• Free shipping

  • Free help & advice

  • Hassle-free returns

  • Factory direct prices

Flash Sale now on!

FLASHSALE25

Thermostat – Fits Yamaha F225/F250/F300 4.2L V6 Outboards (Replaces 6CE-12411-00-00)

Sale price $27.49 Regular price $74.00
Shipping calculated at checkout.

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

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This OEM-quality Thermostat – Fits Yamaha F225/F250/F300 4.2L V6 Outboards is a crucial component for Yamaha 4.2L V6 four-stroke outboards, covering F225, F250, and F300 models from 2010 to 2022. It ensures proper engine temperature regulation, maintaining optimal performance and preventing overheating.

This part serves as a direct interchange for Yamaha part number 6CE-12411-00-00.

  • Regulates engine temperature at a consistent 52°C (125°F).
  • Installs directly into the engine block's thermostat housing.
  • Constructed from durable copper and brass for superior corrosion resistance in marine environments.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket.

Brand Part Number
Yamaha 6CE-12411-00-00

Engine & Model Compatibility

Confirm your engine model/year in the table below.

For Yamaha owners, this thermostat fits a wide range of 4.2L V6 offshore and VMAX SHO models. Verifying your specific model code and year is critical for ensuring a perfect match.

Brand Model Rated HP Stroke Years OEM Part No. Notes
Yamaha F225NCA 225 4-Stroke 2011–2018 6CE-12411-00-00
Yamaha F225XB 225 4-Stroke 2016–2020 6CE-12411-00-00
Yamaha F225XCA 225 4-Stroke 2010–2021 6CE-12411-00-00
Yamaha F250DET1X 250 4-Stroke 2010 6CE-12411-00-00
Yamaha F250NCA/NCB/NCB2 250 4-Stroke 2014–2022 6CE-12411-00-00
Yamaha F250NSB/NSB2 250 4-Stroke 2020–2022 6CE-12411-00-00
Yamaha F250UCA 250 4-Stroke 2010–2021 6CE-12411-00-00
Yamaha F250XB/XB2 250 4-Stroke 2016–2021 6CE-12411-00-00
Yamaha F250XCA 250 4-Stroke 2010–2019 6CE-12411-00-00
Yamaha F250XCB/XCB2 250 4-Stroke 2021–2022 6CE-12411-00-00
Yamaha F250XSB/XSB2 250 4-Stroke 2020–2022 6CE-12411-00-00
Yamaha F300BETX 300 4-Stroke 2016 6CE-12411-00-00
Yamaha F300NCA/NCB/NCB2 300 4-Stroke 2014–2021 6CE-12411-00-00
Yamaha F300NSB/NSB2/NSB7 300 4-Stroke 2020 6CE-12411-00-00
Yamaha F300UCA/UCB2 300 4-Stroke 2010–2022 6CE-12411-00-00
Yamaha F300XA 300 4-Stroke 2019–2021 6CE-12411-00-00
Yamaha F300XCA 300 4-Stroke 2010–2018 6CE-12411-00-00
Yamaha F300XCB/XCB2 300 4-Stroke 2021–2022 6CE-12411-00-00
Yamaha F300XSB 300 4-Stroke 2020 6CE-12411-00-00
Yamaha LF225XB 225 4-Stroke 2016 6CE-12411-00-00
Yamaha LF225XCA 225 4-Stroke 2011–2018 6CE-12411-00-00
Yamaha LF250UCA 250 4-Stroke 2010–2018 6CE-12411-00-00
Yamaha LF250XB/XB2 250 4-Stroke 2018–2022 6CE-12411-00-00
Yamaha LF250XCA 250 4-Stroke 2010–2020 6CE-12411-00-00
Yamaha LF250XCB/XCB2 250 4-Stroke 2021 6CE-12411-00-00
Yamaha LF250XSB/XSB2 250 4-Stroke 2020 6CE-12411-00-00
Yamaha LF300UCA/USB/USB2 300 4-Stroke 2010–2022 6CE-12411-00-00
Yamaha LF300XA 300 4-Stroke 2017–2022 6CE-12411-00-00
Yamaha LF300XCA 300 4-Stroke 2010–2019 6CE-12411-00-00
Yamaha LF300XCB/XCB2 300 4-Stroke 2021 6CE-12411-00-00
Yamaha LF300XSB/XSB2 300 4-Stroke 2020–2022 6CE-12411-00-00
Yamaha VF200XB 200 4-Stroke 2022 6CE-12411-00-00 VMAX SHO
Yamaha VF250XA 250 4-Stroke 2019–2020 6CE-12411-00-00 VMAX SHO
Yamaha VF250XB 250 4-Stroke 2022 6CE-12411-00-00 VMAX SHO

Technical Specs

Product Type
Thermostat
Installation Location
Engine Block/Thermostat Housing
Operating Temperature
52°C (125°F)
Housing Material
Copper/Brass
Product Dimensions
6.0" x 6.0" x 6.0"
Application
Used in Yamaha 4.2L V6 cooling system
Warranty
1-Year Manufacturer Warranty

What’s in the Box

  • 1 x Thermostat (6CE-12411-00-00)

Installation Notes

  1. Disconnect the vessel's battery before starting work.
  2. Ensure the engine is cool, then drain the coolant to a level below the thermostat housing.
  3. Locate and carefully remove the bolts securing the thermostat housing cover.
  4. Note the orientation of the old thermostat before removing it from the housing.
  5. Thoroughly clean the mating surfaces of the housing and its cover, removing all old gasket material.
  6. Install the new thermostat, ensuring it is seated in the correct orientation.
  7. Place a new gasket (sold separately) on the housing and reinstall the cover, tightening bolts to manufacturer torque specs.
  8. Refill the cooling system with the correct type and amount of coolant.
  9. Reconnect the battery, start the engine, and check for leaks as it warms to operating temperature.

Troubleshooting & FAQ

How do I know if my thermostat is failing?

Common signs include the engine overheating, the temperature gauge reading unusually high or low, erratic temperature fluctuations, poor engine performance, increased fuel consumption, and coolant leaks around the thermostat housing.

What is the operating temperature of this thermostat?

This thermostat is designed to begin opening at 52°C (125°F) to ensure your engine reaches and maintains its optimal operating temperature for efficiency and longevity.

Will this fit all Yamaha 4.2L V6 engines?

It fits a majority of F225, F250, and F300 4.2L V6 models from 2010 to recent years. However, you must verify your exact engine model and year against our compatibility chart to guarantee a correct fit.

Is a new gasket required for installation?

Yes, it is highly recommended to use a new thermostat housing gasket during installation to ensure a proper seal and prevent coolant leaks. This listing is for the thermostat only; gaskets are sold separately.

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

Payment methods

  • American Express
  • Apple Pay
  • Diners Club
  • Discover
  • Google Pay
  • JCB
  • Maestro
  • Mastercard
  • PayPal
  • Union Pay
  • Visa

Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.

Customer Reviews

Be the first to write a review
0%
(0)
0%
(0)
0%
(0)
0%
(0)
0%
(0)