Valve Seat Gasket – Fits Yamaha 6HP & 8HP Outboards (Replaces 6G1-13621-A1-00)
Valve Seat Gasket – Fits Yamaha 6HP & 8HP Outboards (Replaces 6G1-13621-A1-00) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Valve Seat Gasket – Fits Yamaha 6HP & 8HP Outboards (Replaces 6...
Product Details
This high-quality Valve Seat Gasket is designed for a precise fit on Yamaha 6 HP and 8 HP 2-stroke outboard engines manufactured from 1993 to 2003 and later. It ensures a proper seal within the reed valve intake system, restoring performance and preventing air leaks.
This part directly replaces Yamaha OEM part numbers 6G1-13621-00-00 and 6G1-13621-A1-00, offering a reliable and cost-effective alternative.
- Installs in the engine's reed valve intake system.
- Engineered for gasoline-fueled 2-stroke marine engines.
- Package includes one valve seat gasket.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number | Superseded By |
|---|---|---|
| Yamaha | 6G1-13621-00-00 | 6G1-13621-A1-00 |
| Yamaha | 6G1-13621-A1-00 |
Engine & Model Compatibility
Confirm your engine model and year in the table below to ensure correct fitment.
This gasket is compatible with a wide range of Yamaha 2-stroke outboard models from 6 HP to 8 HP.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 6MLHR | 6 | 2-Stroke | 1993 | 6G1-13621-A1-00 | |
| Yamaha | 6MSHR | 6 | 2-Stroke | 1993 | 6G1-13621-A1-00 | |
| Yamaha | 6/8MHS | 6/8 | 2-Stroke | 1994 | 6G1-13621-A1-00 | |
| Yamaha | 6/8MHT | 6/8 | 2-Stroke | 1995 | 6G1-13621-A1-00 | |
| Yamaha | 6/8MHU | 6/8 | 2-Stroke | 1996 | 6G1-13621-A1-00 | |
| Yamaha | 6MHV | 6 | 2-Stroke | 1997 | 6G1-13621-A1-00 | |
| Yamaha | 8MHV (6N0) | 8 | 2-Stroke | 1997 | 6G1-13621-A1-00 | |
| Yamaha | 8MSHZ | 8 | 2-Stroke | 2001 | 6G1-13621-A1-00 | |
| Yamaha | 8MSHA | 8 | 2-Stroke | 2002 | 6G1-13621-A1-00 | |
| Yamaha | 8MSHB | 8 | 2-Stroke | 2003 | 6G1-13621-A1-00 | |
| Yamaha | 8MHR | 8 | 2-Stroke | 1993 | 6G1-13621-A1-00 | |
| Yamaha | 8MLHP | 8 | 2-Stroke | 1991 | 6G1-13621-A1-00 | |
| Yamaha | 8MSHP | 8 | 2-Stroke | 1991 | 6G1-13621-A1-00 | |
| Yamaha | 8LN, 8SN | 8 | 2-Stroke | 1984 | 6G1-13621-A1-00 | |
| Yamaha | 8LK, 8SK | 8 | 2-Stroke | 1985 | 6G1-13621-A1-00 | |
| Yamaha | 8LJ, 8SJ | 8 | 2-Stroke | 1986 | 6G1-13621-A1-00 | |
| Yamaha | 8LH, 8SH | 8 | 2-Stroke | 1987 | 6G1-13621-A1-00 | |
| Yamaha | 8LG, 8SG | 8 | 2-Stroke | 1988 | 6G1-13621-A1-00 | |
| Yamaha | 8LF, 8SF | 8 | 2-Stroke | 1989 | 6G1-13621-A1-00 | |
| Yamaha | 8LD, 8SD | 8 | 2-Stroke | 1990 | 6G1-13621-A1-00 |
Technical Specs
- Product Type
- Valve Seat Gasket
- Installation
- Engine intake system
- Fuel Type
- Gasoline
- Dimensions
- 7.25" H x 6.0" W x 0.63" L
- OEM Part Number
- 6G1-13621-A1-00
- Supersedes
- 6G1-13621-00-00
- Other Technical Attributes
- For reed valve intake system
What’s in the Box
- 1 x Gasket, Valve Seat (6G1-13621-A1-00)
Installation Notes
- Disconnect the battery and ensure the engine is cool.
- Access the engine's intake manifold and reed valve assembly per your service manual.
- Carefully remove the old valve seat gasket, noting its orientation.
- Thoroughly clean both mating surfaces, ensuring they are free of old gasket material and debris.
- Place the new gasket into position, ensuring it aligns with all bolt holes and passages.
- Reassemble the components and torque all fasteners to the manufacturer's specifications.
Troubleshooting & FAQ
How do I confirm this gasket fits my specific Yamaha outboard?
Verify your engine's full model name and year against the "Engine & Model Compatibility" table. Matching the OEM part number (6G1-13621-A1-00 or 6G1-13621-00-00) from your service manual is the most reliable method.
What are the common signs of a failed valve seat gasket?
Symptoms of a faulty gasket include poor or rough idling, difficulty starting, reduced engine power, and backfiring. These issues are often caused by an air leak at the intake.
Should I use a sealant with this gasket?
This type of gasket is typically designed to be installed dry. Applying sealants can sometimes cause improper seating or block small passages. Always consult your engine’s official service manual for the recommended procedure.
How is an aftermarket part different from OEM?
This listing is for an aftermarket replacement, not an original equipment manufacturer (OEM) part. It is engineered to meet or exceed OEM specifications for fit, form, and function using comparable materials. Our parts are produced in an ISO 9002 certified facility and are batch-inspected for quality and consistency.
What are the shipping speed and cost?
We ship worldwide, with most orders arriving in 5–15 days via standard shipping. Standard shipping is free. Expedited shipping options, if available for your location, will be presented at checkout.
What is the warranty and return policy?
This product is covered by a 1-year warranty against manufacturing defects under normal marine use. If you encounter an issue, please contact our support team with your order number. Returns for unused items in their original condition are accepted within our standard return window. Please see our full policy page or contact us for instructions.
Safety & Important Info
- Verify images and specifications against your original part before purchasing. If anything differs—even if your model appears on a compatibility list—do not purchase.
- This is an aftermarket replacement part, not an OEM component.
- Professional installation is highly recommended for safety, performance, and to prevent engine damage.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and rigorously tested for real-world reliability.
- Fast Global Fulfillment — We offer free standard delivery to most regions, with typical transit times of 5–15 days.
- Manufacturer-Direct Value — By working directly with manufacturers, we provide fair pricing without compromising on materials or quality control.
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