1993 Johnson Evinrude "ET" 9.9 thru 30 Service Manual, P/N 508282, Page 221Get this manual
it General Safety Warnings Before working on any part of the gearcase, read the section called Safety at the end of this manualTo avoid accidental starting of engine while servicing, twist and remove all spark plug leadsWhen using shop air for cleaning or drying parts: Be sure air supply is regulated to not more than 25 PSI (172 kPa) Be sure you use appropriate eye protection to avoid personal injuryReplace 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 equivalent