Mercury Manual Operations - 90-860174B83. The Mercury Manual Operations - 90-860174B83 is a genuine OEM publication designed to provide reliable and detailed instructions for operating Mercury marine engines. Tailored to specific models, this manual ensures boaters and technicians alike can confidently follow Mercury's factory-recommended procedures for safe and efficient engine use.. Key Features. Genuine Mercury Literature - Created by Mercury for accurate operational guidance. Step-by-Step In