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Advised by many not to rebuild YSE8! Why? New engine doesn't fit.

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Created by Serb1980 > 9 months ago, 11 Apr 2022
Serb1980
388 posts
11 Apr 2022 8:00PM
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Hi there
did some of you ever rebuilt your yse8? How long they worked fine? I need 4 k to accommodate a new engine, (plus new engine 11k I am on 15k here)it's just not worth the money. Why so many mechanics are saying that reconditioned YSE 8 will only last year or two if I am lucky?

I need help here

shaggybaxter
QLD, 2645 posts
11 Apr 2022 11:21PM
Thumbs Up

Hiya Serb,
If they haven't inspected your motor they are generalizing. Yachties have a pretty terrible track record at maintaining iron engines so its usually a pretty safe position to take.
The only thing I could imagine that would justify such a prediction would be the water jackets in the block are so corroded they are near penetrating cylinder walls or oil galleries. Which you'd normally need the head off as a minimum to diagnose properly.
Alternately, if they have looked at the engine, it's obvious you have some major issue, and they've done some analysis then that's a bit different.
To find out if it's toast, just get it pulled or pull the head off and have a good look. Either or is still a step in the right direction and will give you the info you need to make a call.
If its not screwed beyond repair, personally I would definitely recondition it.

Ramona
NSW, 7732 posts
12 Apr 2022 8:29AM
Thumbs Up

Recondition it yourself.

woko
NSW, 1757 posts
12 Apr 2022 8:53AM
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If the crank, engine block & head are serviceable A quick search found a rebuild kit $ 1880.00 assume US $ + freight so you could double that. As Ramona said buy some tools and do it yourself. You will still have a vintage motor and no warranty, it's easy to see why the outboard is a common solution. $14k for an engine upgrade you might as well go electric and modernise the vessel


Serb1980
388 posts
12 Apr 2022 7:17AM
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woko said..
If the crank, engine block & head are serviceable A quick search found a rebuild kit $ 1880.00 assume US $ + freight so you could double that. As Ramona said buy some tools and do it yourself. You will still have a vintage motor and no warranty, it's easy to see why the outboard is a common solution. $14k for an engine upgrade you might as well go electric and modernise the vessel



Thanks for this. Really appreciate

garymalmgren
1353 posts
12 Apr 2022 7:24AM
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Hi Serb
I have been following your adventures with the little Yanmar and I am still left with one question.

What is wrong with it?

Simple short answer please.

gary

cammd
QLD, 4289 posts
12 Apr 2022 11:08AM
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Select to expand quote
garymalmgren said..
Hi Serb
I have been following your adventures with the little Yanmar and I am still left with one question.

What is wrong with it?

Simple short answer please.

gary



won't reach hull speed!

Mike367
VIC, 150 posts
12 Apr 2022 6:42PM
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Select to expand quote
cammd said..

garymalmgren said..
Hi Serb
I have been following your adventures with the little Yanmar and I am still left with one question.

What is wrong with it?

Simple short answer please.

gary




won't reach hull speed!


So the engine actually runs okay?

woko
NSW, 1757 posts
12 Apr 2022 7:11PM
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Na, it runs but from one of the other dozen threads about it, it can't run an alternator after decarbonisation treatment.

stray
SA, 325 posts
12 Apr 2022 7:22PM
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Mc Greggor 26 would solve this problem.
Bracing.

Jolene
WA, 1620 posts
12 Apr 2022 8:31PM
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Mc Greggors are awesome,
Yet to see a Mc Greggor owner that ain't having fun,,

Achernar
QLD, 395 posts
13 Apr 2022 8:23PM
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Serb1980 said..
Hi there
did some of you ever rebuilt your yse8? How long they worked fine? I need 4 k to accommodate a new engine, (plus new engine 11k I am on 15k here)it's just not worth the money. Why so many mechanics are saying that reconditioned YSE 8 will only last year or two if I am lucky?

I need help here


IMO, a reconditioned engine might last a year and it might last ten years.

Speaking as someone who hopes to get a reconditioned engine back into the boat after a 5-month project, my perspective is this ...

