Carburetor Needle Valve Seat – Fits Yamaha 9.9/15HP 2-Stroke & Mercury 8/15HP (Replaces 6E8-14390-12, 14216M)
Carburetor Needle Valve Seat – Fits Yamaha 9.9/15HP 2-Stroke & Mercury 8/15HP (Replaces 6E8-14390-12, 14216M) is backordered and will ship as soon as it is back in stock.
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Carburetor Needle Valve Seat – Fits Yamaha 9.9/15HP 2-Stroke & ...
Product Details
This aftermarket Carburetor Needle Valve Seat is designed for a precise fit on select Yamaha and Mercury outboard motors. It is compatible with Yamaha 9.9–15HP 2-Stroke E-Series and C/D models from 1986–1995, as well as Mercury W8(677), W15(684), and 15C(684) models that use a 6E8-04 series carburetor.
It serves as a direct interchange for Yamaha part number 6E8-14390-12-00, Mercury 14216M, and Sierra 18-7056.
- Installs via a simple press-fit method.
- Essential component for regulating fuel flow within the carburetor.
- Constructed from durable, corrosion-resistant brass.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 6E8-14390-12-00 | Supersedes original part 6E7-14390-12-00 |
| Mercury | 14216M | |
| Sierra | 18-7056 | Aftermarket cross-reference |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Yamaha, this part fits various 9.9HP and 15HP 2-stroke models, primarily within the E-Series, C, and D model lines from 1986 to 1995.
For Mercury, this seat is compatible with W8, W15, and 15C models equipped with specific carburetor series.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 15SJ | 15 | 2-Stroke | 1986 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 15LJ | 15 | 2-Stroke | 1986 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 15SH | 15 | 2-Stroke | 1987 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 9.9SJ | 9.9 | 2-Stroke | 1986 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 9.9LH | 9.9 | 2-Stroke | 1987 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 9.9SH | 9.9 | 2-Stroke | 1987 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 9.9LJ | 9.9 | 2-Stroke | 1986 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 15ELH | 15 | 2-Stroke | 1987 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 15ESH | 15 | 2-Stroke | 1987 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 9.9ELH | 9.9 | 2-Stroke | 1987 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 9.9ESH | 9.9 | 2-Stroke | 1987 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 9.9ELJ | 9.9 | 2-Stroke | 1986 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 15ESJ | 15 | 2-Stroke | 1986 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 9.9ESJ | 9.9 | 2-Stroke | 1986 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 15LH | 15 | 2-Stroke | 1987 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 15ELJ | 15 | 2-Stroke | 1986 | 6E8-14390-12-00 | Air Cleaner Carburetor (9.9H 15H) |
| Yamaha | 15ELHS | 15 | 2-Stroke | 1994 | 6E8-14390-12-00 | INTAKE |
| Yamaha | 15ESHR | 15 | 2-Stroke | 1993 | 6E8-14390-12-00 | INTAKE |
| Yamaha | 15ELF | 15 | 2-Stroke | 1989 | 6E8-14390-12-00 | Intake - Carburetor |
| Yamaha | 15MLHP | 15 | 2-Stroke | 1991 | 6E8-14390-12-00 | Intake - Carburetor |
| Yamaha | 15MSHR | 15 | 2-Stroke | 1993 | 6E8-14390-12-00 | INTAKE |
| Yamaha | 9.9MSHS | 9.9 | 2-Stroke | 1994 | 6E8-14390-12-00 | INTAKE |
| Yamaha | E8D | 8 | 2-Stroke | 1986–1995 | 6E8-14390-12-00 | Also fits 6E8-04 series carburetors |
| Yamaha | 9.9D | 9.9 | 2-Stroke | 1986–1995 | 6E8-14390-12-00 | Also fits 6E8-04 series carburetors |
| Yamaha | 15D | 15 | 2-Stroke | 1986–1995 | 6E8-14390-12-00 | Also fits 6E8-04 series carburetors |
| Mercury | W8 | 8 | 2-Stroke | 14216M | Models with 677 designation | |
| Mercury | W15 | 15 | 2-Stroke | 14216M | Models with 684 designation | |
| Mercury | 15C | 15 | 2-Stroke | 14216M | Models with 684 designation |
Technical Specs
- Product Type
- Carburetor Needle Valve Seat
- Installation
- Press-fit
- Fuel Type
- Gasoline
- Housing Material
- Brass
- Housing Color
- Metallic
- Dimensions
- 4.5" (L) x 0.25" (W) x 3.5" (H)
- Fitting Type
- Carburetor Float Valve Seat
- Warranty
- Varies by manufacturer (typically 1 year limited)
- Other Technical Attributes
- Component of carburetor fuel flow regulation system
What’s in the Box
- 1 x Needle Valve Seat (Replaces Yamaha 6E8-14390-12-00 & Mercury 14216M)
Installation Notes
- Disconnect the fuel line and drain the carburetor.
- Remove the carburetor from the engine.
- Carefully disassemble the carburetor, removing the float bowl to access the float and needle.
- Use an appropriate tool to gently press out the old needle valve seat from the carburetor body.
- Clean the seat housing thoroughly to remove any debris or sealant residue.
- Align the new valve seat and press it firmly and evenly into place until fully seated.
- Reinstall the needle, float, and float bowl, ensuring the float height is set to the manufacturer's specification.
- Reassemble and reinstall the carburetor, reconnect the fuel line, and check for leaks before starting the engine.
Troubleshooting & FAQ
How do I know if my carburetor needle valve seat is failing?
Common signs include fuel leaking from the carburetor (overflowing), a flooded engine that is difficult to start, rough idling, or black smoke from the exhaust, indicating a rich fuel mixture.
Is this a press-fit part? Do I need special tools?
Yes, this is a press-fit component. While some mechanics use a socket or dowel of the correct size to gently tap it into place, using a dedicated press tool is recommended to ensure it seats evenly without damage.
Will this fit a Yamaha 4-stroke engine?
No, this part is specifically designed for the 2-stroke Yamaha and Mercury models listed in the compatibility table. It is not compatible with 4-stroke engines.
Does this part come with the needle?
No, this listing is for the needle valve seat only. The needle is sold separately.
What causes this part to wear out?
Wear is typically caused by corrosion from water in the fuel, deterioration from ethanol-blended fuels, or abrasive debris passing through the fuel system. A poor seal can then develop between the needle and seat.
Is sealant required during installation?
No sealant or adhesive should be used. The part is designed to create a seal via a precise interference fit with the carburetor body.
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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