Moeller Universal Marine Boat Engine Moeller offers a wide series of engine flushers that extend your engine life quickly, easily and effectively. The Universal Round Cup Engine Flusher Features: Flushes contaminates from bottom of unit Cooling Systems Removes salt and mineral buildup with a simple flush that quickly slides over side water inlets on most inboard and lower outboard units. Install in seconds using just a garden hose. No tools needed.