* The engine itself might only account for part of the cost and effort of a refit, depending on the state of all the other stuff you need. In my case, the lengthiest, most difficult issue was rebuilding the engine beds. I have previously mentioned the peripherals. I have yet to get to my electrics which may, or may not, need to be replaced. The bare minimum will be a new start and stop switch assembly. I also intend to replace the sea-cocks. I also intend to do lots of other stuff that I will probably never get round to doing.

* Reconditioning your existing engine allows you to address all the "other necessary stuff" one at a time, rather than having to do it in a single job, which means you can spread the cost over a longer period. The advantage is that you can avoid that awkward conversation that starts with "I thought you said it would be $10K, but it is now $15K". The disadvantage is that you might see some of the money "wasted" on buying stuff that you did not really need, or stuff that you need to replace, again, because it does not fit the "final" version of your engine. For example, I bought new bearings and a polyflex coupling for about $900. If I need to buy a new engine, these new bearings might not fit, or the supplier might insist on replacing them, which means I would have lost $900 (incidentally, the quotes for new engines usually include new bearings).

* There are plenty of unknowns and risks in re-powering your boat. It might go well, in which case the initial budget of $15K would have been way too much. I suggest that $15K is a reasonable upper limit, allowing for things to go badly. If you can bring it in for $5K, you'll be a happy bunny, and so will your Minister of Finance/Admiral.

Considering all the opportunities, risks and unknowns, my recommendation is to recondition the old engine, and work through the problems as they arise, one by one. If the reconditioned engine lasts only a year, you would have had a year to fix up all the things you needed to fix before getting a new engine, or a new-reconditioned-old-engine, or whatever. If it blows up on the first day, you would have lost, say $3K, but you would have a really good reason to get a new engine. If it lasts 10 years, you would have 10 years' experience and knowledge to guide you in your next decision.

You seem to be quite handy with the tools. The reconditioned engine will give you the opportunity to get in there and trouble-shoot and fix stuff yourself. The education and experience this will bring might be the most valuable thing you get from this venture.

Serb1980
388 posts
13 Apr 2022 9:13PM
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garymalmgren said..
Hi Serb
I have been following your adventures with the little Yanmar and I am still left with one question.

What is wrong with it?

Simple short answer please.

gary


1) It blows more smoke from crankshaft valve that exhaust.
2) loss of compression ( can not turn if alternator is connected 30Amp)
3) something wrong with valves
4) possible head gasket damage and water leak

Tomorrow going to remove head out and put a new head gasket and fix the valve set up 2mil clearance.
will keep update

Serb1980
388 posts
13 Apr 2022 9:23PM
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Ramona said..
Recondition it yourself.


Started the process. Always get a rod lost in chankshaft block. I have an incomplete spare yse8 and when observing the valve rodes on yse8 it's clear where to position them. They can not disappear in the block. YSE is different, rodes always disappears then I need to remove chrank shaft valve door and search for those rodes inside of engine block full of oil. A very frustrated job.

FabulousPhill
VIC, 320 posts
13 Apr 2022 11:49PM
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Lapping the valves and valve seats will solve some/most of the compression issue, unless it is the piston, but worth checking. Simple, cheap and quick to lap them, YouTube will instruct you.
Then you will need the head off, check it for any cracks, or calcium build up, that it is dead flat, etc, and then a new head gasket, and the bolts replaced using a torque wrench.
The YSE motors have comprehensive service manuals online, to which you can download for free and print out.

garymalmgren
1353 posts
13 Apr 2022 10:21PM
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Re Arch;
IMO, a reconditioned engine might last a year and it might last ten years.

When I was a port engineer in Singapore we had a workshop in Loyang where we reconditioned Detroit diesels back to AS NEW condition.
In the Diesel workshop at Port Hedland where I worked for the Mt Newman Mining Co we reconditioned diesel electric locomotive engines and expected 1,000,000 mile from them.
A diesel engine can be reconditioned to as new condition and any expectation of a year points to poor workmanship.

As an aside on the S.V, Sea Investigator in the Red Sea I served alongside Hans Diesel, the great grand son of the inventor of the diesel engine. Not relevant , I know.

My YSE Yanmar was retrieved from a vessel that went down in the Japanese tsunami. It was recovered with the crankcase half full of sand and the other half full of mud. It is now in as new condition.

