Yamaha - Water Pipe Assembly Engine Cooling System YF1-89617-28-53. Overview. When you're working on Yamaha engines, the cooling system is one place where everything has to move water exactly where it's supposed to go. The Yamaha Water Pipe Assembly YF1-89617-28-53 routes cooling water through the engine so heat stays under control during long runs. It's a simple piece of hardware, but it plays a big role in keeping the cooling system flowing properly. When water moves through the motor the way