1985 OMC 65, 100 and 155 HP Models Commercial Service Manual, PN 507450-D, Page 197Get this manual
8Remove the nineteen exhaust manifold screwsUsing two screwdrivers, apply constant pressure thru to tabs of the exhaust manifold cover, exhaust manifold and exhaust manifold plateWhen separated, remove the coverthe manifold and the plate 9Remove the two smaller screws retaining the port and the starboard engine brackets10To service the shift lever bushings, remove the shift rod lever screwPull the shift rod lever off the shift leverRemove the shift lever from the crankcase11Remove the fou crankcase head screwsPu II the crankcase head free away from the powerhead 12Discard the crankcase head O-ring and its seal