Re Sreb,
Always get a rod lost in chankshaft block
What on earth are you talking about?
Here is how it is done,

Gary

woko
NSW, 1757 posts
14 Apr 2022 7:14AM
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Well said Gary, I think this thread stems from the modern chuck it and get a new one mentality, also interesting that you worked along side Hans diesel strangely symbiotic, I was recently reading about his great grand fathers engine and that it was designed to run on peanut oil, looks like bio fuel has taken us back to the beginning

shaggybaxter
QLD, 2645 posts
14 Apr 2022 8:15AM
Thumbs Up

Select to expand quote
garymalmgren said..
Re Arch;
IMO, a reconditioned engine might last a year and it might last ten years.

When I was a port engineer in Singapore we had a workshop in Loyang where we reconditioned Detroit diesels back to AS NEW condition.
In the Diesel workshop at Port Hedland where I worked for the Mt Newman Mining Co we reconditioned diesel electric locomotive engines and expected 1,000,000 mile from them.
A diesel engine can be reconditioned to as new condition and any expectation of a year points to poor workmanship.

As an aside on the S.V, Sea Investigator in the Red Sea I served alongside Hans Diesel, the great grand son of the inventor of the diesel engine. Not relevant , I know.

My YSE Yanmar was retrieved from a vessel that went down in the Japanese tsunami. It was recovered with the crankcase half full of sand and the other half full of mud. It is now in as new condition.

Re Sreb,
Always get a rod lost in chankshaft block
What on earth are you talking about?
Here is how it is done,

Gary


Nice video Gary, that was strangely interesting to watch. Good example of diesel knock! I used to think that was just lazy clearances till mate explained how fuels like diesel that are good for using compression as the ignition source also means their anti knock properties will suck .
I still find it amazing how knocking isn't bad in a diesel engine but it's the harbinger of death in a petrol engine.

Serb1980
388 posts
14 Apr 2022 2:03PM
Thumbs Up

Select to expand quote
garymalmgren said..
Re Arch;
IMO, a reconditioned engine might last a year and it might last ten years.

When I was a port engineer in Singapore we had a workshop in Loyang where we reconditioned Detroit diesels back to AS NEW condition.
In the Diesel workshop at Port Hedland where I worked for the Mt Newman Mining Co we reconditioned diesel electric locomotive engines and expected 1,000,000 mile from them.
A diesel engine can be reconditioned to as new condition and any expectation of a year points to poor workmanship.

As an aside on the S.V, Sea Investigator in the Red Sea I served alongside Hans Diesel, the great grand son of the inventor of the diesel engine. Not relevant , I know.

My YSE Yanmar was retrieved from a vessel that went down in the Japanese tsunami. It was recovered with the crankcase half full of sand and the other half full of mud. It is now in as new condition.

Re Sreb,
Always get a rod lost in chankshaft block
What on earth are you talking about?
Here is how it is done,

Gary


This morning fixed valves rods, changed head gasket (made my self from aluminium)made a casket for a crankshaft breather cover and my Hans is back.
Not start I used a cigaret lighter to produce a hot air in the intake and it started. Works like a sawing machine. Still showing some blow by from a crankshaft breather. I am wondering how to check if is stuck piston ring or damaged piston rings?
Glad I got my baby back. I love YSE8. It's just like a solid rock!

Serb1980
388 posts
14 Apr 2022 2:13PM
Thumbs Up

Select to expand quote
garymalmgren said..
Re Arch;
IMO, a reconditioned engine might last a year and it might last ten years.

When I was a port engineer in Singapore we had a workshop in Loyang where we reconditioned Detroit diesels back to AS NEW condition.
In the Diesel workshop at Port Hedland where I worked for the Mt Newman Mining Co we reconditioned diesel electric locomotive engines and expected 1,000,000 mile from them.
A diesel engine can be reconditioned to as new condition and any expectation of a year points to poor workmanship.

As an aside on the S.V, Sea Investigator in the Red Sea I served alongside Hans Diesel, the great grand son of the inventor of the diesel engine. Not relevant , I know.

My YSE Yanmar was retrieved from a vessel that went down in the Japanese tsunami. It was recovered with the crankcase half full of sand and the other half full of mud. It is now in as new condition.

