1997 Johnson Evinrude "EU" 40 thru 55 2-Cylinder Service Manual, P/N 507265, Page 78Get this manual
Testing Fuel System 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 leadsunder loadInstall the correct test propeller and run the engine in suitable test tank
INote Some checks require that the engine be run at full throttle
1Start engine and allow it to reach n-ormal operating temperature
INote 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
[]] 2Install CIVIC Vacuum Gauge, PIN 390954or equivalent, and in(20,3 em) of clear vinyl hose at the fuel inlet fitting on the lower engine coverSecure all connections with tie straps to eliminate air leakage