Heat Is the #1 Enemy of 4-Stroke Engine Performance Boyesen SuperCooler Water Pump Cover and Impeller Kits are specifically designed to enhance the performance of your engine's cooling system. These high-flow, hydrodynamic water pump kits have been tested and designed to flow more coolant. By increasing the flow, the engine will run cooler at a more constant temperature. The Boyesen Supercooler can reduce engine temperatures by as much as ten degrees, as confirmed by tests at Team Kawasaki. How does the Supercooler achieve this? Hydrodynamics. Boyesen's investment-cast aluminum water pump cover has bigger water inlets, a sculpted design, no casting seams, less restrictive corners, a more efficient impeller and less cavitation. Win the War on Heat, Bolt on a SuperCooler NOW! Two-piece cast aluminum construction. Oil filter access for hassle-free filter changes.