Yamaha - Water Pump Impeller Cooling System Component 6L5-44352-00-00. Overview. The Yamaha Water Pump Impeller 6L5-44352-00-00 is one of those parts you stay on top of if you want your small outboard to keep running strong. On engines like the F2.5, even a slight drop in water flow shows up fast with higher temps or weak output. This impeller keeps water moving through the motor, so it's constantly working every time you run. Swapping it out regularly is an easy way to avoid overheating issues before they start.. Key Features. • Consistent Water Circulation - Keeps cooling water moving through the engine to maintain safe operating temperatures.. • OEM Fit Precision - Designed to match Yamaha water pump housing for proper fit and performance.. • Flexible Blade Design - Maintains efficient pumping action across different engine speeds.. • Durable Material Build - Built to handle heat, friction, and continuous marine use.. Engine & Boat Compatibility. • F2.5 Present. FAQs. Q1: How often