Mercury - Quicksilver Exhaust End Cap Riser Gasket Crusader & Mallory Replacement Marine-Grade Sealing Component 8M0162538. Overview. There's a certain peace that comes from maintaining your inboard engine with the right parts - the quiet satisfaction of tightening everything down, knowing the seals are clean, the components are sound and your boat is ready for another honest day on the water. The Mercury Marine part number 8M0162538 Exhaust End Cap Riser Gasket is one of those often-overlooked