2007-2009 Yamaha F15/F20 Outboard Service Manual, Page 94Get this manual

Power unit (check and adjustment) NOTE: Use 24 mm socket to loosen the flywheel magnet nut Flywheel holder: YB-06139 4Remove the flywheel magnet and Woodruff key
S6AG5090

6Align the "1mark on the driven sprocket with the" mark on the cylinder head
S6AG5055

CAUTION:

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