Hydrolocked? Yanmar 4JH2-TE

[a64pilot]

I don’t think I have ever seen an engine’s external condition look that bad, ever, even on old farm equipment.
Motor is going to have to come out and be overhauled in my opinion, and you need to sit down when you find out the cost, it may be that it’s not worth it, boat wise.
This is I guess when you decide to cut bait or go all in, but if you had dreams of cosmetic clean ups, that isn’t going to happen, this is major $$$.
Not trying to be a buzz kill, but trying to be the voice of reality. This isn’t going to be cheap, not being a turbo and all.

[Geoff54]

RE: my last post. You will need to scrape the carbon out of the top of the bores before you pull the pistons through the top.

[IsaakOker]

Originally Posted by a64pilot

I don’t think I have ever seen an engine’s external condition look that bad, ever, even on old farm equipment.
Motor is going to have to come out and be overhauled in my opinion, and you need to sit down when you find out the cost, it may be that it’s not worth it, boat wise.
This is I guess when you decide to cut bait or go all in, but if you had dreams of cosmetic clean ups, that isn’t going to happen, this is major $$$.
Not trying to be a buzz kill, but trying to be the voice of reality. This isn’t going to be cheap, not being a turbo and all.

Well I'm conscious about the fact that it will be close in time+money =buy a REMAN or so.
Don't worry, I'm fine with reality as long as there is one.. What I don't like is not knowing.

I'll probably be pulling the engine out tomorrow and will drain the oil & turn it over to see what the real state is but first I'll try to take the gearbox off, turn the shaft, clean the top end of cylinders as much as I can and see what I get.

I have a lot of faith in repairing things rather than replacing so if it's possible it's highly likely I go all in.. But too early to say.

[Geoff54]

Originally Posted by a64pilot

I don’t think I have ever seen an engine’s external condition look that bad, ever, even on old farm equipment.
Motor is going to have to come out and be overhauled in my opinion, and you need to sit down when you find out the cost, it may be that it’s not worth it, boat wise.
This is I guess when you decide to cut bait or go all in, but if you had dreams of cosmetic clean ups, that isn’t going to happen, this is major $$$.
Not trying to be a buzz kill, but trying to be the voice of reality. This isn’t going to be cheap, not being a turbo and all.

The outside does look bad but that's only the outside and we can't really tell the rest until it is all apart. We can see that the top end doesn't look terrible and the 4JH bottom end is robust, so he might be lucky.

For reference, when I did my top end in 2016, rings, valves, valve guides, gaskets, seals, all new hoses, big end shells (just because I had them apart) came to about $1000. In that the big and small ends were perfect and the end play was spot on, I didn't even touch the crank. Admittedly I had all the tools that I needed and the op is going to have to borrow or buy a few things, but I'm betting he can get this engine up and running for a lot less than replacing it. Hopefully the big ticket items like the heat exchanger and turbo are serviceable.

And he's got the right attitude to sort this out. Good on him!

[Empty Pockets]

Originally Posted by IsaakOker

Yes, the boat was in GA on a lake, 5 yrs locked up.
:

We’ve pulled airplanes off the bottom of lakes and gotten the he engines going again. Either something happened in the bottom end that you haven’t found yet, or I’ll suggest a bigger breaker bar or someone who’s done this before to help you turn it. Don’t be afraid of how hard you may need to pull to break it free. A 1/2 inch drive ratchet without 2-3 feet of breaker bar on it is unlikely to do it. Like others have said, make sure you’re in neutral, and PULL!

[sailah]

Man I got a hard time believing an engine that cranked over that easy in the video now 2 weeks later is completely seized in fresh water. I don't know what the answer is but I'm surprised you can't get any action from the crank bolt esp with the head off and no compression. Were the bores filled with water when you removed head?

[boatbod]

Water + iron/steel + air = rust.
If you can't bar the engine over you're going to have to pull it and either replace or rebuild on the bench. Perhaps if you remove the head, oil pan and crankshaft you can pound on the pistons and break the seized rings loose.

[Wotname]

Originally Posted by a64pilot

Usually #1 is the front of an engine, the end without the flywheel.

Yanmar number the cylinders on these small boat engines from the gearbox / flywheel end. I don't why but believe it is marine or big ship thing.

Originally Posted by sailah

Man I got a hard time believing an engine that cranked over that easy in the video now 2 weeks later is completely seized in fresh water. I don't know what the answer is but I'm surprised you can't get any action from the crank bolt esp with the head off and no compression. Were the bores filled with water when you removed head?

Yes, I'm amazed that it could seize so tight inside 2 weeks but didn't seize in the previous 5 years - I can't help wondering if there must be something else stoping it move.

Likewise with the starter motor, it worked OK 2weeks ago and is now not OK.

[a64pilot]

Originally Posted by Wotname

Yanmar number the cylinders on these small boat engines from the gearbox / flywheel end. I don't why but believe it is marine or big ship thing

I can believe that, Ford I think numbers it’s cylinders differently than GM too, not sure as I don’t work on Fords.
Lycoming and Continental also number their engines differently from each other. There seems to be no logic

[IsaakOker]

Originally Posted by Geoff54

The outside does look bad but that's only the outside and we can't really tell the rest until it is all apart. We can see that the top end doesn't look terrible and the 4JH bottom end is robust, so he might be lucky.

