Hydrolocked? Yanmar 4JH2-TE

[IsaakOker]

Originally Posted by Geoff54

Sorry I've been busy.

So, it depends on which transmission you have.

If you have a KM4A, that has a cone clutch and it is normal to be able to move the shaft while in gear, although if it moves too easily there is probably some wear on the cone.

If you have the other type, KBWnn (i forgetthe number), it has a multi plate clutch. I don't know this trans but I don't think there is any "automatic" engagement, so I wouldn't expect that you could turn the shaft in gear. But I'm not 100% sure.

The model number is on a plate on the gear housing, on the back IIRC.

And yes, if you have a KM4A, you should sail in neutral and let the shaft spin freely, so that it doesn't wear the cone.



Good luck.

No worries, things advance very slowly here..
Hopefully tomorrow I'll take the engine out as this way I should be able to take the gearbox out easier... Still have to get hold of a bolt extractor first as I don't have one.

As for the gearbox, I have a KBW20 so as far as I would have thought is that it's mechanical and therefore I shouldn't be able to move it. But I'm not certain and can't figure it out reading the drawings on the service manual.

It's basically the same box as the kbw21 but without hardened steel.. So if anyone knows how the kbw21 works, that would be great.

I'm used WD as a penetratinf/displacing oil on bolts and mystery in the bores so I'll give it all another try tomorrow.. 🤞

Starting to feel like I need an answer to why it's not turning and what sort of work and $ we're speaking about..

Have a nice evening!

[jimbunyard]

At this point I guess it's time to ask, "how's your Karma?" or "have you made any enemies lately?"...

Really though, given what we know now it can be narrowed down to a very few things.

Based on your description, you've eliminated the transmission as a problem, at least from the internal clutch mechanism back. There is a very remote possibility that the input shaft bearing could be locked up, which would lock the engine, though the damper plate would allow a bit of movement either way.

The real 'fly in the ointment' is the speed and ease that the engine turned over in your video. With oil in the engine, spinning at that speed for that amount of time should have freed the engine and made it easier to turn, even after sitting for 2 weeks. Nor would the amount of spinning shown in the video seem to have been enough to generate enough heat to 'scuff-lock' pistons in sleeves or bearings in journals.

That leaves a frozen idler gear, very large trash in the oil pump, stuck tappets (which fall under the 'why'd it spin so well before?' category) or something stuck in the flywheel housing.

At any rate, time to stop guessing and get the engine out, because that's the only way you're gonna find out for sure.

If the companion flange bolts are a problem, often the easiest solution is a 4 1/2" grinder with a 1/16" thick cutting disc. Practice out of the boat if you haven't used one before, and watch where the sparks go, but it will make short work of deteriorated bolts.

[IsaakOker]

Originally Posted by jimbunyard

At this point I guess it's time to ask, "how's your Karma?" or "have you made any enemies lately?"...

Really though, given what we know now it can be narrowed down to a very few things.

Based on your description, you've eliminated the transmission as a problem, at least from the internal clutch mechanism back. There is a very remote possibility that the input shaft bearing could be locked up, which would lock the engine, though the damper plate would allow a bit of movement either way.

The real 'fly in the ointment' is the speed and ease that the engine turned over in your video. With oil in the engine, spinning at that speed for that amount of time should have freed the engine and made it easier to turn, even after sitting for 2 weeks. Nor would the amount of spinning shown in the video seem to have been enough to generate enough heat to 'scuff-lock' pistons in sleeves or bearings in journals.

That leaves a frozen idler gear, very large trash in the oil pump, stuck tappets (which fall under the 'why'd it spin so well before?' category) or something stuck in the flywheel housing.

At any rate, time to stop guessing and get the engine out, because that's the only way you're gonna find out for sure.

If the companion flange bolts are a problem, often the easiest solution is a 4 1/2" grinder with a 1/16" thick cutting disc. Practice out of the boat if you haven't used one before, and watch where the sparks go, but it will make short work of deteriorated bolts.

Hii Jimbunyard,

I'm going to take the karma think with a laugh hahaha
I don't remember doing anything that wrong for me to be punished with an engine that should be this stuck(obviously those sleeves are pitted and not nice but still..)

Obviously there is still a slight possibility that there's and issue with the gearbox but hopefully I'll take it off soon enough.
I'm quite experienced with angle grinders but I wanted to leave that as my last option... Prefer to have a bolt head to attach an extractor onto before even trying it..

