Yamaha - Air Shroud Cylinder 1 Cooling System Component 7FK-12651-00-00. Overview. This is one of those parts that quietly does its job every time the engine's running. It directs airflow around cylinder one, helping keep temps even across the block. I've seen engines run a little rough or hotter on one side just because a shroud was cracked or missing. When everything's in place, the motor just runs cleaner and more balanced.. Key Features. • Cylinder-Specific Airflow Control - Directs cooling air around cylinder one for consistent temperature management.• OEM Fitment Design - Built to match factory shape and positioning for proper airflow routing.• Heat-Resistant Construction - Handles engine heat and vibration in demanding marine conditions.• Supports Balanced Cooling - Helps reduce uneven heating that can affect engine performance over time.. Engine & Boat Compatibility. Designed for Yamaha outboard engines that utilize cylinder-specific air shrouds as part of the cooling airflow s