Re Sreb,
Always get a rod lost in chankshaft block
What on earth are you talking about?
Here is how it is done,

Gary


This morning fixed valves rods, changed head gasket (made my self from aluminium)made a casket for a crankshaft breather cover and my Hans is back.
Not start I used a cigaret lighter to produce a hot air in the intake and it started. Works like a sawing machine. Still showing some blow by from a crankshaft breather. I am wondering how to check if is stuck piston ring or damaged piston rings?
Glad I got my baby back. I love YSE8. It's just like a solid rock!

herec is the picture of fixing gasket ( used motorcycle one)



UncleBob
NSW, 1299 posts
14 Apr 2022 5:04PM
Thumbs Up

Select to expand quote
Serb1980 said..

garymalmgren said..
Re Arch;
IMO, a reconditioned engine might last a year and it might last ten years.

When I was a port engineer in Singapore we had a workshop in Loyang where we reconditioned Detroit diesels back to AS NEW condition.
In the Diesel workshop at Port Hedland where I worked for the Mt Newman Mining Co we reconditioned diesel electric locomotive engines and expected 1,000,000 mile from them.
A diesel engine can be reconditioned to as new condition and any expectation of a year points to poor workmanship.

As an aside on the S.V, Sea Investigator in the Red Sea I served alongside Hans Diesel, the great grand son of the inventor of the diesel engine. Not relevant , I know.

My YSE Yanmar was retrieved from a vessel that went down in the Japanese tsunami. It was recovered with the crankcase half full of sand and the other half full of mud. It is now in as new condition.

Re Sreb,
Always get a rod lost in chankshaft block
What on earth are you talking about?
Here is how it is done,

Gary



This morning fixed valves rods, changed head gasket (made my self from aluminium)made a casket for a crankshaft breather cover and my Hans is back.
Not start I used a cigaret lighter to produce a hot air in the intake and it started. Works like a sawing machine. Still showing some blow by from a crankshaft breather. I am wondering how to check if is stuck piston ring or damaged piston rings?
Glad I got my baby back. I love YSE8. It's just like a solid rock!


You fitted a homemade aluminium head gasket?? good luck and please do let us know how it works out.

woko
NSW, 1757 posts
14 Apr 2022 5:54PM
Thumbs Up

Select to expand quote
shaggybaxter said..

garymalmgren said..
Re Arch;
IMO, a reconditioned engine might last a year and it might last ten years.

When I was a port engineer in Singapore we had a workshop in Loyang where we reconditioned Detroit diesels back to AS NEW condition.
In the Diesel workshop at Port Hedland where I worked for the Mt Newman Mining Co we reconditioned diesel electric locomotive engines and expected 1,000,000 mile from them.
A diesel engine can be reconditioned to as new condition and any expectation of a year points to poor workmanship.

As an aside on the S.V, Sea Investigator in the Red Sea I served alongside Hans Diesel, the great grand son of the inventor of the diesel engine. Not relevant , I know.

My YSE Yanmar was retrieved from a vessel that went down in the Japanese tsunami. It was recovered with the crankcase half full of sand and the other half full of mud. It is now in as new condition.

Re Sreb,
Always get a rod lost in chankshaft block
What on earth are you talking about?
Here is how it is done,

Gary



Nice video Gary, that was strangely interesting to watch. Good example of diesel knock! I used to think that was just lazy clearances till mate explained how fuels like diesel that are good for using compression as the ignition source also means their anti knock properties will suck .
I still find it amazing how knocking isn't bad in a diesel engine but it's the harbinger of death in a petrol engine.


Shaggy you've never heard an engine knock until you've heard a Commer horizontally opposed, aka the commer knocker, a strange 2 stroke beast that had two pistons per cylinder a crank at either end and the pistons nearly met in the middle, I was told it was because of British road tax at the time was charged per cylinder. It just goes to show what can be done in the world of engineering. Students on my training vessel that have modern motor knowledge are gobsmacked that her Detroit engine is a 2 stroke.

tarquin1
954 posts
14 Apr 2022 4:31PM
Thumbs Up

I had a quick look and an official Yanmar head gasket is about 35 euros, in France. Cant imagine they are hard to get or that much more expensive in Oz. Why would you make your own? Be interested to see what Gary thinks.

