2008 Evinrude E-TEC 55MFE Technical Manual, Page 176Get this manual
COOLING SYSTEM COMPONENTS
COMPONENTS
Water Pump and Intakes
External water intakes mounted in the gearcase housing collect water and must supply the inlet side of the water pump with an unrestricted and unaerated water supplyWater is drawn into the water pump through hole in the lower plate of the water pump assemblyAll cooling water to the powerhead is provided by the water pump nylon wedge (impeller key) is used to engage the impeller bushing and driveshaft The nylon impeller housing with liner must seal against separate water pump plate The bottom plate MUST seal to gearcase The pump operates as positive displacement pump at LOW speeds (below 1500 RPM) and as centrifugal pump at HIGHER speedsRefer to WATER PUMP SERVICE on p246 for servicing
IMPORTANT: The water pump housing includes
a small hole to the rear of the water outletThis hole provides cooling water for the tip of the exhaust passageBe sure to use the correct parts when replacing the water pump