Exhaust Manifold Gasket – Fits Yamaha 25-30HP Outboards (Replaces 664-41134-A0-00)
Exhaust Manifold Gasket – Fits Yamaha 25-30HP Outboards (Replaces 664-41134-A0-00) is backordered and will ship as soon as it is back in stock.
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Delivery and Shipping
Free standard shipping on all orders under 1 KG
Exhaust Manifold Gasket – Fits Yamaha 25-30HP Outboards (Replaces 6...
Product Details
This aftermarket Exhaust Manifold Gasket creates a secure seal between the engine block and the exhaust manifold, preventing damaging exhaust leaks. It is designed for a direct-fit replacement on a range of Yamaha 2-stroke outboards from 25–30HP, including specific CV25, CV30, C25, and C30 models manufactured between 1984 and 1996.
It serves as a direct interchange for Yamaha part numbers 664-41134-00-00 and 664-41134-A0-00, as well as Sierra 18-99010 and GLM Marine 38042.
- Installation: Engineered for a direct-fit, OEM-equivalent installation.
- Material: Constructed from a durable, heat-resistant composite to withstand demanding marine exhaust conditions.
- Function: Provides a reliable seal between the exhaust manifold and other engine components to prevent leaks.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Yamaha | 664-41134-00-00 |
| Yamaha | 664-41134-A0-00 |
| Sierra | 18-99010 |
| GLM Marine | 38042 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
Designed for compatibility with the following Yamaha outboard models.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 25ELN, 25ESN, 25LN, 25SN | 25 | 2-Stroke | 1984 | 664-41134-A0-00 | |
| Yamaha | 25ELK, 25ESK, 25LK, 25SK | 25 | 2-Stroke | 1985 | 664-41134-A0-00 | |
| Yamaha | 25ELJ, 25ESJ, 25LJ, 25SJ | 25 | 2-Stroke | 1986 | 664-41134-A0-00 | |
| Yamaha | 25ELH, 25ESH, 25LH, 25SH | 25 | 2-Stroke | 1987 | 664-41134-A0-00 | |
| Yamaha | CV25ELD, CV25EMLD | 25 | 2-Stroke | 1990 | 664-41134-A0-00 | |
| Yamaha | C25ELHP, C25ELRP | 25 | 2-Stroke | 1991 | 664-41134-A0-00 | |
| Yamaha | 30ELN, 30ESN | 30 | 2-Stroke | 1984 | 664-41134-A0-00 | |
| Yamaha | 30ELK, 30ESK | 30 | 2-Stroke | 1985 | 664-41134-A0-00 | |
| Yamaha | 30ELJ, 30ESJ | 30 | 2-Stroke | 1986 | 664-41134-A0-00 | |
| Yamaha | CV30ELF | 30 | 2-Stroke | 1989 | 664-41134-A0-00 | |
| Yamaha | CV30ELD | 30 | 2-Stroke | 1990 | 664-41134-A0-00 | |
| Yamaha | C30ELRP | 30 | 2-Stroke | 1991 | 664-41134-A0-00 | |
| Yamaha | C30ELRR | 30 | 2-Stroke | 1993 | 664-41134-A0-00 | |
| Yamaha | 20C (6A9) | 20 | 2-Stroke | 1985–1996 | 664-41134-A0-00 | International model |
| Yamaha | 25D (695) | 25 | 2-Stroke | 1985–1993 | 664-41134-A0-00 | International model |
| Yamaha | 30A (689) | 30 | 2-Stroke | 1985–1990 | 664-41134-A0-00 | International model |
Technical Specs
- Product Type
- Exhaust Manifold Gasket
- Installation
- Direct-fit, OEM replacement
- Material
- Heat-resistant composite
- Connection
- Seals exhaust manifold to exhaust components
- Purpose
- Prevents exhaust leaks between engine components
- Dimensions
- 6.0" x 6.0" x 0.25"
- Reusability
- Single-use (replace whenever manifold is removed)
- Heat Resistance
- Designed for high-temperature exhaust applications
- Other Technical Attributes
- Factory-original exhaust manifold gasket design
What’s in the Box
- 1 x Gasket, Exhaust Manifold 2 (664-41134-A0-00)
Installation Notes
- Ensure the engine is off and cool. Disconnect the battery for safety.
- If necessary, drain the engine's cooling system to a level below the exhaust manifold.
- Carefully remove any components obstructing access to the exhaust manifold.
- Systematically loosen and remove the bolts securing the manifold to the engine block.
- Gently detach the manifold and remove the old gasket. Note its orientation before removal.
- Thoroughly clean both the manifold and engine block mating surfaces. All old gasket material and carbon buildup must be removed for a proper seal.
- Position the new gasket correctly onto the engine block.
- Re-install the manifold and finger-tighten the bolts.
- Torque the manifold bolts to the manufacturer's specified values and sequence.
- Reassemble all previously removed components and refill the cooling system if it was drained.
- Reconnect the battery. Start the engine and carefully inspect for any signs of exhaust or coolant leaks around the manifold.
Troubleshooting & FAQ
How do I know if my exhaust manifold gasket is failing?
Signs of a faulty gasket include visible black soot streaks around the manifold seal, an unusual ticking or puffing sound from the engine bay, decreased engine performance, or an exhaust smell in the engine compartment.
Will this fit my specific Yamaha 25HP model?
This gasket is designed for a broad range of Yamaha 25HP and 30HP 2-stroke outboards from 1984–1996. To guarantee fitment, please refer to the detailed Engine & Model Compatibility table and cross-reference your specific model and year.
Is this gasket reusable?
No, this is a single-use gasket designed to crush and create a seal. It must be replaced whenever the exhaust manifold is removed to ensure a leak-proof connection.
What is the difference between this and an OEM gasket?
This is an aftermarket part built to meet or exceed OEM specifications using comparable high-quality, heat-resistant materials. It offers a reliable, cost-effective alternative to the original manufacturer's part.
Is any sealant required during installation?
Generally, this gasket is designed to be installed dry without any additional sealants. Always consult your service manual, but applying sealant can sometimes interfere with a proper seal and is not typically recommended.
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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