1987 Johnson/Evinrude CU Outboards 35A thru 55 Service Manual, Page 157Get this manual
it General Safety Warnings The engine cover is machinery guardUse caution when servicing running engineDo not wear jeweiry or loose clothingTo prevent possible fire or explosion under the engine cover after servicing: Check entire fuel system for leaks Make sure all electrical and ignition leads are routed and clamped in their original positions away from rotating engine parts which could cut or abrade wire insulationTo avoid accidental starting of engine while serVICing, take adequate precautions to disarm the ignition system: Connect engine wiring harness to boat wiring harness with key switch i,n OFF position Twist and remove all high tension leads from spark plugs Disconnect the battery cables at the batteryReplace any locking fastener (locknut or patch screw) if its locking feature becomes weakDefinite resistance to tightening must be felt when reusing locking fastenerIf replacement is indicated, use only authorized replacement or equivalentTo prevent sudden movement when starting engine and possible "man overboard" situations, test the "start-in-neutralonly" system before returning engine to customer