Water in saildrive

[scarlet]

I have yanmar SD50 saildrive and my mechanic find a lot of water in my starboard oil. I am going for a haulout next month... It's a about a 50 hour sail/motor. Can I use the saildrives for the trip? Should I only use the other engine? Should I get towed instead? What, at this point, is safe for me to do, without doing more damage?

[SailingHarmonie]

It depends on what “a lot” of water is. If there is a puddle of water in the bottom, I’d be reluctant to run it. Water would not lubricate the moving parts. If there was simply water in emulsion in the oil, you will still have lubrication and I’d not hesitate to run it.

If there is a puddle of saltwater in the bottom deep enough to reach bearings and gears it is likely to do a significant amount of corrosion damage in a month. Saildrives are fragile things.

[Sailingallday]

Or pump it out. Put new oil in now. And be prepared to do it again enroute.

[ggray]

If you need/want to run the engine before you haul, use an extraction pump like is used to pump the engine oil out thru the dipstick tube.

Pump out as much as you can...I aimed for about 1/3 capacity on a SD20...fill with new. Run lightly in gear for a couple of minutes, and repeat maybe 8 times.

Oil should look pretty good then, unless you have a really bad leak.

If that's the case...and I've never had to do this, but maybe you could modify the fill cap with a tube and provision to SLOWLY force oil into the housing by having a header tank several feet above the waterline. Once you have injected enough oil to fill the housing, lower the tank until it's maybe 6 inches to a foot above the waterline to control the oil leakage. Don't want to pollute if you can help it.

I'd get the oil as clean as I could, and use this motor only for maneuvering.

[SV Confianza]

since you don’t know what’s causing the leak, I would t risk running the saildrive for anything longer than going in and out of the dock, and then drain and replace after using.

We had water ingress in a drive once, it came in fast, and destroyed the drive by the time we got hauled out. (About a week). Lots of corrosion.

[scarlet]

Well, there was a lot of water... We pumped as much as we could out of it. But with that much water in there, there probably is a significant amount of corrosion already. Don't know how long it was leaking. Engines haven't been run in a long time.

At this point, I'm still going to do my month long trip to get to the haul out place, and only use that engine for tight maneuvering

[Captain Bill]

I once had just a bit of water in my SD40 and ran it hard for about 20 minutes to make a bridge opening. The drive got hot and the water flashed to steam and inverted every seal in the unit and blew all of the oil out. Of course it immediately filled with sea water. It was a week before we could get hauled out and the drive was pretty much ruined. It ended up being a $3500 rebuild because there was a 4 month wait for a replacement drive. I would do my best to only use the bad drive for docking. I would also fill the drive to the top with gear oil. The room in the drive above the dip stick is only to allow for expansion when the drive gets hot. If there is no space the water will have a harder time getting in. What ever you do don't let the drive get hot though. If I remember correctly the SD50 has an oil extraction port at the base of the upper gear box that is threaded. I don't remember the size but it's small, something like 1/8 bpt. You could get a hose barb fitting for that port and attach tube leading to an oil reservoir well above the water line to maintain positive oil pressure in the unit. I would think you would still want to avoid getting it hot while you have a known bad seal, but it would keep the water out better than simply filling it all the way with oil.