Just for grins and giggles I just looked up the Owner's Manuals for a few engines from the 1960's thru 2018. Not a single one says replacing the washer annually is a requirement. Maybe a good idea, but not a specification.You are supposed to replace them every time you change lower unit oil
You can buy packs of 50 on marineengine.com i believe its 70 bucks.Anyone know where to get bottom end drain plug washers for older johnson evinrude in bulk ? Are they nylon or teflon ?