1990 Johnson Evinrude "ES" 60 thru 70 Service Manual, P/N 507873, Page 202Get this manual
Screw in vacuum testerPump out to 3-6 in(76-127 mm) of mercury and see if vacuum holdsThen pump out to 15 in (381 mm) of mercury and checkIf the gearcase fails to hold on either test, put lubricant around suspected sealIf leak then stops or lubricant is drawn in, that seal is defectiveWhen the gearcase checks out properly, fill the gearcase with the proper lubricant 28Fill the gearcase with 20-22 floz(600-650 ml) of lubricant as follows :
Secure the gearcase in an upright position Remove the oil level plug and the oil filldrain plugReplace the seals if damaged Install gearcase with OMC Hi-Vis gearcase lube until lubricant appears at the oil level holeInsert the oil level plug firstInstall the filldrain plugTighten the oil level and the filldrain plugs to torque of 60-84 in Ibs(79 Nm) Inspect the gearcase oil level after the engine test has been performed