Engine Smoking, Cleaning injectors on Yanmar YSB-12

[Royal Flush]

I've noticed oil in the water at times during startup. Recently on my last trip, I've noticed the engine is smoking much more so than ever. The oil level is good. I just recently made new connections on the water muffler to stop a leak which was sending water along the floor to the galley. My peers here are suggesting a possible injector issue. What do you all think?

-Mac

 

[RichH]

Diesel engines depend on the temperature of the combustion chamber as well as the 'compression' to burn the fuel oil efficiently. It takes some time for the combustion chamber to get to 'normal operating temperature' so what you may be seeing is 'normal' for your engine.
A more important question would be: is there any noticable 'oil slick or soot' on the water when you restart the engine ...... once it becomes fully 'warmed-up'.

When was the last time that you removed the injectors and had them checked at a local 'injector shop'? Such a shop can economically validate the condition of the injector, etc. I send mine out every ~750 engine hours (and every 40-50000 miles for my car injectors).

 

[Royal Flush]

I bought the boat a year ago and have no clue as to the condition of the injectors. What sort of place can evaluate the injectors? Especially on a while I wait basis?

-M

 

[RichH]

Just about every large town in the USA or Canada has an "injector repair shop". Just call your local 'auto mechanics supply' (NOT Pep Boys, or Autozone etc.) and ask for the closest reputable 'injector rebuilder shop'.
They are usually VERY busy so you will probably have to wait a few days for service.

 

[larryw]

RF- first things first. When you go to the doctor, he doesn't yank your appendix out to check it. Put a dose of Marvel Mystery Oil in your fuel and run it out. Don't baby the engine, warm it up and run it hard, 90% of WOT, under a load, for fifteen minutes, and for fifteen minutes every time you go out. You should start to notice a difference soon.

 

[Jalepeno]

My boat has a YSM-12 (basically the same as a YSB-12) with unknown thousands of hours and have not ever seen any abnormal condition of the exhaust, except steam when it over-heated once (but that is another long story). She had a healthy pass from a local Yanmar service shop as part of the prepurchase agreement a couple of years ago. I have never observed soot or oil in the exhaust. Does yours start right away (within a revolution or two) or do you have to run the starter motor for a long time? Try your hand crank to slowly turn her over and get a feel of the compression. My compression is good (about 22:1) and it takes a lot of effort to slowly turn the crank over the compression point. Be careful she doesn't start when you don't want her to. The oil in the exhaust must be unburnt diesel (fuel oil) that may be from the initial starting. Like larryw said diesels like to work, don't run them at idle or slow speed for a long time. Hang a bucket with a line over your transom to capture a sample of your exhaust cooling water and examine it both at startup and after you have run it at 2500 to 2800 RPM for five minutes in gear, securely tied to the dock (but watch your wake).

 

[Bud22569]

I have an old YSM-12 that I have rebuilt. There is only one injector on your engine. A new injector costs about $40 and is very simple to install.

 

[remo7e]

Can anyone recommend good web sites to get YSM 12 parts? I'm in Japan and they are VERY expensive here. (As is anything to do with recreation)

 

[tommays]

The problem with Japan is that it will have to pass through customs anyway and will get a tarrif

 

[okawbow]

That engine was used on other applications, such as small tractors, and water pumps. You should be able to get parts locally at an agriculture store. I agree that replacing the injector is about the same cost as getting it rebuilt. It only takes a few minutes, and is less trouble than a rebuild.

 

[Hermit Scott]

I have an old YSM-12 that I have rebuilt. There is only one injector on your engine. A new injector costs about $40 and is very simple to install.

Where did you find a YSM12 injector for $40? List price is probably a couple of humdred!

When I had my boat overpropped I would notice a significant amount of oil slick in the exaust when I would throttle it up. Since I propped down, I haven't noticed any even while throttled all the way up.
I see some smoke in my exaust now, after about 40 hours on it after the rebuild.
I can't really hand crank my engine with out the compression release on. I remember when I first rebuilt it, I came on here and asked how anyone could hand crank a diesel. I am in pretty good shape, but that it was impossible. Then I was told that was what the compression release was for. As well as killing it if it runs away.

 

[Bud22569]

Where did you find a YSM12 injector for $40? List price is probably a couple of humdred!
quote]

I bought the complete fuel injector assembly from Mastry in Florida for $91.82 (part # 704571-53100). I also bought the injector cartridge (124770-53000) as a spare, which should usually be all you need to rebuild the injector, for $40.23 from Mastry. Prices are similiar (slightly higher) at Torreesen in Michigan.

 

[woodster]

i am glad to read your post about Mastry Bud ...i am doing a ring job on my 2qm15 and have been priceing out the parts on torresen to night and was woundering if i was giong to see a big price dif ...but after what you have stated it prolly wont be worth the leg worth to see...also torresen cant sell to me in ga so now i dont feel like a hostage to priceing ...thanks for the positive comment

regaurds
woody

 

[Capn Ellis]

Let 'er rip!

Don't baby the engine, warm it up and run it hard, 90% of WOT, under a load, for fifteen minutes, and for fifteen minutes every time you go out. You should start to notice a difference soon.

In my auto diesel mechanic days, we called this a "Stuttgart tuneup." Bring 'er to op temp a then run the snot out of a diesel on a regular basis. Send a full load of fuel through those injectors. Blow the carbon out of the manifolds and exhaust. Blast those valves and seats. She'll purr like a kitten for you.

 

[Royal Flush]

She was smokin 'cause we wern't using her enough RF Works great now.. Thanks everyone