Bananabender
QLD, 1610 posts
14 Apr 2022 6:33PM
Thumbs Up

I know all about knocking. First car was a 1946 Studebaker for 52 quid. Coming back from surfing trip a knocking noise came from engine . Brother suggested I speed up to see if it goes away . It did , hole threw side of block.

Kinora
VIC, 187 posts
14 Apr 2022 8:01PM
Thumbs Up

Select to expand quote
woko said..

shaggybaxter said..


garymalmgren said..
Re Arch;
IMO, a reconditioned engine might last a year and it might last ten years.

When I was a port engineer in Singapore we had a workshop in Loyang where we reconditioned Detroit diesels back to AS NEW condition.
In the Diesel workshop at Port Hedland where I worked for the Mt Newman Mining Co we reconditioned diesel electric locomotive engines and expected 1,000,000 mile from them.
A diesel engine can be reconditioned to as new condition and any expectation of a year points to poor workmanship.

As an aside on the S.V, Sea Investigator in the Red Sea I served alongside Hans Diesel, the great grand son of the inventor of the diesel engine. Not relevant , I know.

My YSE Yanmar was retrieved from a vessel that went down in the Japanese tsunami. It was recovered with the crankcase half full of sand and the other half full of mud. It is now in as new condition.

Re Sreb,
Always get a rod lost in chankshaft block
What on earth are you talking about?
Here is how it is done,

Gary




Nice video Gary, that was strangely interesting to watch. Good example of diesel knock! I used to think that was just lazy clearances till mate explained how fuels like diesel that are good for using compression as the ignition source also means their anti knock properties will suck .
I still find it amazing how knocking isn't bad in a diesel engine but it's the harbinger of death in a petrol engine.



Shaggy you've never heard an engine knock until you've heard a Commer horizontally opposed, aka the commer knocker, a strange 2 stroke beast that had two pistons per cylinder a crank at either end and the pistons nearly met in the middle, I was told it was because of British road tax at the time was charged per cylinder. It just goes to show what can be done in the world of engineering. Students on my training vessel that have modern motor knowledge are gobsmacked that her Detroit engine is a 2 stroke.


Hi Woko, the British engine firm Napier took that concept a long way, see en.wikipedia.org/wiki/Napier_Deltic.

r13
NSW, 1712 posts
14 Apr 2022 8:53PM
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this is the link - without the full stop

en.wikipedia.org/wiki/Napier_Deltic

Serb1980
388 posts
14 Apr 2022 7:13PM
Thumbs Up

Select to expand quote
UncleBob said..

Serb1980 said..


garymalmgren said..
Re Arch;
IMO, a reconditioned engine might last a year and it might last ten years.

When I was a port engineer in Singapore we had a workshop in Loyang where we reconditioned Detroit diesels back to AS NEW condition.
In the Diesel workshop at Port Hedland where I worked for the Mt Newman Mining Co we reconditioned diesel electric locomotive engines and expected 1,000,000 mile from them.
A diesel engine can be reconditioned to as new condition and any expectation of a year points to poor workmanship.

As an aside on the S.V, Sea Investigator in the Red Sea I served alongside Hans Diesel, the great grand son of the inventor of the diesel engine. Not relevant , I know.

My YSE Yanmar was retrieved from a vessel that went down in the Japanese tsunami. It was recovered with the crankcase half full of sand and the other half full of mud. It is now in as new condition.

Re Sreb,
Always get a rod lost in chankshaft block
What on earth are you talking about?
Here is how it is done,

Gary




This morning fixed valves rods, changed head gasket (made my self from aluminium)made a casket for a crankshaft breather cover and my Hans is back.
Not start I used a cigaret lighter to produce a hot air in the intake and it started. Works like a sawing machine. Still showing some blow by from a crankshaft breather. I am wondering how to check if is stuck piston ring or damaged piston rings?
Glad I got my baby back. I love YSE8. It's just like a solid rock!



You fitted a homemade aluminium head gasket?? good luck and please do let us know how it works out.


So far so good! Engine is mad oil is leaking everywhere when revs on full throttle.. Must fix leakage on the crankshaft valve breather cover. Two bolts went broken .. Very bad .. I will try to put some special silicone hope it will stop the leakage. otherwise very please with results. I hope was just a stuck ring. Left engine idling all day no blue or white smoke . compression is back. Starts and turns both pump and alternator without any issues.

