Yamaha - Cooler Engine Cooling Component 6C5-21841-01-00. Overview. Heat is one of the biggest enemies of any outboard, especially when you're running long or pushing hard. This cooler helps manage that by keeping temperatures in check so the engine can run steady without stress. When these start to clog or lose efficiency, you'll notice performance drop or temps creeping higher than they should. Keeping a good cooler in place helps the motor stay consistent and reliable over time.. Key Features. • Temperature Control Support - Helps regulate engine heat for stable operation.. • Efficient Cooling Flow - Designed to move coolant effectively through the system.. • OEM Fit Accuracy - Matches Yamaha factory specs for proper installation and function.. • Corrosion Resistant Build - Built to handle saltwater exposure and harsh marine conditions.. Engine & Boat Compatibility. Verify compatibility with your specific Yamaha outboard model and part number before installation.. FAQs. Q1: What are