Honda Outboards BF40A/BF50A Service Manual, Page 108Get this manual
HONDA BF3EiA 4EiA
VALVE SEAT WIDTH
Measure the valve seat widthSTANDARD IN EX SERVICE LIMIT
1.25-1.55 mm (0.049-0.061 in)
2.0 mm (0.08 in)
If the valve seat width is under the standard, or over the ser vice limit, recondition the valve seatSee page 915
ROCKER ARM SHAFT 0.0Measure the 0.0of the rocker arm shaftSTANDARD SERVICE LIMIT
13.976-13.994 mm (0.5502-0.5509 in)
13.95 mm (0.549 in)
Replace the rocker arm shaft if its 0.0is smaller than the ser vice limit