2005 Yamaha F90TR 90HP Outboards Factory Service Manual, Page 85Get this manual

Power unit 6Tighten the drive sprocket nut to the specified torque
3Install the retaining plate 3, Woodruff key 4, drive sprocket 5, and nut 6, and then tighten the nutE

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NOTE: Use deep socket for this procedure
Crankshaft holder 8: YB-06552

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• ATV
• Jet Ski
• Outboard Motors
• Personal Watercraft
• Snowmobiles
• Stern Drives