1993 Johnson Evinrude "ET" 90 degrees CV Service Manual, P/N 508285, Page 55Get this manual
Testing Purpose
The following procedure is designed to help you isolate defective component in the boat or engine fuel systemThe problem might cause loss of engine performance or, if left unrepaired, might cause serious powerhead damageAfter you have isolated the component, refer to Servicing, this section, for specific repair proceduresTesting Procedure
Avoid accidental starting of engine while changing propellers; twist and remove all spark plug leads
Some checks require that the engine be run at full throttle under loadInstall the correct test propeller and run the engine in suitable test tank
1Start engine and allow it to reach normal operating temperature
Push fuel hose off fuel fittingsdon't pullIf pushing won't separate hose and fitting, carefully cut the hose along its side and peel it back to avoid damaging the fittings
f1l2Install OMC Vacuum Gauge, PIN 390954or equivalent, and in(20,3 cm) of clear vinyl hose at the fuel inlet fitting on the lower engine coverSecure all connections with tie straps to eliminate air leakage