YSB8 Stuck Rings/Rebuild Advice

[Dan Roeder]

I just registered for this board, though I’ve been reading it for some time now. I thought I’d start with a modest post on the elementary topic of diesel engine re-building. I’m looking at a 1977 Cape Dory 27 with a non-functioning yanmar (not sure if it is YSE or YSB 8). I did see it run about a year ago (usual black smoke, seemed like low power). I’m told now that there is little/no compression due to the rings being stuck and it will not start.

1.Does anyone have any tricks for un-sticking rings short of engine removal/rebuild? I’ve heard/read the following:

•WD 40 spayed into cylinder (I assume by removing injector) or air intake. Presumably the engine can run on it and it may break help free the rings.

•Put oil in cylinder (remove injector, put in oil, replace) then use ether to help start, theory being oil will help make seal/compression, start engine, and rings may re-seat

Let me know what tricks you have, and what you think of the prudence of these suggestions.

2.I would like to hear from anyone who has actually rebuilt a yanmar ys series engine themselves.

•Please give your opinions of how hard a job it is. I’ve done a lot auto mechanics in my youth (rebuilt carbs, replaced heads, removed/replaced engines and transmissions,) and am not afraid to try it.

•What constitutes a rebuild? Piston, sleeve, valves, guides, seals, bearings-What else?

•What specialty tools are needed?

•Also include estimated costs/time.

Thanks for sharing your opinions/experiences. I'm looking forward to being a CD owner!

[Oswego John]

Dan,

Are you certain that the rings are stuck. More often you might find a hung up valve or two. If the engine cranks over but you have no compression, chances are that the rings aren't hung up

Get yourself a couple of quarts of Marvel Mystery Oil. (Pure magic in a can.)

If MMO does the trick, I wont have to answer all the other questions.

Good luck,

O J

[Dan Roeder]

I've heard of Marvels Mystery Oil. Are you suggesting putting it in the crankcase, or directly into cylinder via the injector? Also, can the head be removed with engine in-situo and have valves reseated?

[John D.]

. . . from my 1978 CD27. It was running as of haulout last Fall, but the exhaust manifold was disassembled to remove it. It needs work, but runs. Make an offer.

[Oswego John]

Hi Dan

Marvel Mystery Oil is a very high quality oil. It can be mixed with fuel, added to the crankcase oil or poured directly on any exposed engine parts. It works equally well on gas and diesel engines. Read the back of the can.

The head can be removed in place if necessary, which will facillitate access to interior engine parts. However, I suggest that you inject the oil into the combustion chamber first and see if the compression improves. Give it a fair chance to work. I'm betting on a stuck valve.

I'm still curious to know if the engine will crank.

O J

[Oswego John]

Holy Moly,

What's going on here? In the last few minutes, I have received four PMs.

It looks like I won the bet. Dan just informed me that the diesel does, in fact, turn over. That erases mucho problems for him. Now, to get some compression in that block.

I also received other PMs regarding MMO. One was from a member of the board whom we are all familiar with but who will remain nameless for the time being.

He berated me for leaking out the news about the benefits of MMO. He believes that a larger demand for it will drive the cost up. He gave me the good news and the bad news concerning adding it to his crankcase and fuel for his big engine RV.

The good news is that the use of MMO has increased his fuel mileage by 50%. (from 6 MPG to 9 MPG at $3.00 a pop.) ROTFL

The bad news is that for a while, he had to keep changing his fuel filter as the MMO kept scouring the scuzz off the walls of his fuel tank.

It will do that as well as break down carbon deposits in the combustion chambers and valves. Some call it a tool box in a can. It's not a new product. I've used it on my 1934 Ford V8 and on a L- head 36 Plymouth.

Keep those cards and letters comin' (Dean Martin)

O J

[bottomscraper]

Is it true that it now comes in plastic bottles? Is nothing sacred?

[img]http://www.turtlewax.com/products/img/p ... el1gal.jpg[/img]

[Oswego John]

It comes in plastic bottles now? Say it ain't so, Joe.

Heavens ta Moygatroyd. What'll be next? Liquid Ivory Flakes? Free air for $.50 at the gas station where they won't even ask if you want them to check your oil? 100% virgin vinyl leather jackets?

Thufferwing Thuckatash, I've had it.
I'm outta here.

Dot dot dot dah dot dot, - doh

"That's all folks"

Daffy & Porky

[Joe Mac Phee]

Dan,

I rebuilt the YSB-12 in my CD-30 ketch a couple of years ago. I brought it home and worked over the winter. The biggest problem was finding the needed parts. Mack Boring was very helpful including finding parts in dusty bins back in Japan. A few parts were made from unobtanium and so we improvised.

I was able to borrow the special tools needed. A cylinder micrometer showed that the cylinder sleeve and piston could be reused. I replaced the rings and needed a ring expander and ring compressor. The head was pretty sad and I sent that out to a machine shop to overhaul the head including cutting a replacement seat for the exhaust valve. I removed the side cover form the block and used a dremel tool to completely clean out any deposits in the cooling system. The only other tools that come to mind are torque wrench for the head bolts and connecting rod bolts, feeler gauges for the valve adjustment and plastigauge for the bearing clearances.

BY FAR, the most valuable tools were the service manual and the parts manual. I was not able to find a YSB service manual and had to use a YSM manual which is close enough except for the injection pump area.

The engine itself is stone age simple. I said in another post that it was a reliable as an anvil and as complicated as an anvil (it also about as heavy as an anvil).

I do not think that you can wear out one of these engines. Most are murdered.

Good luck in your quest. I will answer any specific questions to the extent that those memory synapses have not gone out of warranty.

Joe Mac Phee

[Oswego John]

Hi Joe,

It does my heart good to read about someone who rebuilt his engine, as you did. At first, the project might seem awesome, intimidating and beyond a person's ability. I'd feel the same way if I had to bake a cake from scratch, sew a new dodger or make seat cushions.

In reality, once you open it up and see first hand what's entailed in the rebuild, it's pretty simple and straight foreward. God bless service manuals and your friend down at Jake's auto repair for guidance over the rough spots. The next time you get the urge to upgrade the "anvil", it'll be a piece of cake. The mystery is gone.

What I wanted to mention to others who might be doing major engine repairs to their boat now or in the future, most large chains of auto parts supplies will lend specialty tools to the DIYer after you put down a returnable deposit. There's no sense buying a specialty tool that you'll only use once in twenty years.

Congratulations on saving yourself mega $$$ as well as knowing that the job was done right.

Good luck, O J

PS: Was going to ask where you found rare Unobtanium. I've been searching for it since Hector was a pup.