Mercury - Quicksilver Engine Mount Support & Vibration Dampener MerCruiser Sterndrive & Inboard 66284A2. Overview. A secure engine mount makes all the difference in how your boat feels on the water. The Mercury Marine 66284A2 Quicksilver Engine Mount is designed for MerCruiser sterndrive and inboard engines, providing solid support while absorbing vibration and engine movement. Over time, mounts wear out and can cause rattling, misalignment, or harsh vibration through the hull. Swapping in this