Lower unit screw missing - water!

Hi all. First time poster.

I have a '98 Merc 125. This last weekend I changed the lower unit fluid because I hadn't done it since last year (boat is stored in heated garage through winter). Well, somehow I didn't get the top fill screw tightened all the way, but I didn't realize it until I got home and noticed oil leaking out when I tilted it up.

Needless to say, when I pulled the bottom screw I got about 1/2 pure water and 1/2 LU oil, cleanly separated. If there is good news, I didn't run it very long, may 10 to 15 minutes total (a lot of sitting and helping the kids catch sunfish). I know the screw was at least finger tightened before I left, so it may have been on for a little of the ride.

I filled it back up with clean fluid and turned the prop with the plugs out to get the gears coated again, if that's necessary (I left the filling tube hooked up until I get a new screw). It certainly doesn't feel like any damage was done, certainly nothing significant. What are the chances that I've escaped a LU death sentence here? I used a synthetic LU oil, if that's of any help.

Thanks!

Re: Lower unit screw missing - water!

Sounds like you made it through o.k.
Now you have to get all of the water out. The best way I know how to do that is refill it and run it to get the oil and water mixed. Drain and replace the gear lube. Repeat this process until there is no longer any evidence of water.

There may be another way to flush the LU of water but I can't think of any.

HD

Re: Lower unit screw missing - water!

Very doubtful you've hurt anything, just fill it up, run it a while and drain it again to get all the water out, especially if it was salt water! Good Luck!