Thermostat with Gasket – Fits Yamaha Outboard 25-250 HP (Replaces 6E5-12411-10, 688-12411-10)
Thermostat with Gasket – Fits Yamaha Outboard 25-250 HP (Replaces 6E5-12411-10, 688-12411-10) is backordered and will ship as soon as it is back in stock.
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Thermostat with Gasket – Fits Yamaha Outboard 25-250 HP (Replaces 6...
Thermostat with Gasket – Fits Yamaha Outboard 25-250 HP (Replaces 6E5-12411-10, 688-12411-10) is backordered and will ship as soon as it is back in stock.
Product Details
This replacement Thermostat with Gasket – Fits Yamaha Outboard 25-250 HP (Replaces 6E5-12411-10, 688-12411-10) is designed for a broad range of Yamaha engines. It is compatible with most 2-stroke models from 25 HP to 250 HP manufactured between 1984 and 2008, as well as select 4-stroke F-series outboards including F25, F30, F40, F50, and F60 models.
This kit serves as a direct replacement for multiple Yamaha OEM part numbers, including the entire 6E5-12411 and 688-12411 series, ensuring a precise fit and function.
- Engineered for direct replacement installation, requiring no modifications.
- Maintains optimal engine temperature with a specified opening temperature of 50°C (122°F).
- Includes the thermostat, housing gasket, and seals for a complete service.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket parts.
| Brand | Part Number | Notes |
|---|---|---|
| Yamaha | 6E5-12411-30-00 | Current version. Supersedes 6E5-12411-10-00 and 6E5-12411-20-00. |
| Yamaha | 6E5-12411-20-00 | Superseded by 6E5-12411-30-00. |
| Yamaha | 6E5-12411-10-00 | Superseded by 6E5-12411-20-00. |
| Yamaha | 688-12411-11-00 | Interchangeable part. |
| Yamaha | 688-12411-10-00 | Interchangeable part. |
| Yamaha | 688-12411-01-00 | Interchangeable part. |
| Yamaha | 688-12411-00-00 | Interchangeable part. |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
Yamaha 2-Stroke Outboard Engines
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | 115TLR/TXR | 115 | 2-Stroke | 2003–2009 | 6E5-12411-30-00 | Supersedes -10 and -20 versions |
| Yamaha | 130TLR/TXR | 130 | 2-Stroke | 2003–2004 | 6E5-12411-30-00 | Supersedes -10 and -20 versions |
| Yamaha | 150TXR | 150 | 2-Stroke | 2003–2009 | 6E5-12411-30-00 | Supersedes -10 and -20 versions |
| Yamaha | V150TLR | 150 | 2-Stroke | 2003–2008 | 6E5-12411-30-00 | V-series models |
| Yamaha | VX150TLR | 150 | 2-Stroke | 2003–2004 | 6E5-12411-30-00 | VX-series models |
| Yamaha | DX150TLR | 150 | 2-Stroke | 2003–2005 | 6E5-12411-30-00 | DX-series models |
| Yamaha | Z150/LZ150 | 150 | 2-Stroke | 2003–2005 | 6E5-12411-30-00 | Z-series models |
| Yamaha | VZ150TLR | 150 | 2-Stroke | 2003–2014 | 6E5-12411-30-00 | VZ-series models |
| Yamaha | SX150TXR | 150 | 2-Stroke | 2003–2004 | 6E5-12411-30-00 | SX-series models |
| Yamaha | 175 (6G5/6R3) | 175 | 2-Stroke | 1985–2000 | 6E5-12411-30-00 | Supersedes -10 and -20 versions |
| Yamaha | Z175TXR/VZ175TLR | 175 | 2-Stroke | 2003–2012 | 6E5-12411-30-00 | Z and VZ series |
| Yamaha | 200 (6G6/6K1/6R4/6R1) | 200 | 2-Stroke | 1985–1991 | 6E5-12411-30-00 | Supersedes -10 and -20 versions |
| Yamaha | SX200TXR | 200 | 2-Stroke | 2003–2005 | 6E5-12411-30-00 | SX-series models |
| Yamaha | LZ200TXR/Z200TXR/Z200TLR | 200 | 2-Stroke | 2003–2012 | 6E5-12411-30-00 | Z-series models |
| Yamaha | VX200TLR | 200 | 2-Stroke | 2003–2005 | 6E5-12411-30-00 | VX-series models |
| Yamaha | VZ200TLR | 200 | 2-Stroke | 2003–2004 | 6E5-12411-30-00 | VZ-series models |
| Yamaha | 225 (6R5) | 225 | 2-Stroke | 1990–1997 | 6E5-12411-30-00 | 2.6L engine |
| Yamaha | 225/L225/S225 | 225 | 2-Stroke | 1994–1999 | 6E5-12411-30-00 | 3.1L engine |
| Yamaha | SX225/LX225/VX225 | 225 | 2-Stroke | 2003–2004 | 6E5-12411-30-00 | SX/LX/VX-series models |
