Honda Outboards BF40A/BF50A Service Manual, Page 403Get this manual
BF40A-BF50A 3) Remove the four mm socket bolts and remove the oil tank and motor cord bracket B[1]5 mm SOCKET BOLT (4)
4) Remove the O-ring from the cylinder CampDiscard the O-ringReplace it with new one during reassembly
[2] OIL TANK
[4] WIRE BAND CLIP (2)
I Do not reuse