Keep in touch

Kinora
VIC, 187 posts
14 Apr 2022 9:18PM
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Select to expand quote
r13 said..
this is the link - without the full stop

en.wikipedia.org/wiki/Napier_Deltic


Thanks, r13. I plead an old school education and the consequent compulsion to use punctuation.

Serb1980
388 posts
14 Apr 2022 7:44PM
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Select to expand quote
tarquin1 said..
I had a quick look and an official Yanmar head gasket is about 35 euros, in France. Cant imagine they are hard to get or that much more expensive in Oz. Why would you make your own? Be interested to see what Gary thinks.


Like to make my own things. Experiment a bit!Learn, observe, improve ... this boat is my toy, eventually in a couple of years more modern and luxurious Hense is coming and than everything will be on buttons but till then love to play with engine parts etc..

see picture..






garymalmgren
1353 posts
14 Apr 2022 9:22PM
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Hi Serb I realize that English may not be your native tongue and respect you for giving it a go. However it seems that you don't read or are ignoring most of the good advice that has been posted to you. (see Fabulous Phil's comments about valve lapping)
You have to be methodical. You cannot jump from one idea to another without a logical bridge.
Where to start? I guess I will start with my question about your engine?
What is wrong with it?
Simple short answer please.


Next, where you are, how you got there and where you would like to go.
You mention "This morning fixed valves rods, changed head gasket (made my self from aluminium)made a casket for a crankshaft breather cover and my Hans is back. "
I take this to mean that you have had the head off and had trouble refitting the valve push rods. When you had the head off did you check the valve guides and the valve condition. The video that I posted on a rebuild clearly shows how to assemble and reassemble the valve gear. If the valve guides are worn you will get blow by of gases into the rocker cover then down the push rod galleries which can pressurize you crankcase. If you didn't check you have wasted the head removal.
When you had the head off did you rotate the piston so it was at the bottom of the stroke and check the condition of the bore? If you didn't check you have wasted the head removal.
Re
herec is the picture of fixing gasket ( used motorcycle one)

Are you honestly saying that you got a Suzuki motorcycle barrel to crankcase gasket, cut it into little pieces and superglued it to the crankcase breather housing? You expect this to be a good oil seal with all of those gaps and joints? Sorry. No way.

You last post shows a disassembled YS engine. I am guessing that is your spare.
Your original question was
Advised by many not to rebuild YSE8! Why? New engine doesn't fit.
No one here advised you not to rebuild.

So I recommend that you rebuild the engine that you have in bits.
If you have bothered to watch the vid on the rebuild that I posted you will notice that the only (obvious) new parts were big end bearings and rings.
You can rebuild a Yanmar with bearings and seals from a normal supplier. Just take your old ones in a drop them on the counter.
You can make new gaskets (except an aluminuim head gasket) and a rebuild can be done for less than $500.
That is the glory of the YSE.

To rebuild, from Yanmar you will need a head gasket.
Rings.
Small end bearings. big end bearings.
And maybe valve guides. And gudgeon pin.
As I said all other parts can be got very cheaply.

Your home made aluminum head gasket will corrode quite fast and allow sea water to enter the barrel.
Buy a new head gasket and fit it.
When you have the head off to do that, check the valves and guides (as the vid shows) and check the bore.
I have already posted links to the parts list and the manual , but I have a feeling that you haven't downloaded them yet.


Gary


Serb1980
388 posts
14 Apr 2022 9:57PM
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Select to expand quote
garymalmgren said..
Hi Serb I realize that English may not be your native tongue and respect you for giving it a go. However it seems that you don't read or are ignoring most of the good advice that has been posted to you. (see Fabulous Phil's comments about valve lapping)
You have to be methodical. You cannot jump from one idea to another without a logical bridge.
Where to start? I guess I will start with my question about your engine?
What is wrong with it?
Simple short answer please.


