Mercury - Quicksilver 821354A2 Water Pump Repair Kit Mercury & Mariner 25-50HP 2-Stroke & 4-Stroke Outboards 821354A2. Overview. Keeping your outboard's cooling system in top shape is one of the easiest ways to protect your engine. The Quicksilver 821354A2 Water Pump Repair Kit gives you everything you need to rebuild the pump on Mercury and Mariner 25-50HP 2-stroke and 4-stroke outboards.. This OEM kit includes all the essentials - the impeller, drive key, faceplate, gaskets, and water tube sea