1994 Johnson/Evinrude "ER" 9.9 thru 30 outboards Service Manual, Page 123Get this manual
Troubleshooting Test Equipment
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
[!] Spark testers:
Stevens NoS21, S13C, or S48 Merc-O-Tronic No55-4S or 55-6S
Peak-reading voltmeters: Merc-O- Tronic No781 Stevens NoCD-77 Electro-Specialties NoPRV-1