1992 Johnson Evinrude "EN" 40 thru 55 Service Manual, P/N 508143, Page 80Get 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
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 tank1Start engine and allow it to reach normal operating temperature