I just paid to have the lower unit replaced on my '99 Evinrude, 50 HP. The mechanic said BOTH drain plugs were missing. I changed the fluid last fall and put the plugs back myself, has anyone ever heard of these plugs backing out?
Probably oil plug gnomes. I catch them lurking in the bushes around my shop from time to time. Traps don't work, but you can get them to go away by offering some blueberries.
