2001-2002 Yamaha 50HP F50Z/T50Z Ouboard 4-stroke engines service manual, Page 154Get this manual
IpOWRIIfriJ: IPower unit 3Check that the mark on the retaining plate is aligned with the "" mark on the cylinder body
Install the tensioner and bolts, and then tighten the bolts finger tightInstall the new timing belt (J) from the drive sprocket side with its part number in the upright position6Take up the timing belt slack by turning the drive sprocket clockwise at least two full turns
Do not turn the sprockets counterclockwise, otherwise the valve system may be damaged7Tighten the tensioner bolts to the specified torque