Honda BF50 (5HP), BF5A Outboard Motors Shop Manual 2014, Page 33Get this manual
BF50BF5A FUEL PUMP
DIAPHRAGM DISASSEMBl Y:
Push the diaphragm down and turn it until the foot is parallel with the groove in the push rod
REASSEMBL Y:
Check the diaphragm for holes, deterioration and tearsReplace if necessary
PUSH ROD REASSEMBl Y:
After assembly, press the push rod to make sure it moves smoothly