Re: location of zincs - 92 Johnson 140hp
Stern bracket 0433580 or 05007089;
Top of gearcase 0393023 or 0436745;
Bearing carrier inside of gearcase 0431708.
http://boatzincs.com/
iboats sells Sierra 18-6115 for stern bracket, 18-6095 for bearing carrier, and 18-6024 for top of gearcase.
Parts catalog for your model is located here:
http://shop.evinrude.com/
Zincs are shown on the midsection and gearcase diagrams.