1976 Evinrude 200 HP Outboards Service Manual, PN 5199, Page 131Get this manual
GEARCASE PRESSURE TEST To test gearcase sealing, proceed as follows: 1Remove drain plug and screw in pressure test gaugeSee Figure 6-105Stevens Experimental pressure test gauge illustrated2Pump pressure up to 3-6 poundsGearcase must hold 3-6 poundsIf 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 poundsPressure should also hold at 16-18 poundsIf pressure does not hold, submerge gearcase in water and check for source of leakageMake necessary repairs and repeat testGearcase must hold within the range of 3-6 pounds and 16-18 pounds pressure 1Oil level plug