1991 Johnson/Evinrude Models "EI" 40 thru 55 Service Manual, Page 80Get this manual
Testing Purpose
The following procedure is designed to help you isolate defective component in the boat or engine fuel system The problem might cause loss of engine performance or, if left unrepaired, might cause serious powerhead damage After you have isolated the componentrefer to Servicing, this Section, for specific repair procedures
Test Procedure "" To avoid accidental starting of engine while changing
i propellers, twist and remove all spark plug leads