2001-2014 Honda BF/BFP8D, BF/BFP9.9D Outboards Shop Manual, Page 167Get this manual
BFBC-BFS.SC 4) Remove and inspect the valve seat face The valve seat contact should be within the specified width and even all around the circumferenceStandard 0.9-1 .1 mm (0.035-0.043 in) Service limit 2.0 mm (0 .08 in)
Inspect the valve seat face for: Uneven seat widthreplace the valve and reface the valve seat Damaged face: replace the valve and reface the valve seat Contact area too high or too low: reface the valve seat The valve cannot be ground If the valve face is burned or badly worn or if it contacts the seat unevenly, replace the valve
SEAT WIDTH