Is your Yamaha 2-stroke outboard running too hot or not reaching proper operating temperature? A faulty thermostat is a common culprit. This is a direct replacement thermostat designed for a wide range of Yamaha 2-stroke V6 outboard motors from 115HP up to 250HP. The key part number is 6E5-12411-30-00, and it also replaces numbers like 6E5-12411-20-00 and 688-12411-11-00. Important Note: This is for 2-STROKE MODELS ONLY and does NOT fit the 4-stroke F-Series engines. A proper thermostat is crucial for engine health – it regulates coolant flow to keep the engine at its optimal temperature for performance and efficiency. This aftermarket part comes with a 1-year warranty and is designed to match OEM specs. Replacing it is a relatively straightforward job that can prevent costly overheating damage. If your temperature gauge is acting up, start with this affordable and critical component. Keep your Yamaha running cool and reliable all season long!