Honda BF20A-BF25A, BF25D-BF30D Outboard Motors Shop Manual., Page 109Get this manual
HONDA BFSOAmS5A
4INSPECTION
VALVE SPRING FREE LENGTH
Measure the free length of the valve springsSTANDARD INEX SERVICE LIMIT
36.8 mm (1.46in)
35.3 mm (1.39in)
Replace the springs if they are shorter than the service limit
VALVE FACEISTEM O.DInspect each valve face for pitting or wear irregularitiesInspect each valve stem for bending or abnormal stem wearReplace the valve if necessaryMeasure and record each valve stem O.DSTANDARD
5.475-5.490 mm 10.2156-0.2161 inl 5.455-5.470 (0.2148-0.2154 in)
SERVICE LIMIT
5.45 (0.215in) 5.43 (0.214in1
Replace the valves if their O.Dis smaller than the service limit
VALVE GUIDE I.D[VALVE FACE
Ream the valve guides remove any carbon deposits before measuring (P1)01