1993 Johnson Evinrude "ET" 90 degrees CV Service Manual, P/N 508285, Page 80Get this manual
Recirculation System Servicing Function Test
f11 1Connect la inI.Dclear vinyl hose between the recirculation fitting and syringe filled with isopropyl alcoholThe fitting does not have to be removed from the crankcase for this test2Press lightly on the syringe plunger No fluid should move through the fitting3Draw out on the syringe plunger Air should be drawn through the fitting into the clear hosef21 4Connect Va inI.Dclear vinyl hose between the cylinder block or bypass cover hose fitting and syringe filled with isopropyl alcohol5Press lightly on the syringe Fluid should move freely through the fitting If fluid does not move through the fitting, clean it with OMC Cleaning Tool, PIN 326623Installation