Mercury - Quicksilver Water Pump Impeller Repair Kit For 9.9HP 4-Stroke BigFoot Outboards 803748Q02. Overview. A reliable cooling system is key to keeping your outboard performing its best, and the Mercury Marine 803748Q02 Quicksilver Water Pump Impeller Repair Kit gives you everything you need to maintain it. Built for 2005 and newer Mercury 9.9HP 4-Stroke BigFoot outboards, this 3-piece OEM kit replaces worn water pump parts to restore proper water flow and cooling efficiency. It's made from d