| Yamaha | 250/L250 (61A/61B) | 250 | 2-Stroke | 1990–2002 | 6E5-12411-30-00 | Supersedes -10 and -20 versions |
| Yamaha | SX250/LX250/VX250 | 250 | 2-Stroke | 2003–2004 | 6E5-12411-30-00 | SX/LX/VX-series models |
| Yamaha | 40TLR/C40TLR | 40 | 2-Stroke | 2003–2005 | 6E5-12411-30-00 | Also NC version |
| Yamaha | 50TLR | 50 | 2-Stroke | 2003–2009 | 6E5-12411-30-00 | Also NC version |
| Yamaha | 25ELH/ELR/ESH/ESR/MLH/MSH | 25 | 2-Stroke | 2003–2009 | 6E5-12411-30-00 | Multiple configurations |
| Yamaha | 15MSH | 15 | 2-Stroke | 2003–2009 | 6E5-12411-30-00 | MSH configuration |
| Yamaha | 9.9MSH | 9.9 | 2-Stroke | 2003–2009 | 6E5-12411-30-00 | MSH configuration |
Yamaha 4-Stroke Outboard Engines
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Yamaha | F150/LF150 | 150 | 4-Stroke | 2004 | 6E5-12411-30-00 | |
| Yamaha | F200/LF200 | 200 | 4-Stroke | 2002–2004 | 6E5-12411-30-00 | |
| Yamaha | F225/LF225 | 225 | 4-Stroke | 2002–2004 | 6E5-12411-30-00 | |
| Yamaha | F25/T25 | 25 | 4-Stroke | 1998–2003 | 6E5-12411-30-00 | |
| Yamaha | F30 | 30 | 4-Stroke | 2001–2004 | 6E5-12411-30-00 | |
| Yamaha | F40/F50 | 40/50 | 4-Stroke | 1999–2004 | 6E5-12411-30-00 | |
| Yamaha | F60 | 60 | 4-Stroke | 2002 | 6E5-12411-30-00 |
Technical Specs
- Product Type
- Thermostat with Gasket
- Installation
- Direct Replacement
- Opening Temperature
- 50°C (122°F)
- Housing Material
- Stainless Steel/Brass
- Fitting Type
- Direct OEM Replacement
- Other Technical Attributes
- Includes matching gasket 61A-12414-A0
What’s in the Box
- 1 x Thermostat (6E5-12411-30-00)
- 1 x Thermostat Housing Gasket (61A-12414-A0-00)
- 2 x Thermostat Seals (688-12412-00)
Installation Notes
- Ensure the engine is completely cool and disconnect the battery.
- Place a drain pan under the engine and drain the cooling system.
- Locate the thermostat housing on the engine block or cylinder head.
- Remove the bolts securing the housing cover. Note their positions if they are different lengths.
- Carefully remove the old thermostat and gasket. Take note of the thermostat's orientation.
- Thoroughly clean the mating surfaces of the housing and cover, removing all old gasket material.
- Install the new thermostat in the correct orientation, followed by the new gasket and seals.
- Re-secure the housing cover, tightening bolts to the manufacturer's specified torque in a crisscross pattern.
- Refill the cooling system with the recommended coolant.
- Reconnect the battery, start the engine, and check for leaks as it warms up to operating temperature.
Troubleshooting & FAQ
How do I know if my thermostat is failing?
Common signs of a faulty thermostat include the engine overheating (stuck closed) or running too cold and not reaching operating temperature (stuck open). An inaccurate temperature gauge reading can also indicate a problem.
What is the functional difference between the various part numbers like 6E5-12411-10, -20, and -30?
These numbers represent revisions. The 6E5-12411-30-00 is the latest version from Yamaha, superseding the -10 and -20 versions. While all are functionally similar, the newest part reflects the most current design and material specifications.
Is this kit all I need for the replacement?
Yes, this kit is designed to be a complete solution. It includes the thermostat, the primary housing gasket, and the two necessary thermostat seals, which are often overlooked but critical for a leak-free seal.
Why is the operating temperature 50°C (122°F)?
This opening temperature is specified by the OEM for these engine models to ensure optimal performance, fuel efficiency, and longevity. It allows the engine to warm up quickly while preventing overheating under load.
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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