Yanmar Injector Removal Picture

[endoftheroad]

I have the black soot in the water from exhaust issue that suggests my injector needs is in need of attention.
I was unable to remove injector at anchor so I removed the head and have it on land.
The motor has great compression (starts immediately) and doesn't burn any oil.

I haven't removed the injector yet as I'd like to share a couple pics for observations from my fellow cruisers.

note that the reddish/orange in the picture is from reflection and not hardly rust, it only shows in pictures and looks clean in person, the head came off just fine for a 30+ year old motor (Yanmar YSB8).

I am not sure about the oddball ring on the piston in the picture as I didn't notice it till just now viewing photo. I am hoping it is just a camera angle thing.
Remember, the thing starts up fine and runs great till under load (tides/currents).

Opinions?

[never monday]

I see some corrosion from a salt water environment. I also see the fuel flame front on the piston. Nothing unusual...

while the head is off lap the valves in and get new valve guide seals.

[foggysail]

No mechanic here although I will share what I once watched. It also was on a Yanmah.

The instruction was to remove/loosen those things related to the injector. DO NOT REMOVE what I will call a keeper. On the engine I saw, there was something protecting the injector from flying out. Very important not to remove it, could cause great injury if removed.

Next, turn the engine over. NOt sure if this was by hand and that engine had a hand crank. Been too long to provide details. The compression would pop out the injector.

More important things----never put any part of you body in line with the injector's nozzle. The pressure is very high, you will need a trip to a hospital if fuel oil gets injected into your skin.

Here again, a little knowledge can be dangerous so be careful and I ain't no mechanic so keep anything in this post in that " I ain't........." light.

One final comment from my know nothing experience. Black soot may or may not be caused by injectors. I once had mucho black soot poring out the exhaust. Problem was a DIRTY INPUT AIR FILTER!!! Hope you pulled that head for the right reason and good luck.

Foggy

EDIT: Your pictures appear to show a bad head gasket

[endoftheroad]

Silly me,

I just got out to the boat and that camera illusion thing is just the head gasket being offset making the ring look narrow on one side.

That was very GREENHORN of me.



Thanks

[endoftheroad]

Originally Posted by never monday

I see some corrosion from a salt water environment. I also see the fuel flame front on the piston. Nothing unusual...

while the head is off lap the valves in and get new valve guide seals.

I can't find where my model (Ysb8) has "valve guide seals" on any parts diagram.

Is it common to wash the head and its contents in diesel fuel?
If so, should I lubricate with oil before re-install?

[jannpage]

Hi. If it were my head, I would rush to the nearest Automotive machine shop. Most of them do trucks and farm tractor heads that are diesel and see waht they say. I think you problem is not the injector. But let the machinist tell you what to do. Of dcourse, if anywhere near a GOOD Yanmar dealer, let him look at or send you to where Yanmars are fixed. It may cost you a few bucks, but don't hwlf fix it. YOur live may very well depend on this engine.

cheers Page

[endoftheroad]

Actually in person the head looks great.
A great yanmar dealer saw it today and said it's in very good condition.

I have one of those plunger type lapping tools.
Should I sand or use a wire wheeled grinder to clean the top of the valve for the plunger to stick?

Can I clean the head in brake cleaner?
And then use some motor oil to re-lubricate?

[endoftheroad]

Yanmar doesn't require sealant on the head gasket.

But maybe they base this on a perfectly machined head.
This is not the case with my head.

I would like to use some sealant.

Any suggestions?

[roverhi]

Check with Yanmar before you use any kind of sealant on a head gasket. The only sealant I've heard of for a head gasket is a slight smearing of oil and even that is not common. The new style head gaskets may not need, in fact it may not be reccomended, to be retorqued after a short run time. Once again, check with the manufacturer.

Since you've gone to all the trouble to remove the head, might want to get a valve job done. Wouldn't hurt anything and may save on future repairs.

[perchance]

Originally Posted by endoftheroad

I can't find where my model (Ysb8) has "valve guide seals" on any parts diagram.

Is it common to wash the head and its contents in diesel fuel?
If so, should I lubricate with oil before re-install?

The valve seals are under the springs and may be difficult to see but they are there or should be. Cast iron engine blocks and heads are/were boiled out with caustic soda and this will remove carbon,paint and just about every thing organic. Buffing the valve faces with a wire wheel will clean them. The lapping tool used with grinding compound is designed to do a final seating of the valve to remove any remaining imperfections between the valve and seat ensuring a good seal. Depending on the number of hours on the engine it is always a good idea to have the stem and guide clearance checked since you have the head off anyway. Any good automotive machine shop will do this and other checks. Have your injectors pop tested at the same time by a competent diesel shop for peace of mind and you will have many more hours of trouble free operation.

[jannpage]

Hi. I still would carry the head to a good machins shop. I really am a good engine mechanic and I would never trust my eye to tell me if a head is true enough to put back on. They probably would not even charge you to check if for "true" and no eye can see 1 or 2 thousands of an inch warp. It is your life - but cheap fixes are always doing it right. And get a torque wrench to put it together with. And a decent sevice manual.


Cheers

Page

[endoftheroad]

Thanks for the help!

I am on it.


Also,
does anyone use any pipe joint compound/sealant on the mixer elbows and their nipples/couplings?


Thanks

[roverhi]

Highly reccomended to use liquid teflon gas type sealant. Don't know how much good it will do as getting the mixing elbow off the exhaust pipe is a job for BIG pipe wrenches and cheater bars. On mine, needed a humongous vice firmly bolted to a wall and the ground and a pipe wrench with a 3' cheater bar with two of us hanging on it to get the elbow loose.

[Badsanta]

You did not state if this smoke just started or what. After you put things back together I would check your prop to see if you have a rope around it or it's just real dirty. Simple things first. Best of luck

[endoftheroad]

Originally Posted by Badsanta

You did not state if this smoke just started or what. After you put things back together I would check your prop to see if you have a rope around it or it's just real dirty. Simple things first. Best of luck

My reason for this thread wasn't to help me diagnos the problem, the problem I have already identified.
It's the re-install that I am looking for help.

I have searched like crazy to find the best sealant to use for my mixing elbow and fittings to the Head.

I can not get help with the question, I am not sure that anyone has a standard use sealant and most just "wing it".

The previous owner used some sort of pipe thread, I have the mixing elbow and nipple taped up sitting at my shop filled with fuel and there is seepage from some of the tight connections expecially at the first joint after the exhaust elbow where the most heat would be.

This leads me to not believe that sealant isn't necessary as some suggest, and it also suggests that plumber's pipe thread can't take the heat.

High Temp Copper HTV #81878 sounds good but it is a gasket maker and not a thread sealant.

Does anyone really know of a standard sealant?

Believe me, I have worked hard to try and find the answer, I can't come up with one.