1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 228Get this manual
Replacement of Upper Main Bearing Seal155 The presence of oil under the flywheel indicates leaking upper main bearing sealTo replace the seal, the bearing must be removed from the crankshaftFollow the portions of the powerhead removal, disassembly, reassembly and installation necessary to replace the upper main bearing seal
Removal of Powerhead155
To prevent electrical sparks, disconnect the battery cables at the batteryAvoid accidental starting of the engineDisconnect the two wire connectors between the stator and the powerpack23Remove the shift rod connector screw 1
Remove the four front to rear exhaust cover screws