Thermostat Kit 60°C 6G8-12411 66M-12411 for Yamaha Mercury Mariner Honda Outboard 140°F — Germany Local Warehouse
Thermostat Kit 60°C 6G8-12411 66M-12411 for Yamaha Mercury Mariner Honda Outboard 140°F — Germany Local Warehouse
Product Overview
Thermostat kit part opening at 60 °C / 140 °F for Yamaha, Mercury, Mariner and Honda outboards, one kit per pack at 63 g. It replaces Yamaha 6G8-12411-00-00 and 66M-12411-00-00, Mercury 855676A1, Honda 19300-881-741, and crosses to Sierra 18-3541, 18-3611 with gasket and 18-3642. Dispatched from our Germany local warehouse.
Sixty degrees is the cold rating the Japanese four stroke range and the Mercury carburettor motors were built around. It opens early and keeps the block cool, which is why an automotive thermostat rated at 82 °C is the wrong part for an outboard: on a long run the engine never sheds the heat it makes.
The same body is sold under three brand families, so check the number stamped on the old thermostat and on the housing before ordering. While the cover is off, look at the seal faces for corrosion pitting, and check the impeller at the same service, because an overheating outboard is more often the pump than the thermostat.
Specifications & Attributes
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Outboard thermostat kit |
| Opening Temperature | 60 °C / 140 °F |
| Application | Yamaha, Mercury, Mariner, Honda outboards |
| Net Weight | 63 g |
| Pack Size | 150 x 100 x 40 mm / 5.9 x 3.9 x 1.6 in |
| Country of Origin | Taiwan |
OEM Cross Reference
| Brand | OEM Part Numbers |
|---|---|
| Yamaha | 6G8-12411-00-00, 6G8-12411-01-00, 6G8-12411-02-00, 6G8-12411-03-00 |
| Yamaha | 66M-12411-00-00, 66M-12411-01-00 |
| Yamaha | 6AH-13411-00-00, 6E5-12411-00, 6E5-12411-01, 6E5-12411-02 |
| Mercury / Mariner | 825212, 824853, 855676, 855676A1, 825212A1 |
| Mercury / Mariner | 825212001, 855676003, 825212T02 |
| Honda | 19300-ZW9-003, 19300-881-741, 19300-921-003 |
| Sierra | 18-3541, 18-3611 with gasket, 18-3642, 18-3628-1, 18-3629 |
Compatible Engines
| Brand | Model | Horsepower | Years |
|---|---|---|---|
| Yamaha | F2.5 | 2.5 HP | 2022 to 2023 |
| Yamaha | F4 | 4 HP | 1999 to 2023 |
| Yamaha | F6 | 6 HP | 2001 to 2023 |
| Yamaha | F8, T8 | 8 HP | 1999 to 2023 |
| Yamaha | F9.9, T9.9 | 9.9 HP | 1985 to 2023 |
| Yamaha | F15 | 15 HP | 1998 to 2006 |
| Yamaha | F25, T25 | 25 HP | 1998 to 2023 |
| Yamaha | F30 | 30 HP | 2001 to 2021 |
| Yamaha | F40 | 40 HP | 1999 to 2023 |
| Yamaha | F50, T50 | 50 HP | 1995 to 2023 |
| Yamaha | F60, T60 | 60 HP | 2002 to 2023 |
| Yamaha | F70 | 70 HP | 2006 to 2023 |
| Yamaha | F80 | 80 HP | 1999 to 2000 |
| Yamaha | F100 | 100 HP | 1999 to 2000 |
| Yamaha | XF425 | 425 HP | 2006 to 2023 |
| Yamaha | XF450 | 450 HP | 2023 and up |
Honda and Mercury Coverage
| Brand | Horsepower | Note |
|---|---|---|
| Honda BF | 8 HP, 9.9 HP, 15 HP, 20 HP, 25 HP, 30 HP | Carburettor and EFI four stroke |
| Honda BF | 40 HP, 50 HP, 60 HP, 75 HP, 90 HP | Carburettor and EFI four stroke |
| Honda BF | 100 HP, 200 HP, 225 HP | Carburettor and EFI four stroke |
| Mercury / Mariner | 8 HP, 9.9 HP, 15 HP, 25 HP, 30 HP, 40 HP, 45 HP, 50 HP | See serial ranges below |
Mercury Serial Ranges
| Model | Serial Range |
|---|---|
| 8 HP carburettor | 0H000058 and up |
| 9.9 HP carburettor | 0H000058 to 0G760300 |
| 15 HP carburettor | 1B227000 to 0G760300 |
| 25 HP four stroke, 2002 to 2006 | 0T409000 to 1B344298 |
| 30 HP EFI, 2007 and up | 1C109093 to 0G760300 |
| 30 HP carburettor, 2007 and up | 1B226999 to 0G760300 |
| 40 HP carburettor, 2002 and up | 1C000001 and up |
| 40 HP EFI, 2002 and up | 1B226999 to 0T409000 |
| 45 HP carburettor | 0T178499 to 0G760300 |
| 50 HP carburettor | 0T178499 to 0G760300 |
What's Included
| Component | Qty |
|---|---|
| Thermostat kit as shown in the photographs | 1 |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | Standard |
| Packaging | Sealed retail packaging |
Shipping from Germany
| Destination | Warehouse | Note |
|---|---|---|
| Germany | Germany local warehouse | Domestic delivery, no import duty |
| Austria, Netherlands, Belgium | Germany local warehouse | EU intra-community delivery |
| France, Italy, Spain, Poland | Germany local warehouse | EU intra-community delivery |
Before You Buy
- Check the number on the old thermostat and on the housing, three brands are covered here
- Check the rating, this one opens at 60 °C and 140 °F, hot running motors use a different one
- Check the housing and cover for corrosion pitting on the seal faces
- Check the impeller at the same service, an overheating motor is often the pump
- Fit the thermostat the right way round, spring end toward the hot side
- Run on muffs and watch the head temperature climb and then hold steady
- 30-Day Easy Returns
- Ships from our Germany local warehouse
Couldn't load pickup availability
Out of stock
View full details
Boat Owners' Review
Before You Buy
Frequently Asked Questions
What is your refund policy?
We offer a 14-day hassle-free return on all products. Items must be unused and in original packaging. Every XRmarine part is also covered by our 1-year warranty against manufacturing defects. If something is not right, email us at info@xrmarineparts.com — replacement or full refund, your choice.
See our full Refund Policy for complete details.
How does shipping work?
Free international shipping on every order — no minimums. We operate a global warehouse network with a main distribution centre in Asia (10-20 business days). We also hold stock in regional warehouses across the United States, Germany, the United Kingdom, Australia, and Poland (opening soon) — most orders arrive in 1-3 business days within those countries and in 2-8 business days to nearby regions. Tracking included.
See our full Shipping Policy.
How do you keep prices fair?
We cut out the middlemen. XRmarine sources directly from quality manufacturers and sells at honest prices. Same OEM-quality parts, no dealership markup. Every order comes with free shipping, real expert support, and a 1-year warranty.
Learn more on our About Us page.
What payment methods do you accept?
We currently accept PayPal — a fast, secure way to pay online. Credit card payments (Visa, Mastercard, American Express) and Shopify Payments are being set up and will be available soon. We appreciate your patience.