181-A1-00 |
| Yamaha | 90ETLG, 90ETLG-JD | 90 | 2-Stroke | 1988 | 688-11181-A1-00 |
| Yamaha | 90ETLF, 90ETLF-JD | 90 | 2-Stroke | 1989 | 688-11181-A1-00 |
| Yamaha | 90ETLD, 90ETLD-JD, 90ETLDA | 90 | 2-Stroke | 1990 | 688-11181-A1-00 |
| Yamaha | 90TJRP, 90TLRP | 90 | 2-Stroke | 1991 | 688-11181-A1-00 |
| Yamaha | 90TJRQ, 90TLRQ | 90 | 2-Stroke | 1992 | 688-11181-A1-00 |
| Yamaha | 90TJRR, 90TLRR | 90 | 2-Stroke | 1993 | 688-11181-A1-00 |
| Yamaha | 90TJRS, 90TLRS | 90 | 2-Stroke | 1994 | 688-11181-A1-00 |
| Yamaha | 90TJRT, 90TLRT | 90 | 2-Stroke | 1995 | 688-11181-A1-00 |
| Yamaha | 90TJRU, 90TLRU | 90 | 2-Stroke | 1996 | 688-11181-A1-00 |
| Yamaha | 90TJRV, 90TLRV, B90TLRV, C90TLRV | 90 | 2-Stroke | 1997 | 688-11181-A1-00 |
| Yamaha | C90TLRW | 90 | 2-Stroke | 1998 | 688-11181-A1-00 |
| Yamaha | C90TLRX | 90 | 2-Stroke | 1999 | 688-11181-A1-00 |
| Yamaha | 85A (688) [030], 85A (688) [999], CV85ED (6880) [010] | 85 | 2-Stroke | 1990 | 688-11181-A1-00 |
| Yamaha | 85AE (688) [030], 85AE (688) [999], 85AE (6880) [010] | 85 | 2-Stroke | 1991–1992 | 688-11181-A1-00 |
| Yamaha | 85A (688) [030], 85A (688) [999], 85A (6880) [020], 85AET (688) [010] | 85 | 2-Stroke | 1993 | 688-11181-A1-00 |
| Yamaha | 85A (688) [030], 85A (688) [999] | 85 | 2-Stroke | 1994 | 688-11181-A1-00 |
| Yamaha | 85A (688) [030], 85A (688) [999], 85AET (688) [010] | 85 | 2-Stroke | 1995 | 688-11181-A1-00 |
| Yamaha | 85A (688) [999], 85AET (688) [010] | 85 | 2-Stroke | 1996 | 688-11181-A1-00 |
| Yamaha | 85A (688) [010] | 85 | 2-Stroke | 1997 | 688-11181-A1-00 |
| Yamaha | CV85ELF | 85 | 2-Stroke | 1989 | 688-11181-A1-00 |
| Yamaha | CV85ELD, CV85ETLD | 85 | 2-Stroke | 1990 | 688-11181-A1-00 |
| Yamaha | C85TLRP | 85 | 2-Stroke | 1991 | 688-11181-A1-00 |
| Yamaha | C85TLRQ | 85 | 2-Stroke | 1992 | 688-11181-A1-00 |
| Yamaha | C85TLRR | 85 | 2-Stroke | 1993 | 688-11181-A1-00 |
| Yamaha | C85TLRS | 85 | 2-Stroke | 1994 | 688-11181-A1-00 |
| Yamaha | C85TLRT | 85 | 2-Stroke | 1995 | 688-11181-A1-00 |
| Yamaha | C85TLRU | 85 | 2-Stroke | 1996 | 688-11181-A1-00 |
| Yamaha | 80A (6H0) [999] | 80 | 2-Stroke | 1984–1993 | 688-11181-A1-00 |
| Yamaha | 80AE (6H0) [010] | 80 | 2-Stroke | 1993–1997 | 688-11181-A1-00 |
| Yamaha | 75A (692) [010], 75A (692) [999], E-75D (6920) [010] | 75 | 2-Stroke | 1990–1992 | 688-11181-A1-00 |
| Yamaha | 75A (692) [999] | 75 | 2-Stroke | 1993–1996 | 688-11181-A1-00 |
| Yamaha | 75AET (692) [010] | 75 | 2-Stroke | 1995–1997 | 688-11181-A1-00 |
| Yamaha | C75TLRS | 75 | 2-Stroke | 1994 | 688-11181-A1-00 |
| Yamaha | C75TLRT, E75MLHT | 75 | 2-Stroke | 1995 | 688-11181-A1-00 |
| Yamaha | C75TLRU, E75MLHU, P75TLHU | 75 | 2-Stroke | 1996 | 688-11181-A1-00 |
| Yamaha | P75TLHV | 75 | 2-Stroke | 1997 | 688-11181-A1-00 |
| Yamaha | P75TLHW | 75 | 2-Stroke | 1998 | 688-11181-A1-00 |
| Yamaha | P75TLHX | 75 | 2-Stroke | 1999 | 688-11181-A1-00 |
| Yamaha | 50JET (688) [011] | 50 | 2-Stroke | 1997 | 688-11181-A1-00 |
Technical Specs
- Product Type
- Cylinder Head Gasket
- Installation
- Direct OEM replacement
- Fuel Type
- 2-Stroke gasoline
- Housing Material
- Paper/composite material
- Function
- Seals between cylinder head and block
- Dimensions
- 17.75″ L × 6.38″ W × 0.13″ H
What’s in the Box
- 1 x Gasket, Cylinder Head 1 (Replaces 688-11181-A1-00)
Installation Notes
- Disconnect the battery and drain the engine's cooling system.
- Carefully remove interfering components to access and unbolt the cylinder head.
- Remove the old head gasket and thoroughly clean both the cylinder head and engine block surfaces. Ensure they are free of old gasket material, oil, and debris.
- Place the new gasket correctly, confirming its orientation. Do not use sealant unless specified by the engine's service manual.
- Reinstall the cylinder head, tightening bolts in the specified sequence and to the correct torque values.
- Reconnect all components, refill the cooling system, and check for leaks after starting the engine.
Troubleshooting & FAQ
How do I know if this gasket fits my Yamaha engine?
This gasket is designed for a wide range of Yamaha 50-90 HP 2-stroke outboards from 1984-2009. The best way to confirm fitment is to check your specific model and year against the compatibility table provided on this page. Also, cross-reference your current part number with the numbers in our Part Number Matrix.
What are the signs of a failing cylinder head gasket?
Common symptoms include engine overheating, loss of power, white smoke from the exhaust (coolant burning), a milky appearance in the engine oil (oil and coolant mixing), or visible external leaks from the engine head area.
Can I reuse my old cylinder head gasket?
No. Cylinder head gaskets are designed for single-use only. They crush to create a seal and will not seal properly if reused, leading to engine damage.
What is the difference between Yamaha part numbers 688-11181-A0, A1, and A2?
These numbers represent supersessions. 688-11181-A0-00 was replaced by 688-11181-A1-00, which was then superseded by the current part, 688-11181-A2-00. They are functionally identical for the listed applications, reflecting minor manufacturing updates over time. This aftermarket part is an equivalent for all three.
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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