I don't know the answer to this but if you were to crack or get a hole in your lower unit on an outboard motor and get salt/brackish water in it would it run very far or basically over heat and go out immediately? Trying to figure out if it would go out immediately…. I have a crack in my lower unit but haven't seen water yet…

I'd think it would depend on how bad the hole was and the ratio of water to oil. Lots of motors running around out there with milky oil. Pure water and I'd expect it to burn up before you could get back to the launch.

Thanks for y'all's input, I have more than one engine but was trying to see if I should take it out before fixing it … may chance it and go out this weekend, was planning on running that engine. We were only going to go to a restaurant about 3-4 miles away

Fullback. Check to see if you have water in your lower unit oil first. Best way is to not run the motor for a few days so if it's quite a bit of water it will settle to the bottom.
Leave your top plug in and open the bottom.
If white foamy liquid or almost clearish water comes out first I would not run it as that indicates quite a bit of water may be in there.
As CS78 said lots of lower units may have milky oil. But it's NOT normal. Milky oil means there is water in some amount in the oil.
It will cause bearing failure eventually. But enough water to separate and come out if you open the plug means it's more than just a leaking prop shaft seal. (which 90% of the time is from fishing line wrapping around your prop shaft.)
You say your lower unit itself is cracked. I would like to see a good picture of that to determine what you have going on.
Depending on where the crack is and what has caused it is very important.
Your entire gear case could fail and that in turn can cause catastrophic engine damage.
It's one thing to have a little milky oil from a minute leak in a prop shaft seal. It's a total different animal to have water intrusion from a crack in your gear case.

ETA: I want to stress the key here is the amount of water currently in your gear case or how much can get in it relatively quickly.
If it's a lot then the crack may be letting in quite a bit of water. Too much water will cause fairly quick bearing failure as it's not being lubricated of course.
Saltwater will cause bearing failure much faster than fresh water due to the salt content and corrosive nature of course.
The other issue is where the crack is and why/how did it crack? Did you hit something to cause the crack or is it just cracking?
If the crack is toward the leading edge of the nose cone or longitudinal to the nose cone or prop shaft housing you could have something really bad going on.

Gunny, thanks for that info on what I should check. my buddy who knows more about outboards will look at it tmrw and do what your saying to do above and we will determine what I should do from there. This all helps… I'll let you know what we find.

BOAT- this one will hurt …lol

Here's the real issue. I'm honestly questioning how this happened, that boat has hit nothing and the dry stack marina is saying there is a crack / hole (more like a hole but I have not seen it) in the lower unit. I would know if we hit something, because we haven't torn up any props and we don't get in any shallow water. I guess there is a chance something happened. Gonna go look at it tmrw and follow your advice. Thinking about pulling it off and getting the serial number of the lower unit and seeing if Mercury has the original serial numbers.. that lower unit has never been changed. Not gonna point fingers rather just look into this "gently". They informed me today when I told them to pull my boat Saturday by noon.. kind of fishy to be honest

Good luck sir. Let me know if I can lend some help in anyway.

Yes I will thanks for your help

No thanks needed. But you are more than welcome.

Gunny456 said:

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No thanks needed. But you are more than welcome.

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One last question, do you think Mercury would have the serial number for that lower unit if I gave them the engine ID number? It's a 2019

There is not an actual serial number on Mercury lower units that coincide with that particular engines serial number.
However it may have a part number in the casting of the lower unit.
But if you gave them the model number and serial number on your engine they can give you the part number of your complete lower unit.
ETA… If it's a dual engine application the part numbers will denote right hand and left hand prop rotation. ( Sometimes noted as standard or counter rotating lower units)
If it's by chance a Mercruiser stern drive then the drive itself will have its own serial number.
But I think you are talking about an outboard in your case?

Ok thanks again

Made an edit for additional info that may help you.

Understand what you are saying. It does sound rather suspect.

Gunny- yes outboards

You boat guys really are amazing - y'all know a hell of a lot more than the "casual" boat owner like myself

One of my dealers in Austin kept demo boats in a dry stack facility. Similar to you he called them to get a boat ready and he found his boat with the skeg busted off.
They denied it till a witness came forward and said he had seen what happened.
They hit it with the forks.

Gunny456 said:

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One of my dealers in Austin kept demo boats in a dry stack facility. Similar to you he called them to get a boat ready and he found his boat with the skeg busted off.
They denied it till a witness came forward and said he had seen what happened.
They hit it with the forks.

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My boat in on the lower rack… I'm wondering if they hit it as well or if one of the "helpers" helped himself to a lower unit and replaced mine w someone's junk .. I'm gonna take some pics.. you would think the engines would have similar "wear" on the skeg

may not know so prob drink a few drinks tmrw night and enjoy life !

Check your lower unit bolts. See if they have had a recent wrench or socket on them……like seeing some freshly flaking paint on the shoulders of the hex head. Also look at the paint where the lower unit attaches and mates up to the upper exhaust housing ……If you never have had the lower units off the paint will not broken there.
Typically if a lower unit has been whacked by an underwater object hard enough to crack or knock a hole in the lower unit the vertical leading edge will have some divots or dents in it. If yours doesn't have that it probably didn't get damage by hitting something while under way.

Ok, We will give it a good look for broken paint or dents on the leading edge. My buddy also found recent picture (this summer) of the motor up out of the water and I have a clear picture of the right side of that specific motor skeg and its wear pattern …. If they don't match I'll PM you the pics and get your input ..

