1991 Johnson/Evinrude Models "EI" 40 thru 55 Service Manual, Page 118Get this manual
Troubleshooting Test Equipment
r::-=J The following equipment is available from various manufacturers to support your ignition and electrical system troubleshootingManufacturer ordering addresses are on the rear inside cover of this manual
f11 Spark testers:
Stevens NoS21, S13C, or S48
Merc-O- Tronic No55-4S or 55-6S