For reference, when I did my top end in 2016, rings, valves, valve guides, gaskets, seals, all new hoses, big end shells (just because I had them apart) came to about $1000. In that the big and small ends were perfect and the end play was spot on, I didn't even touch the crank. Admittedly I had all the tools that I needed and the op is going to have to borrow or buy a few things, but I'm betting he can get this engine up and running for a lot less than replacing it. Hopefully the big ticket items like the heat exchanger and turbo are serviceable.

And he's got the right attitude to sort this out. Good on him!

Thanks very much for the encouragement!
I'll keep in going and tomorrow we'll see if I can pull the engine and find the issue.. I think it's time as it will take ages to get this fixed - if possible -.

I've just uploaded a few more images so after I answer to the individual posts I'll put the link through.

Thanks for the rough cost estimate you had a few years back.. I'm also hoping that heat exchanger and turbo are serviceable as that would blow the cost very much...

[IsaakOker]

Originally Posted by Empty Pockets

We’ve pulled airplanes off the bottom of lakes and gotten the he engines going again. Either something happened in the bottom end that you haven’t found yet, or I’ll suggest a bigger breaker bar or someone who’s done this before to help you turn it. Don’t be afraid of how hard you may need to pull to break it free. A 1/2 inch drive ratchet without 2-3 feet of breaker bar on it is unlikely to do it. Like others have said, make sure you’re in neutral, and PULL!

Haha I'm sure this engine can be brought back to life.. The matter is how much $.

I've got a 1.5m(5ft) ss tube on the end of the socket wrench and nothing.. I think something must be blocking it..

[IsaakOker]

Originally Posted by sailah

Man I got a hard time believing an engine that cranked over that easy in the video now 2 weeks later is completely seized in fresh water. I don't know what the answer is but I'm surprised you can't get any action from the crank bolt esp with the head off and no compression. Were the bores filled with water when you removed head?

Hi Sailah,
As I've said before, I'm also very much impressed but that's the truth.. It was turning, I saw it with my own eyes hahah.

I do see multiple different marks in the cylinders so it definitely looks like it was locked up before.

Tmthere was a mix of cooland and the oil I poured in through the injector holes. Not sure if the coolant was from lifting the head though.. The mix wasn't while yet.

[IsaakOker]

Originally Posted by Wotname

Yanmar number the cylinders on these small boat engines from the gearbox / flywheel end. I don't why but believe it is marine or big ship thing.


Yes, I'm amazed that it could seize so tight inside 2 weeks but didn't seize in the previous 5 years - I can't help wondering if there must be something else stoping it move.

Likewise with the starter motor, it worked OK 2weeks ago and is now not OK.

I've just checked the gear box and I can't move the shaft no matter if it's engaged or in neutral so maybe there's my issue... Will be for tomorrow!

Thanks for your imput and I'm also really amazed. I want an answer to not be guessing anymore

[IsaakOker]

So, I hope I've managed to reply to everyone's feedback

I've tried cleaning the rust off a bit and specially dryed them out as much as possible & filled them with oil.
I haven't gone crazy cleaning them as they're damaged and not sure yet if I can salvage the engine so didn't want to dive in too deep.

I've tried to turn the shaft engaging and disengaging the gearbox and although it seems to be doing something, the shaft won't move. It has a 1/8th of a turn play which is probably just a minor gearbox output issue.

I'll take the engine out tomorrow I hope and once the gearbox is de-attached I'll try again at the crankshaft.

I've uploaded the images into the folder "Cylinders" linked below. I also cleaned the outside a little so that It doesn't scare us all away 🤔

https://ibb.co/album/c3ASWF

Have a great day/evening and thanks for all your time to answer and will to help out! Very much appreciated 👌

[unbusted67]

Originally Posted by IsaakOker

So, I hope I've managed to reply to everyone's feedback

I've tried cleaning the rust off a bit and specially dryed them out as much as possible & filled them with oil.
I haven't gone crazy cleaning them as they're damaged and not sure yet if I can salvage the engine so didn't want to dive in too deep.

I've tried to turn the shaft engaging and disengaging the gearbox and although it seems to be doing something, the shaft won't move. It has a 1/8th of a turn play which is probably just a minor gearbox output issue.

I'll take the engine out tomorrow I hope and once the gearbox is de-attached I'll try again at the crankshaft.

I've uploaded the images into the folder "Cylinders" linked below. I also cleaned the outside a little so that It doesn't scare us all away 🤔

https://ibb.co/album/c3ASWF

Have a great day/evening and thanks for all your time to answer and will to help out! Very much appreciated 👌

Well, wait. Then that's your answer. Don't pull the engine. Just pull the trans.

I just had a similar problem on a volvo MD17C and I wasn't able to get it going again. 12k for a new motor. yay.