Next, where you are, how you got there and where you would like to go.
You mention "This morning fixed valves rods, changed head gasket (made my self from aluminium)made a casket for a crankshaft breather cover and my Hans is back. "
I take this to mean that you have had the head off and had trouble refitting the valve push rods. When you had the head off did you check the valve guides and the valve condition. The video that I posted on a rebuild clearly shows how to assemble and reassemble the valve gear. If the valve guides are worn you will get blow by of gases into the rocker cover then down the push rod galleries which can pressurize you crankcase. If you didn't check you have wasted the head removal.
When you had the head off did you rotate the piston so it was at the bottom of the stroke and check the condition of the bore? If you didn't check you have wasted the head removal.
Re
herec is the picture of fixing gasket ( used motorcycle one)

Are you honestly saying that you got a Suzuki motorcycle barrel to crankcase gasket, cut it into little pieces and superglued it to the crankcase breather housing? You expect this to be a good oil seal with all of those gaps and joints? Sorry. No way.

You last post shows a disassembled YS engine. I am guessing that is your spare.
Your original question was
Advised by many not to rebuild YSE8! Why? New engine doesn't fit.
No one here advised you not to rebuild.

So I recommend that you rebuild the engine that you have in bits.
If you have bothered to watch the vid on the rebuild that I posted you will notice that the only (obvious) new parts were big end bearings and rings.
You can rebuild a Yanmar with bearings and seals from a normal supplier. Just take your old ones in a drop them on the counter.
You can make new gaskets (except an aluminuim head gasket) and a rebuild can be done for less than $500.
That is the glory of the YSE.

To rebuild, from Yanmar you will need a head gasket.
Rings.
Small end bearings. big end bearings.
And maybe valve guides. And gudgeon pin.
As I said all other parts can be got very cheaply.

Your home made aluminum head gasket will corrode quite fast and allow sea water to enter the barrel.
Buy a new head gasket and fit it.
When you have the head off to do that, check the valves and guides (as the vid shows) and check the bore.
I have already posted links to the parts list and the manual , but I have a feeling that you haven't downloaded them yet.


Gary





Thanks Gary

This morning was just an experiment if the beast will start. I wasn't expecting that engine will start honestly. Yes, I was advised by almost every and each mechanic in Sydney to not rebuild my YSE because they are trying to sell beta or nanni to me. For many the engine was beyond the repair! I knew that something is wrong because they didn't even see the engine but they saying to get a new one. Only one mechanic who will rebuild it sad that Yanmar made marine engines while kubota made tractors! I liked the comment! when it comes to rebuild it, it will go to the mechanic. I don't have that confidence and knowledge to do it. Now I can charge my batteries and when engine is hot try to go around a bit. I am wondering now when compression is back will engine pull a hull speed? Mechanics are all busy and it will take time to rebuild mine. In the meantime happy to observe what is going on and how engine is behaving. Today I was using a mirror and torch for most of the work. Space is limited. When I opened the valve cover I found rods dropped completely disconnected from the rockers.
Anyway eventually the engine must be pulled out of the boat and everything checked and fixed properly. If needed engine must start immediately and pull the hull speed when I get in trouble. For that reason a mechanic will do ALL this work ( cylinder, pistons, rings .etc.). Even if engine start to behave normally I will make sure that mechanic check everything from scratch. It's always better to be safe than sorry.
I love to open things and learn how and why things are moving in such way but when it comes to rebuild the engine from scratch, that requires some serious skills which I don't have. That is the fact! Joke a part now! So far managed to get the engine back to business and I am proud of myself and you guys. YSE is a very solid engine and I have changed my mind. Volvo penta is nice engine but Yanmar is something mad. Actually I can say bulletproof. That would be it from me. I will keep charging batteries for a month and than take my Tasman with YSE8 and a spare YSB8 to the mechanic who will eventually rebuild it and make one perfect engine. Till my new Hense 315 comes I will be enjoying my little Yanmar and crazy Tasman around the heads. Once the process is done I will make a photo of every single part that is left from both engines and offer them for free if any of you guys are in needs. I know that parts are old and not easy to find any more.The day I sell my Tasman the new owner will have proof that engine is professional done so he can be a problem free for some times. If I try to rebuild it he might not go far????????????. Probably towed from Goat Island back to Woolwich wharf..????
Take care my brothers for now. You are all champions!
Thank you and stay safe!



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"Advised by many not to rebuild YSE8! Why? New engine doesn't fit." started by Serb1980