1976 7.5 HP Merc with hole in lower unit

[mfgurish]

I have a 1976 7.5 HP mercury. On the lower unit just to the rear of the oil fill hole is another hole. I have attached 2 pictures showing the hole and its relationship to the oil fill. Should it be there? I found the lower unit oil was contaminated with water at the end of last season and I am wondering if this is the cause or if I need to tear the lower unit apart and replace the seals. The engine still runs well so I it is worth fixing. Any help would be appreciated. TIA -Mike

 

[Laddies]

Re: 1976 7.5 HP Merc with hole in lower unit

That's a water drain down hole for the cavity in the rear of the exhaust to prevent freezing in cold weather