Yamaha Outboard Thermostat 115-250hp 2-Stroke 6E5-12411-30 6E5-12411-20 Sierra
6E5-1411-30
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Yamaha Thermostat 6E5-12411-30
Precision Cooling Regulation for Yamaha Outboards
Maintaining your outboard's cooling system is vital for engine longevity. This thermostat is a critical component that ensures your Yamaha engine operates within the ideal thermal range. By opening at exactly 50°C (122°F), it allows for rapid warm-up while preventing the engine from reaching temperatures where salt minerals can solidify and clog cooling passages.
Key Features
- ✔ Direct fit OEM replacement
- ✔ Corrosion-resistant brass housing
- ✔ Consistent 50°C (122°F) opening
- ✔ Prevents salt crystal buildup
Technical Specs
| Opening Temp: | 50°C (122°F) |
| Outer Diameter: | 34mm |
| Inner Diameter: | 27mm |
| Height: | 17mm |
| Material: | Marine Brass / SS |
Compatibility / Fitment Guide
| Engine Type | HP Range | Notes |
|---|---|---|
| Yamaha 2-Stroke | 115hp to 250hp | V4 & V6 Models (6E5 Series) |
| Yamaha 2-Stroke | 9.9hp to 90hp | Broad application (96~ Newer) |
| Yamaha HPDI | 150hp / 175hp / 200hp | Z & VZ Series (2.6L) |
| Yamaha 4-Stroke | F115 | Early production models (1998-2006) |
OEM Cross Reference
| Yamaha OEM: | 6E5-12411-30, 6E5-12411-20, 6E5-12411-10, 6E5-12411-00, 688-12411-10 |
| Sierra Marine: | 18-3540, 18-3622 |
| Mallory Marine: | 9-43501, 9-43035 |
Questions & Answers
Is this a genuine original part?
This is a premium quality aftermarket replacement part, manufactured to meet or exceed original equipment (OE) standards for fitment and performance.
How do I know if it is compatible?
We recommend checking your part number. If your current thermostat is stamped with "6E5" or "688", this 50°C unit is the standard replacement. Visit 4boats.co.uk for more fitment details.
What happens if I don't replace a sticking thermostat?
If it sticks closed, the engine will overheat rapidly. If it sticks open, the engine will run too cold, causing "making oil" (fuel dilution in oil) and excessive carbon buildup.
Note: Please verify your original part number against the references above before purchasing. All technical data is based on Yamaha service standards for part 6E5-12411-30.
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