1997 Johnson Evinrude "EU" 90 thru 115 90 CV Service Manual, P/N 507267, Page 83Get this manual
Recirculation System Servicing Function Test
m 1.fitting andaa1fa inI.D.filled with isopropyl alcohol.the recircuConnect clear vinyl hose between lation syringe The 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 hose
4Connect 18 inI.Dclear vinyl hose between the cylinder block or bypass cover hose fitting and syringe filled with isopropyl alcohol5Press lightly on the syringe