5 Litre OMC 230 engine seized. Any suggestions would be helpful

Joined
Mar 30, 2010
Messages
11
To all of the experienced boaters that helped me a few years back.... Thanks a ton, I couldn't have done it without you.
Now I have different issues with a different boat.
I was given a boat from my stepfather's Aunt because she's not a boater and her husband passed away. He WAS an avid boater. He passed away in late 2012. It is a 1986 Mark Twain walk around with a cuddy. 25' with 8' beam. OMC 5.0 litre 4v. It is pretty clean and solid. There are no obvious signs of rot. The boat has not been used since Oct/Nov 2011. It was winterized and shrink wrapped until a few weeks ago when I unwrapped it. I finally got around to trying to start it and I was hoping to take it out a few times before winterizing. I shined up the terminals on every ground and hot wire I could find, drained and replaced the fuel, changed the oil and filter, and I replaced the starter because the drain hole got cloggled sometime in the last few years and water was sitting a few inched below the starter. There was a 10-12 inch rip in the shrink wrap that allowed rain water to enter. The starter appeared good, but I decided to change anyways. So, with all of that said......
I hooked up the ears and new battery and turned the key. The starter was trying to work like it should, but the flywheel would not budge. (I forgot to mention.... when I changed the starter I noticed the flywheel had plenty of rust on it. It was deep orange and covering all the surface area and in between the teeth) it concerned me enough that I used a whole can of PB blaster and let it soak for 24 hours.
Back to trying to start it up..... I tried 5 or 6 times with no luck. I then removed the spark plugs in case it was hydrolocked and I found all 8 spark plug ends to be somewhat rusted...... ok o boy!!!! Hoping for the best but knowing the potential harm, I sprayed blaster and wd40 in all cylinders and let sit over night. Tried to turn over by hand the next day with no luck (With the plugs still removed. I used a socket and breaker bar on the crank nut) I pulled pretty hard to the point of fear of breaking the bolt. The motor didn't budge.

OK, so my questions are....
* I'm going to let the cylinders and piston rings pickle a little longer, but how long should I wait?
* What would be the most likely cause of the motor seizing? Rusted flywheel or rusted pistons, rings, cylinder walls, or anything else I may not know.
* I forgot to check the gear lube in the drive unit, is it possible the drive unit is preventing the motor from turning?
* My biggest concern is how did the water get in the combustion chamber in the first place?

I do want to point out, this boat was well taken care of until the owner died, but even then it was wrapped and winterized before he died. I have every receipt and maintenance record for every season in the last 12 years with the exception of it being winterized and then not touched since 2012.
I guess I'm rambling a little much. Sorry, I'm just baffled.
Any input would mean a lot to me.

If nothing else, does anyone know of a good company I can send the engine and drive to for rebuild, while not totally bankrupting me?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
It is possible the drive is locked.
Remove it and try again.
Rust on all 8 is a bad sign.
I use Marvel Mystery Oil.
Some like it others hate it??
Or diesel fuel or diesel fuel with trans fluid.
Anything even PB Blaster in the holes.
Let set 24hr then add more and set another 24.
Hook 2 batteries up so it gets 24v and try again.
Then the breaker bar??
Try at the teeth on the flywheel.
It only needs to move 1 tooth and it might free up.

That fails? I remove one head and get a 2x4 and a 10# hammer.
That should do it.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
Your soaking the rings and for the most part that is the best you can do without taking parts of the motor off. Shrink warp is great stuff but also some of the worst stuff you can use, mostly in the summer. Air needs to be exchanged inside the boat otherwise condensation can happen. A tear in the wrap and water in the bilge just complicates it further. In the summer heat builds up and steam of sorts will start.

So the boat was in a green house for a few years and all that moisture makes everything wet, just like in a terrarium.

My guess is you need a rebuild or a long block. I would take a valve cover off and if after seeing rust, then decide.
 
Joined
Mar 30, 2010
Messages
11
It is possible the drive is locked.
Remove it and try again.
Rust on all 8 is a bad sign.
I use Marvel Mystery Oil.
Some like it others hate it??
Or diesel fuel or diesel fuel with trans fluid.
Anything even PB Blaster in the holes.
Let set 24hr then add more and set another 24.
Hook 2 batteries up so it gets 24v and try again.
Then the breaker bar??
Try at the teeth on the flywheel.
It only needs to move 1 tooth and it might free up.

That fails? I remove one head and get a 2x4 and a 10# hammer.
That should do it.

Thanks for your quick reply. I'm out of town until Saturday, but as soon as I get back I'm going to try your suggestions. I'll let you know how it goes.
 
Joined
Mar 30, 2010
Messages
11
Your soaking the rings and for the most part that is the best you can do without taking parts of the motor off. Shrink warp is great stuff but also some of the worst stuff you can use, mostly in the summer. Air needs to be exchanged inside the boat otherwise condensation can happen. A tear in the wrap and water in the bilge just complicates it further. In the summer heat builds up and steam of sorts will start.

So the boat was in a green house for a few years and all that moisture makes everything wet, just like in a terrarium.

My guess is you need a rebuild or a long block. I would take a valve cover off and if after seeing rust, then decide.
Thanks for your time and suggestions with my problem.
I will remove the valve cover on Saturday and update you with what I find.
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,758
Trying to "force" the engine to loosen up with huge breaker bars or 24 volts on the starter is a good way to break ring lands and rings. Just load it up with any lubricant or water dispersing fluid and then walk away for a few days. Now "gently" try rocking the engine back and forth ever so slightly. No movement?? Walk away for a few days. Yes -- this requires patience. Sooner or later you should get very slight movement. Then reload the cylinders and walk away. Continuing to repeat this process will produce ever increasing amounts of movement until one day, the engine will spin around fully. At this point you can attempt starting the engine but being stuck for a long period usually means the cylinders are pitted to the point where very high oil consumption will occur. This may be complicated by the fact the rings are also stuck in the ring lands in the pistons. Enter "snake oil". A product called Rislone has been around for decades (yellow can at your auto store). Add one quart in place of one quart of regular oil for an oil change and run the engine. It may take an entire summer to clean things up but it is worth a shot.
 
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