Honda Outboards BF40A/BF50A Service Manual, Page 415Get this manual
BF40A-BF50A 12) Apply ATF to the sealing washer, and set it in the valve body at right anglesBe careful not to set it at an inclined angle, which can lead to the collapsed sealing washer13)Apply ATF to new D-ring and new O-ring, and install them on the manual valve14)Tighten the manual valve to the specified torque, and set the internal circlip in the groove in the valve body securelyTORQUE: 1.7 N-m (0.17 kgf-m, 1.2Ibf-ft)
[2] O-RI 1.2 5.8 mm
[3] O-RING 2.4 9.8 mm
[1] MANUAL VALVE