2007-2009 Yamaha F15/F20 Outboard Service Manual, Page 93Get this manual
Power unit
6Loosen the rocker arm locknut 7, and then turn the adjusting screw until the specified valve clearance is obtained
Replacing the timing belt
CAUTION:
S6AG5060
Do not turn the flywheel magnet counterclockwise, otherwise the water pump impeller may be damagedNOTE: To remove and install the timing belt, drive sprocket, and driven sprocket, see "Removing the timing belt and sprocket" (5-30) and "Installing the sprocket and timing belt" (531)1Disconnect the spark plug caps and remove the spark plugs2Remove the thermoswitch and cooling water hose from the thermostat cover
NOTE: To decrease the valve clearance, turn the adjusting screw in direction To increase the valve clearance, turn the adjusting screw in direction f7Tighten the rocker arm locknut to the specified torqueRocker arm locknut 7: 14 Nm (1.4 kgfm, 10.3 ftlb)