Yamaha - Air Shroud Cylinder 1 Cooling System Component 7DX-E2651-00-00. Overview. This is one of those parts you don't think about until cooling starts acting up. It helps direct airflow exactly where cylinder one needs it, especially when the engine's working hard or sitting in heat. I've seen uneven temps across cylinders just from a missing or cracked shroud. When it's right, the motor runs more balanced and holds temperature better.. Key Features. • Targeted Cylinder Cooling - Directs airflow specifically around cylinder one for consistent temperature control.• OEM Fit and Design - Matches factory shape to ensure proper airflow routing without gaps.• Heat-Resistant Material - Built to withstand engine heat and constant vibration.• Supports Even Engine Operation - Helps prevent hot spots that can affect long-term performance.. Engine & Boat Compatibility. Designed for Yamaha outboard engines that utilize cylinder-specific air shrouds within the cooling airflow system. Commonly used