Johnson Evinrude Outboard Motors 1956-1970 1.5-40hp repair manual., Page 142Get this manual
from the engine, operate the squeeze bulb in the fuel line until it is firm, and then to carefully observe the end of the vacuum hose to detect any fuel leakageThe smallest amount of fuel from the hose indicates damaged diaphragmThe pump must be rebuilt to restore satisfactory service of the pumpTo test the non-serviceable pump, remove the pump from the engine, operate the squeeze bulb until it is firm, and then carefully observe the vacuum hole in the back side of the pump for any indication of fuelThe SOl allest amount of fuel indicates damaged diaphragmIn this case, the pump MUST be replacedPUMP REMOVAL AND REPAIR