1996 Johnson/Evinrude Outboards 25, 35 3-Cylinder Service Manual, Page 63Get this manual
Function Test Two tests must be conducted to ensure proper fuel deliveryThe first test will check the suction pumps' ability to draw fuel from the fuel tankThe second test will check the pressure pumps' ability to supply fuel to the oiling unit and the carburetorsConduct these tests with the motor in test tank or on the boatBefore testing, loosen fuel tank gas cap momentarily to release any pressure that may have built upFuel tank must not be more than 30 in(76 em) below fuel pumpSuction Pump Test 1Remove the fuel inlet fitting to suction fuel pump hoseConnect fuel vacuum gauge (obtained locally) between the fuel inlet fitting and the suction pump rn
2Start motor and run it at wide-open throttle Observe the gaugePump vacuum gauge should read no more than in(102 mm) of mercury (Hg)3If fuel pump does not meet this specificationcheck fuel delivery system for restriction If no restriction is found, repair or replace the suction fuel pumpWhen installing new fuel pump, apply OMC Nut Lock to threads of screwsInstall screws and torque to 24-36 inIbs(2,8-4,0 Nm)Pressure Pump Test [}] 1Remove pressure fuel pump to in-line fuel filter hoseConnect fuel pressure gauge (obtain locally) between the pressure fuel pump and the in-line fuel filter2Start motor and run it at wide-open throttleObserve the gaugePump pressure should read minimum of PSI (21 kPa)3If pressure fuel pump does not meet this specification, repair or replace the pressure fuel pump When installing new fuel pump, apply OMC Nut Lockto threads of screwsInstall screws and torque to 24-36 inIbs(2,8-4,0 Nm)