Hole in the side of my leg

Hi there my dad's yamaha 9.9 4 stroke (92-95 model year) has a sizeable hole in the leg casing, I've attached a few photos of this hole, he cleaned it out but it seems to be caused by galvanic action of some sort, does anyone have any ideas what could be causing this? And what remedy would be recommended?

The engine has been ran in salt water but flushed every time its been out.

thanks,

[robert graham]

Have you checked your zinc sacrificial anodes. should be at least a couple, one on bottom outside of motor bracket and one is the trim tab on back of cavitation plate. Should also check several "ground wires" connecting different parts of the motor. Maybe you can fill that hole with JB Weld, file, sand and paint it, but it may return later there or another location. Saltwater is hell on equipment! Good Luck!

[robert graham]

Have you checked your zinc sacrificial anodes. should be at least a couple, one on bottom outside of motor bracket and one is the trim tab on back of cavitation plate. Should also check several "ground wires" connecting different parts of the motor. Maybe you can fill that hole with JB Weld, file, sand and paint it, but it may return later there or another location. Saltwater is hell on equipment! Good Luck!