The 7 seconds video is one of many.. We probably made it turn 7-8 times that.

I'll look into studying where and how the idler gear works but the name says quite a lot already..
Large trash has to be rather large I believe and either the engine has rusted through or there can't be that size of trash in there I hope..
The tappets might be an issue but yes, I was nearly excluding anything of the camshaft as it would be strange for it to go just this fast but I suppose things can break at any given moment.
And as for the flywheel, would be awesome that something is stuck in there without having broken it.. But I really don't know what it could be so I'll try to take this thing out tomorrow and if I have time to drain oil and take the oil sump off I'll upload more images
😴

[Geoff54]

Originally Posted by IsaakOker

I'm used WD as a penetratinf/displacing oil on bolts and mystery in the bores so I'll give it all another try tomorrow.. ��

WD40 works ok on lightly corroded stuff but PB Blaster really does work better on things that are badly rusted together. There are other products that people swear by, but I've had PB Blaster work on bolts that WD40 wouldn't budge. Tried WD40 because I'd run out of Blaster. Useless.

You'll find tests that say everything is the best. You may not believe me but here are quotes from reliable and respected sources.

Practical Sailor
"Tests found WD-40 to be best at displacing moisture, providing light lubricant and a thin film for protection, but its solvents were not as effective as others."
"PB Blaster has a strong solvent and deep chemical and capillary penetrating effect. It also contains several lubricants and leaves a thin, oily protective film. It did the best job of loosening the rusted bolts on our trailer, and so takes the top spot for this usage."

Compass Marine
"Apply penetrating oil to the shaft and coupling with PB Blaster or Thrust. Do not use WD40 or Liquid Wrench these are NOT true penetrating oils. PB Blaster or a product called Thrust are incredible products. Apply to both the prop end of the coupling and the transmission end by sliding the shaft towards the stern tube."

Do yourself a favor, go to Home Depot or the auto parts store and get some PB Blaster and use it on the bolts and the cylinders. Just keep it away from any "rubber" components.

I have no affiliation with PB Blaster and I use both products. But they are different products for different uses. BTW, I'm not a big fan of Mystery Oil either. It's a mystery to me why others use it.

Sorry for the rant! Feel free to ignore me if you like.

[IsaakOker]

Originally Posted by Geoff54

WD40 works ok on lightly corroded stuff but PB Blaster really does work better on things that are badly rusted together. There are other products that people swear by, but I've had PB Blaster work on bolts that WD40 wouldn't budge. Tried WD40 because I'd run out of Blaster. Useless.

You'll find tests that say everything is the best. You may not believe me but here are quotes from reliable and respected sources.

Practical Sailor
"Tests found WD-40 to be best at displacing moisture, providing light lubricant and a thin film for protection, but its solvents were not as effective as others."
"PB Blaster has a strong solvent and deep chemical and capillary penetrating effect. It also contains several lubricants and leaves a thin, oily protective film. It did the best job of loosening the rusted bolts on our trailer, and so takes the top spot for this usage."

Compass Marine
"Apply penetrating oil to the shaft and coupling with PB Blaster or Thrust. Do not use WD40 or Liquid Wrench these are NOT true penetrating oils. PB Blaster or a product called Thrust are incredible products. Apply to both the prop end of the coupling and the transmission end by sliding the shaft towards the stern tube."

Do yourself a favor, go to Home Depot or the auto parts store and get some PB Blaster and use it on the bolts and the cylinders. Just keep it away from any "rubber" components.

I have no affiliation with PB Blaster and I use both products. But they are different products for different uses. BTW, I'm not a big fan of Mystery Oil either. It's a mystery to me why others use it.

Sorry for the rant! Feel free to ignore me if you like.

Haha thanks!
It's not that I don't believe you but I was on the boat, bolts didn't want to move and had WD40 lying around but tomorrow I'm anyways going to buy the extractor sockets so I'll get the blaster and give it a try.

Mystery is the first time I used it and until now the pistons don't move hahaha but I'm not oging to blame it on the oil just yet 🤔

I'll update you all tomorrow & hopefully I've managed to have a look inside!

G' night!

