2001-2002 Yamaha 50HP F50Z/T50Z Ouboard 4-stroke engines service manual, Page 83Get this manual
CHK ADJPeriodic checks and adjustments NOTE:
Adjust the valve clearance when the engine is coldValve clearance: Intake: 0.20 0.05 mm (0.008 0.002 in) Exhaust0.30 0.05 mm (0.012 0.002 in)
S62Y3230
Turn the flywheel clockwise and align the "4" mark on the driven sprocket with the ",A" markon the cylinder headLoosen the locknutand then turn the adjusting screw until the specified valve clearance is obtained
Do not turn the flywheel counterclockwise, otherwise the valve system may be damaged6Check the intake valve clearance for cylinders #3 and #4, and the exhaust valve clearance for cylinders #2 and #4Adjust if out of specification