Mercury - Quicksilver Drain Screw Gasket Kit Yamaha Replacement Sealing Washers Marine-Grade Fitment 8M0162525. Overview. Every boater knows the value of the small parts - the ones most people never think about until they fail at the worst possible moment. A simple drain screw gasket may not seem like a big deal, but anyone who maintains their own engine knows that these tiny seals hold back a lot more than oil. When they're fresh, you feel confident tightening the screw down after a gear lube c