1994 Johnson/Evinrude Outboards 40 thru 55 Service Manual, Page 84Get this manual
Testing Purpose
The following procedure is designed to help you isolate defecsystemtive component in the boat or engine The 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
i lers; twist and remove all spark plug leads
'" Avoid accidental starting of engine while changing propel-
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 temperaturePush 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
r:;-] 2Install OMC Vacuum Gauge, PIN 390954or equivalent, in(20,3 cm) of clear vinyl hose atthe fuel inlet fitting on the lower engine coverSecure all connections with tie straps to eliminate air leakage