1996 Johnson/Evinrude Outboards 25, 35 3-Cylinder Service Manual, Page 82Get this manual
12Remove the two screws securing the fuel outlet fitting retainer to the oil mixing unit coverRemove the retainer, fitting, and O-ringDiscard the O-ring 13Pinch the piston seal and roll it off the pistonDiscard the piston seal
14Remove six screws securing the mixing unit bracket to the mixing unitNote the position of the bracket, then remove it
15Remove the remaining two screws and washers Separate the oil mixing cover from the intermediate housing Remove the piston and diaphragm assemblythe small springand the large spring CDDiscard the piston and diaphragm assembly