on my 1986 120 hp all I did was cap off where the oil went into the engine similiar to this - https://www.thehulltruth.com/boating...hnson-vro.html

Fuel pump got weak years later so my mechanic put a fuel pump where the fuel like left the fuel tank to put positive pressure on the engine fuel pump. This was on a 23 ft center console so it was a long run for the fuel line.