90-822900 Service Manual – Mariner/Mercury Seapro Marathon 3L 225HP

The Seapro Marathon Service Manual (part number 90-822900) is the official factory reference for Mariner and Mercury 3-Litre Seapro/Marathon outboards, including 225 Carburetor, 225 EFI, and 250 EFI models. Designed for U.S. engines with serial numbers 0D280813 and higher, this manual offers precise procedures direct from Brunswick Corporation’s engineers.

Inside this Seapro Marathon Service Manual, you’ll find complete coverage of every major system: hydraulic power trim, powerhead, ignition, fuel delivery, cooling systems, and mid-section. Detailed exploded diagrams guide you through component identification, while torque specs, pressure readings, and step-by-step instructions streamline each task. Troubleshooting charts help you quickly diagnose issues without unnecessary downtime.

Unlike aftermarket books, this Seapro Marathon Service Manual uses factory-approved specifications so your repairs meet original engineering standards. Technicians and hands-on boat owners benefit from its clear layout, allowing easy navigation between service sections. Whether you’re checking trim rod pressure or performing carburetor adjustments, each procedure is broken down into manageable steps so you can work with confidence.

Printed on workshop-durable paper, this manual is ready for heavy use around grease, oil, and marine environments. Arizona Outboard Dismantlers proudly supplies genuine manuals like this one to help you service your investment properly, improve performance, and extend the life of your Mariner or Mercury outboard.