Mercury - Oil Drain Plug Seal / Washer Engine Oil Service 8M0007119. Overview. Changing your oil on a calm morning before heading out is one of those small rituals that keeps an engine healthy and a boater confident. You wipe down the drain plug, feel that familiar resistance as you tighten it, and you want to know-without a doubt-that the seal is doing its job. Mercury Marine part 8M0007119 brings that peace of mind. It is a simple yellow washer, but it carries a big responsibility: keeping you