1981 Johnson/Evinrude 4HP Outboards Service Manual, Page 67Get this manual
INSTALLATION OF STANDARD GEARCASE aIf powerhead has not been removed, remove powerhead screws See Figure 6-29Lift powerhead from exhaust housing bInstall a-ring on top of driveshaftcApply OMC Moly Lube to driveshaft splinesDo not put grease on top of driveshaftdInstall gearcase, guiding water tube into water pump grommet, and shift rod into shift rod bushing eDip attaching screws in OMC Gasket Sealing CompoundInstall and torque to 5-7 ft-Ib (7.0-9.5 N.m) fInstall powerhead with new gasketTorque screws to 5-7 fHb (7.0-9.5 n.m)GEARCASE PRESSURE TEST To test gearcase sealing, proceed as followsaRemove drain plug and screw in pressure test gaugeSee Figure 6-30Stevens Experimental pressure test gauge illustrated bPump pressure up to 3-6 pounds (21-42 kPa) If pressure gauge indicates leakage, submerge gearcase in water to determine source of leakage as evidenced by bubblesIf gearcase pressure gauge does not indicate leakage, increase pressure to 16- 18 psi (110-124 kPa) If pressure does not hold, submerge gearcase in water and check for source of leakageMake necessary repairs and repeat test cScrew in vacuum testerPump out to 3"-5" of mercury and see if vacuum holdsThen pump out to 15" of mercury and check If gearcase fails to hold on either test, put oil around suspected sealIf leak then stops or oil is drawn in ,