This may be a dumb question with an obvious answer - but - While flushing my 25 hp. 2000 Merc., I noticed water draining out of a 1/8 inch hole above where my upper gear lub screw is on my lower unit. Water drained from it for about a minute after turning off the water hose. Don't remember seeing that before. Is it the water drain for the lower unit?? I'm concerned because I had to run the motor through alot of mud and I was wondering if any damage was done. The hole is perfectly round and had paint in the inside so I don't think anything broke. Is there some sort of plug of something that fits into it like a freeze plug or something?? thanks 
