2001-2002 Yamaha 50HP F50Z/T50Z Ouboard 4-stroke engines service manual, Page 166Get this manual
IpOWRIIfriJ: IPower unit Do not get the lapping compound on the valve stem and valve guide10After every lapping procedure, be sure to clean off any remaining lapping compound from the cylinder head and the valve11Check the valve seat contact area of the valve again
862Y5520
Checking the rocker arms and rocker arm shaft
1Check the rocker arms, rocker arm shaft, and rocker arm contact surface for wearReplace if necessaryMeasure the rocker arms inside diameter
Cam lobe: Intake: 30.89-30.99 Exhaust: 30.82-30.92 Cam lobe (6): Intake: 25.95-26.05 Exhaust: 25.95-26.05