Upper Casing Gasket – Fits Yamaha 20/25/30HP & WaveRunner 500 (Replaces 61T-45113-A0-00, 689-45113-A1-00)
Upper Casing Gasket – Fits Yamaha 20/25/30HP & WaveRunner 500 (Replaces 61T-45113-A0-00, 689-45113-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
Upper Casing Gasket – Fits Yamaha 20/25/30HP & WaveRunner 500 (...
Product Details
This high-quality Upper Casing Gasket – Fits Yamaha 20/25/30HP & WaveRunner 500 provides a precision seal between the upper casing and the crankcase. It's designed for a wide range of Yamaha 2-stroke outboard motors from 20-30 HP (1984–2017) and 500cc WaveRunner/WaveJammer models (1987–1992).
It directly replaces Yamaha OEM part numbers 61T-45113-A0-00, 689-45113-A1-00, 689-45113-01-00, and 689-45113-10-00, and interchanges with Sierra 18-0739.
- Ensures a reliable, leak-free seal for optimal engine performance.
- Installs between the upper casing and crankcase assembly.
- Engineered to meet or exceed original equipment specifications.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 61T-45113-A0-00 | Current active part number. |
| Yamaha | 689-45113-A1-00 | Superseded by 61T-45113-A0-00. |
| Yamaha | 689-45113-01-00 | Superseded by 689-45113-A1-00. |
| Yamaha | 689-45113-10-00 | Superseded by 689-45113-A1-00. |
| Sierra | 18-0739 | Aftermarket cross-reference. |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
Yamaha Outboards: Fits various 2-stroke 20, 25, and 30 horsepower models from 1984 to 2017. Please verify your specific model and year.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 20C (6A9) | 20 | 2-Stroke | 1985–2006 | 61T-45113-A0-00 | Various suffixes |
| Yamaha | 20CMHS (6A9) | 20 | 2-Stroke | 2003–2006 | 61T-45113-A0-00 | |
| Yamaha | 25ELN/25ESN/25LN/25SN | 25 | 2-Stroke | 1984 | 689-45113-A1-00 | |
| Yamaha | 25ELK/25ESK/25LK/25SK | 25 | 2-Stroke | 1985 | 689-45113-A1-00 | |
| Yamaha | 25ELJ/25ESJ/25LJ/25SJ | 25 | 2-Stroke | 1986 | 689-45113-A1-00 | |
| Yamaha | 25ELH/25ESH/25LH/25SH | 25 | 2-Stroke | 1987 | 689-45113-A1-00 | |
| Yamaha | 25D (695) | 25 | 2-Stroke | 1985–1993 | 61T-45113-A0-00 | |
| Yamaha | 25B/25BMHL/25BMHS | 25 | 2-Stroke | 2001–2017 | 61T-45113-A0-00 | Multiple model variations |
| Yamaha | E25BMH/E25BMHS/E25BMHL | 25 | 2-Stroke | 2003–2017 | 61T-45113-A0-00 | |
| Yamaha | C25ELHR/C25ELRR/C25MLHR/C25MSHR | 25 | 2-Stroke | 1993 | 689-45113-A1-00 | |
| Yamaha | C25ELHS/C25ELRS/C25MLHS/C25MSHS | 25 | 2-Stroke | 1994 | 689-45113-A1-00 | |
| Yamaha | C25ELHT/C25ELRT/C25MLHT/C25MSHT | 25 | 2-Stroke | 1995 | 689-45113-A1-00 | |
| Yamaha | 30ELN/30ESN | 30 | 2-Stroke | 1984 | 689-45113-A1-00 | |
| Yamaha | 30ELK/30ESK | 30 | 2-Stroke | 1985 | 689-45113-A1-00 | |
| Yamaha | 30ELJ/30ESJ | 30 | 2-Stroke | 1986 | 689-45113-A1-00 | |
| Yamaha | 30A (689) | 30 | 2-Stroke | 1985–1993 | 61T-45113-A0-00 | |
| Yamaha | 30G (61T) | 30 | 2-Stroke | 1990–1999 | 61T-45113-A0-00 | |
| Yamaha | 30H/30HMHL/30HMHS | 30 | 2-Stroke | 2001–2017 | 61T-45113-A0-00 | Multiple model variations |
| Yamaha | CV30ELF/CV30ELD | 30 | 2-Stroke | 1989–1990 | 689-45113-A1-00 | |
| Yamaha | C30ELRP/C30ELRQ/C30ELRR | 30 | 2-Stroke | 1991–1993 | 689-45113-A1-00 |
Yamaha Personal Watercraft (PWC): Fits select WaveJammer, WaveRunner, and SuperJet models.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | WJ500 (WaveJammer) | - | 2-Stroke | 1987–1990 | 61T-45113-A0-00 | 500cc model |
| Yamaha | WR500 (WaveRunner) | - | 2-Stroke | 1987–1992 | 61T-45113-A0-00 | 500cc model |
| Yamaha | SJ650 | - | 2-Stroke | 1997 | 61T-45113-A0-00 |
Technical Specs
- Product Type
- Upper Casing Gasket
- Installation Location
- Between upper casing and crankcase
- Dimensions
- 25.5 cm × 15.0 cm × 0.5 cm
- Warranty
- 1-Year Manufacturer Warranty
- Part Status
- Aftermarket (Meets OEM Specifications)
What’s in the Box
- 1 x Upper Casing Gasket (Replaces 61T-45113-A0-00 / 689-45113-A1-00)
Installation Notes
- Ensure the engine is off and the battery is disconnected for safety. Allow the engine to cool completely.
- Drain engine oil and coolant as required by your service manual to prevent spills.
- Carefully remove any components obstructing access to the upper casing. Keep fasteners organized.
- Unbolt and remove the upper casing assembly.
- Remove the old gasket and thoroughly clean both mating surfaces. Ensure they are free of old gasket material, oil, and debris.
- Position the new gasket correctly. Do not use sealant unless explicitly required by the manufacturer's service manual.
- Reinstall the upper casing, tightening bolts to the specified torque in the sequence recommended by the service manual.
- Reassemble all other components, refill fluids, and reconnect the battery.
- Start the engine and carefully inspect for any leaks around the newly sealed area.
Troubleshooting & FAQ
How do I confirm this gasket fits my exact engine model?
The most reliable method is to match your engine's model number and year against our compatibility tables. You can also cross-reference the OEM part number stamped on your old gasket or listed in your service manual with the numbers in our Part Number Matrix.
What are the common signs of a leaking or failed upper casing gasket?
Symptoms of a bad gasket include visible oil or water leaks around the seam between the upper casing and crankcase, engine overheating, a milky appearance in the oil (indicating water intrusion), or a noticeable loss of compression and power.
Should I use sealant or adhesive with this gasket?
This gasket is designed to create a seal on its own. In most cases, you should not use any additional sealant. Always consult your official service manual; if it specifies a sealant for your particular model, follow that recommendation.
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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