2007-2009 Yamaha F15/F20 Outboard Service Manual, Page 122Get this manual
Timing belt and sprocket
S6AG5A80
S6AG5B40
3Install the power unit onto the special service tool 5, and then tighten the drive sprocket nut to the specified torque
5Hold the driven sprocket using the special service tool A, and then tighten the driven sprocket bolt to the specified torque0