2004+ Mercury 90HP Optimax DFI Outboard OEM Service & Repair Manual

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2004+ Mercury 90HP Optimax DFI Outboard OEM Service & Repair Manual

Model covered:

  • Mercury Model 90 DFI (S/N 0T801000 & Up)

The 2004+ Mercury 90HP Optimax DFI Outboard OEM Service & Repair Manual is the go-to reference if you’re keeping this two-stroke direct-injection motor running like it should. Designed with both marine techs and DIY owners in mind, the manual delivers factory-level service procedures in a format that makes sense in the shop—or on the dock.

Inside, you'll find everything from outboard installation specs to scheduled maintenance intervals, fuel system breakdowns, and powerhead repair steps. It covers DFI-specific systems like oil injection and emission controls, plus gearcase disassembly, cooling system checks, and trim unit servicing. Even small details like clamp bracket inspection and control linkage adjustments are included.

Content overview:

  • General information including specifications, maintenance schedules, and outboard installation
  • Detailed electrical system coverage: ignition, charging, starting, timing, and wiring diagrams
  • Fuel system service procedures for fuel pump, direct fuel injection, oil injection, and emissions
  • Powerhead diagnostics and cooling system maintenance
  • Mid-section repairs including clamp brackets, drive shaft housing, and power trim functions
  • Gear housing disassembly, inspection, and reassembly steps
  • Attachments and control linkage service procedures
  • Full-color diagrams for wiring and system overviews

Whether you're chasing a hard start issue, midrange misfire, or just want to stay ahead on maintenance, this manual helps you tackle the job with confidence.

Printable: Yes
Language: English
Compatibility: Pretty much any electronic device, incl. PC & Mac computers, Android and Apple smartphones & tablet, etc.
Requirements: Adobe Reader (free)

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