1997 Johnsoon Evinrude "EU" 50 thru 70 3-Cylinder Service Manual, P/N 507266, Page 78Get this manual
Place vacuum passage O-ring into cavity
Apply OMC Triple-Guard grease to one end of the poppet spring and install greased end onto the air motor diaphragm's poppet valve(The grease will help stabilize the spring while assembling Install the air motor spring onto the air motor diaphragm