1998 Johnson Evinrude "EC" 25, 35 HP 3-Cylinder Outboards Service Manual, Page 59Get this manual
Electric Primer System Servicing Function Test
1Start engine and allow it to reach normal operating temperatureSet engine speed at 2000 RPM
2While engine is running, push key inEngine should run richly and drop 1000 RPM
3Remove primer hose from any primer fitting that you suspect is clogged Connect Va in1.0clear vinyl hose between the fitting and syringe filled with isopropyl alcohol4Press lightly on the syringe plunger If fluid moves through the fitting, it is okay