2001-2002 Yamaha 50HP F50Z/T50Z Ouboard 4-stroke engines service manual, Page 152Get this manual
IpOWRIIfriJ: IPower unit Removing the timing belt and sprockets
1Set the cylinder #1 piston position to TOC of the compression stroke by aligning the "1" mark on the driven sprocket with the" mark on the cylinder head3Remove the tensioner and timing belt
from the driven sprocket side
S62Y5120
Do not turn the drive sprocket counterclockwise, otherwise the valve system may be damagedS62Y5140
Remove the breather hose and loosen the drive sprocket nut CDLoosen the driven sprocket bolt remove the driven sprocket (J)