Roger that. Will help all I can.

No chance the lower froze, right? Freezing with water in the passages or a lot in the gear case could cause the crack if it froze.

Paint didn't match up to pics and looked like new nutts but hard to prove - I will run the numbers on the unit once it's replaced.. side blowout about the size of a quarter - not sure I agree because nothing happened running it but I'll wait till I replace it and I've asked for the blown unit - those units will be marked somehow going forward - kind of one of those learn a lesson the hard way I'm afraid.

I will also be adding new hatch locks with keys to any hatches well, esp those with equipment in them

So you pay out the wazoo to keep your boat in dry stack, buy their ice and fuel and pay them to wash down your boat then tip then for it... and they swap your parts with broken parts while your boat is put up!? Jeez I hope you're able to prove it and get someone fired. I would be finding a new dry stack or at the very least demand that they move you to an upper level

Believe me this isn't what I paid for but this isn't over yet- need to speak with the attorney next week, we have pics and will request the part - I'll never use these F s again
Is what it is- it's not gonna kill me or anything- one of those learning things- I'll have drilled holes and stuff to mark the lower units after this is done - I'll come up with something to identify them

Just FYI. It was fairly common for thieves to steal our racing lower units at races in hotel parking lots.
I used to remove the torque tab and engrave my engine serial numbers in the casting under it. Also would engrave it on the underside of the cavitation plate.
They might find the one under the cavitation plate but not the one under the torque tab.
You might also check out these tamper proof lower unit bolts. I believe they make them for Yamaha and Mercury as well.
https://www.cpperformance.com/p-98197-suzuki-lower-unit-lock-single.aspx

Different style specific for Mercury Verado.
https://www.google.com/search?q=tamper+proof+outboard+lower+unit+bolts&client=safari&hs=FPtU&sca_esv=3449db62a2c8c472&hl=en-us&source=univ&udm=28&ved=1t:6869&ictx=111&biw=312&bih=591&dpr=3#piu=ps:44&sv=CAMS6wIargISABosMmFoVUtFd2lGMHRyV19hLVRBeFctbkNZRkhaLW9OQ1VRZ2kxNkJBZ1dFQkUiygEKFDE0Mjc3MjMyNjA2OTgyMjQyMDA0EhM5MTUzMTQxOTM2MDM4ODAxMTYzGgAiEzY1Mjk3NDMwMTY2Mjc1ODc4NDUqADITNDA5ODg0OTM5Mjg0MjEzMTEyNDoSNTc2NDYyNzA0Mjc5MDI2NzU5SgJoZ1IyUENfNDA5ODg0OTM5Mjg0MjEzMTEyNHxQUk9EX1BDXzQwOTg4NDkzOTI4NDIxMzExMjRiAGoAigEAoAEDsAEAwgEAygEA2gEA4gEA8AEA-gEAkgIA2gIAMABCLTJhaFVLRXdpRjB0cldfYS1UQXhXLW5DWUZIWi1vTkNVUXJvZ0dlZ1FJRmhBRSAGKjIKDnB2ZS1TVFJFQU1fUElVEh5wdmVfU3dlLWFjV0FPcjY1bXRrUG45SFNxUUlfMTkYATABOAEgveHaKDABSggQAhgBIAEoAQ

This. And on the 6th day God made Anti-Seize. Anti-Seize is your friend!
Prop should be pulled at least annually to check for fishing line around the prop shaft and inspect the seal. Semi annually if fishing a lot. Anti Seize on prop shaft and splines and re torque to manufacturer specs.
Grease trim/tilt and steering pivot fittings annually as well.
Dialectric grease on battery terminals too.

Welcome to Gunny & Grems School of Boat Care!

Thanks guys for being so helpful.

ALL of the time - any time someone needs help.

fullback44 said:

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Paint didn't match up to pics and looked like new nutts but hard to prove-

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Just a few thoughts. If you've had water pumps serviced, those bolts have to be removed. New bolts or tool marks might not mean a ton. Id be looking for consistency in bolts and tool marks between motors.

I know from experience that all it takes is a single short drag across sandy bottom to drastically increase the paint wear on a skeg. If the skeg just has more wear than the pic, keep that in mind. Big heavy boat at low speed, you might not even feel it, outside of hearing the motors lug down for a few seconds. If it currently has a different wear pattern or less wear than the pic, that's different. Also, I think your boat has trips or quads? If the lower has been swapped, Id be looking to see if the paint and general look is consistent between the other motors.

You should do some searches on thehulltruth about marinas and dry stacks doing damage to peoples boats and then dodging responsibility. Not saying they did it, but not a new problem.

Definitely agree. Living in College Station and trailering multiple different boats to the salt, antiseize and maintenance are critical.

I use loktite 8023 marine grade antiseize on lugs once a year and anywhere else antiseize is needed. Its metal free so doesn't contribute to galvanic corrosion. Harder to get and more expensive than the normal stuff but been very happy with it. Also highly recommend sticking with galvanized wheels on trailers to reduce galvanic corrosion between aluminum wheel and steel hub. Then yearly coating the surface between the wheel face and hub with a heavy layer of lanolin based lanocote or fluid film. I've seen wheels so corroded on that you could drive down the road with all the lug bolts broken off and still not get the wheel off.