[macaco]

I had a similar problem with a volvo aq145 gas engine, belt ran over head cam. Seized up planning accross the lake towing a wakeboarder. Wouldn't crank over, pulled head still stuck, pistons lubed still stuck, separated bell housing from the block and a mangled spring fell out. 1 of 4 springs in the damper plate fell out and seized that engine solid.
New gaskets and back on the lake,
I hope you find the issue and it's a cheap fix

[BruceS]

Getting onto the speculation stage now before the definitive answer ...!!
I'm going for hydra-locked, broken conrod & up against the block.
Screwdriver in the starter hole & lever backwards? Any movement?

[boden36]

I may be a pessimist, but a lifetime's playing with engines tells me that if someone let an engine get this bad on the outside, the chances are that it received very little care on the inside either.I expect you will find that the most economical way out of this is to purchase a good running used motor.
Regards,
Richard.

[malbert73]

Agree with replace engine probably the outcome. But the poster who suggested damper springs is really smart. I’d take apart bellhousing next. Would make sense that rust in there and you ran it, something broke after so much disuse, and is jammed in flywheel. No way cylinders are that stuck after 2 weeks. And I don’t believe you found cylinders full of water right? So unlikely hydrolock.

[a64pilot]

The KBW20 transmission has two clutch packs, one for forward the other for reverse, the gears stay engaged continuously. The clutch packs are made in such a way that engine torque presses them together to keep them from slipping so the more power the engine makes, the more firmly the packs are compressed, that also make shifting easier as the springs can be light.
Due to them not being strongly compressed when there is no engine torque may mean that with mechanical advantage the shaft can be turned with the engine off, I’ve never tried.

I believe it’s a relatively robust transmission that gives good service, but thought that the turbo 4JH motors made more power than a KBW20 could stand.

[IsaakOker]

Originally Posted by a64pilot

The KBW20 transmission has two clutch packs, one for forward the other for reverse, the gears stay engaged continuously. The clutch packs are made in such a way that engine torque presses them together to keep them from slipping so the more power the engine makes, the more firmly the packs are compressed, that also make shifting easier as the springs can be light.
Due to them not being strongly compressed when there is no engine torque may mean that with mechanical advantage the shaft can be turned with the engine off, I’ve never tried.

I believe it’s a relatively robust transmission that gives good service, but thought that the turbo 4JH motors made more power than a KBW20 could stand.

OK, makes sense.. Anyways I'm heading out now to buy a few tools and then I'll try to get this engine out..

The manual states that the turbo can go with the kbw 20/21 or km4a but the hte, dte & Ute are too strong for the kbw20.
Actually it says thst the kbw20 & km4a are the standard options for both the 4JH2E & Te & the Kbw21 is optional... Anyways, that's the one that's in here!

Let's see if there's an outcome today..

[IsaakOker]

Good evening everyone!

I finally managed to get the engine out which wasn't the easiest task but it's lying here waiting to be further taken apart tomorrow morning.

I did have a look through the gearbox sml vent and the springs seem Very rusted so that might be at least one of the issues.. Also, the mystery oil I placed in the bored seeped through a little after being in there since before yesterday I believe.

I tried taking the gearbox off and managed to get tall the bolts loose but is there 1 or 2 hidden bolts or hex underneath?
If yes, how do you remove them best because it seems to me that it's attached bit I can't easily see a bolt as such.

Have a nice eve! 👍

[jimbunyard]

Check in the parts manual

http://www.mason44.com/Linked-Files/...Searchable.pdf

under whichever gear you have. All the quantities and locations of the bolts or studs are listed.

It is very common for the splines of the transmission input shaft to get stuck in the damper plate. Some pretty vigorous prying may be necessary; if you get it started, or if you can see the input shaft through the vent, squirt some kind of lubricant in there to assist...

[IsaakOker]

Gearbox came off easily this morning & I've taken the fan and damper off too. The damper springs look quite rusted but are still on there so after trying to take the flywheel off and not managing as I don't have an impact socket wrench I'll moving to drain the oil and take the oil sump off.

The service manual states to turn the engine onto the flywheel housing, is this safe and the best way to acces the bottom without a bench?

I hope to see what's going on today because I tried moving the pistons by hammering with a mullet on a wood the same size as the pistons but I don't want to over do it & hasn't come loose yet.

[IsaakOker]

OK, bad news..

Had you all guessing for ages but I just noticed a line across 1/3rd of the flywheel.
It's a rust mark showing that the engine Had been submerged before I bought the boat.

I didn't notice it because after I had it turning 2-3 weeks ago the mark is on the starboard side and not at the bottom of the engine but it's obvious now so let's see how the inside looks after I take the sump off..