1988 Johnson/Evinrude "CC" 40 thru 55 Models Service Manual, Page 53Get this manual
Warning Horn Test
INote To avoid possible powerhead damage, be sure the warning
horn is in operating conditionIt is advisable to check the horn at the start of each boating season and periodically during the season At Remote Control
r;;J check of the warning horn can be made by turning the key switch to the ON position and inserting another key or thin piece of metal into the slot in the controlThe horn should soundIf the horn does not sound, check the horn and the complete system