Complete Mercury Racing factory service manual # 90-8M0146888 for 250R, 300R & 300R HD outboards.
Starting Mercury outboard engine serial number for this manual is 1E080503.
Manual Outline 1 - Important Information A - Master Specifications B - Maintenance C - General Information D - Outboard Installation 250R/300R Models E - Outboard Installation 300R HD F - Storage G - General Troubleshooting
2 - Electrical A - Ignition B - Charging and Starting System C - Accessories D - Throttle and Shift 3 - Fuel System A - Induction System B - Service Procedures C - Emissions 4 - Powerhead A - Cylinder Block/Crankcase B - Cylinder Head C - Lubrication D - Cooling 5 - Midsection A - Transom Bracket and Driveshaft Housing B - Conventional Midsection (CMS) Tri-Ram Power Trim C - Heavy Duty Midsection with Remote Trim Pump D - Upper and Lower Cowls 6 - Gear Housing A - Right-Hand and Left-Hand Rotation (5.44 in. Diameter) B - Torque Master C - Right-Hand and Left-Hand Rotation Sport Master 7 - Steering A - Power Steering B - Hydraulic Steering C - Tie Bar Kits D - 300R HD Models with Builder Supplied Steering Systems E - Power Steering Wiring Diagrams Important Information 8 - Color Diagrams A - Color Diagrams
