Smokey Yanmar

[Acadia]

Hello,
It had been about 45 days since I last ran my Yanmar 44hp (4JHE I think) and it didn’t run quite the same as I last remembered. I will try to explain as best I can. Well, first off there is lots more blue smoke than there used to be. Before, you could just see a hint of it coming out of the exhaust. But now there is lots more. We don’t disappear in a hue of blue smoke but I would say at least 2, maybe 3 times more than usual.

The other difference is that the RPM is a little iratic. It will run normal but with infrequent and sudden small surges in RPM. Another noticeable thing is when I try to increase RPM passed 2000, say to 2400. It takes lots of time to respond, whereas before, it would smoothly follow the application of the throttle. The RPM thing really sounds like it would be an injector/fuel problem but I find it strange that it came at the same time that the engine would burn more oil.

During the those 45 days, I’ve done lots of re-wiring. The only wiring that would have affected the engine would have been changing the regulator to the one that came with the link 2000R

Although I am mechanically inclined, I am new to marine diesels... well all diesels for that matter.

Looking forward to your thoughts.........

Thanks

[Alan Wheeler]

So can you confirm a couple of questions for us. A simple yes/no for each is fine, but the more details you can give the better.

It has suddenly started using oil???

Nothing has been done to the engine at all since last time it was run??

The 2000 to 2400 RPM mentioned, is that in gear or out of gear??

Will the engine rev to it's rated RPM out of gear??

Did the engine ever rev to it's rated RPM in gear in the past??

Will it get close to Rated RPM in gear now??

The engine ran quite OK last time with no signs of any issues and was shut down as normal??

[GordMay]

Smoke Signals
Telltale Signs of How Well Your Diesel Engine is Performing
Goto: Diesel Smoke

BLACK SMOKE - Restricted air flow (dirty/obstructed air filter; plugged exhaust; restrictions in exhaust system; defective turbo/supercharger); Overload; Improper injection (poor atomization, injector dribble, late injection)

BLUE SMOKE - Worn or stuck piston rings; worn valve guides and stems; high crankcase pressure; worn / supercharger oil seals.

WHITE SMOKE - Misfiring cylinders; water in fuel; air in fuel; water in cylinders (blown head gasket, cracked head or liner); lack of compression.

[Acadia]

Gord May thanks for the link.

Wheeler;

I’ll try to answer your questions as best I can.

It has suddenly started using oil? – I haven’t noticed any change on the dip stick because I was only out for a day, I just saw more blue smoke and attributed that to burning more oil than usual.

Will the engine rev to it’s rated RPM out of gear?-- I don’t know I have never tried it and I don’t even know what the rated rpm is for the engine. I will look that up in my books. Is it safe to bring the engine to max throttle and see where the RPM will end up? Generally I don’t like doing that on any engine but I do not have the most experience with diesels.

The engine ran quite OK last time with no signs of any issues and was shut down as normal??
Again I am very new to marine diesels and I may not have all the proper techniques yet for good operation of the engine. When I start up I always like to have a 3 to 5 minute warm up period and likewise for shutdown (idle).

I will try and do more searches on the forum and try to educate myself a little more on these topics, in the mean time any pointers appreciated.

[Alan Wheeler]

At the top of this topic Forum, you will see a "studyhall". Have a read through the engine warm up procedure. But in short, never allow a Diesel to warm up with no load, and never allow it to idle for a time before shut down.
Chances are, you have no problem. You need to work the engine hard. Yes you can rev a Diesel to it's max RPM. It is a Governed engine and will not over Rev.
The blue smoke is likely unburnt fuel oil and engine oil sitting in the cyclinder, around the Valves and in the manifold. This accumulates for all the above idle reasons.
Get the thing into gear and get the engine working and open the throttle up hard every now and then. Diesel's like a good hiding.

[Chief Engineer]

Smokey Yanmar....sounds like a girl I used to know....Just kiddin...therre are a lot a good guys on this board

[Therapy]

Originally Posted by Alan Wheeler

never allow a Diesel to warm up with no load,

Never heard that.

Please expound.

[never monday]

Originally Posted by Therapy

Never heard that.

Please expound.

http://www.cruisersforum.com/forums/...ines-9325.html

[Inthewind]

Being that your new to diesel engines, you are not familar with Yanmar engines or any diesel for that matter. They all smoke more than normal when sitting for lengths of time, heck they smoke anytime you crank them up cold. Fuel drips down into the cylinder causing what seems to be excessive smoke from unburnt fuel. Don't be alarmed, it perfectly normal for these engines. Get out and run that thing and I am sure you will be just fine, worry about something else because I don't believe you should be worrying about your Yanmar. I have worked around Yanmars for many years and I have yet to see any catastrofic failures or problems that require a tear down. They are very dependable for many thousands of hours with proper maintanance.(oil changes,raw water pump impeller,belt,filters, that's it) good luck.

[Chief Engineer]

I see/hear this concern many times at the beginning of a season.

Many of us sailors run their engines like this: Load vessel, Start Engine, Leave Dock, Raise Sails as soon as possible, Sail all day, Return to Marina or get to destination, Drop Sails start engine and dock or anchor.

The engine never gets a chance to run at operating temperature for any sustained time......

Fair Winds and RUN THAT THANG!!!!!!

Originally Posted by Inthewind

Being that your new to diesel engines, you are not familar with Yanmar engines or any diesel for that matter. They all smoke more than normal when sitting for lengths of time, heck they smoke anytime you crank them up cold. Fuel drips down into the cylinder causing what seems to be excessive smoke from unburnt fuel. Don't be alarmed, it perfectly normal for these engines. Get out and run that thing and I am sure you will be just fine, worry about something else because I don't believe you should be worrying about your Yanmar. I have worked around Yanmars for many years and I have yet to see any catastrofic failures or problems that require a tear down. They are very dependable for many thousands of hours with proper maintanance.(oil changes,raw water pump impeller,belt,filters, that's it) good luck.

[never monday]

I've come to term this mode of operating a diesel
"killing it with kindness" or "lazy engine syndrome"

[Elie]

In my experience, this kind of sudden problem occurs when your filter are partially blocked and you have taken bad fuel(or your fuel has become infected). The first thing I would do is to replace the filter and have a deep look at what's in the fuel filter bowl. If its greasy and black, dirty, that's it!. Dirty fuel will make a engine smoke a lot, all colors!. Unless you have something caught in your prop, ant this smocking occurs only when in drive.

[Richkd]

Never_Monday has adequately demonstrated for me recently the results of "killing it with kindness" I should take pics of the condition and cure, before and after.

Thanks again Pat.

[Tellie]

Originally Posted by Alan Wheeler

At the top of this topic Forum, you will see a "studyhall". Have a read through the engine warm up procedure. But in short, never allow a Diesel to warm up with no load, and never allow it to idle for a time before shut down.
Chances are, you have no problem. You need to work the engine hard. Yes you can rev a Diesel to it's max RPM. It is a Governed engine and will not over Rev.
The blue smoke is likely unburnt fuel oil and engine oil sitting in the cyclinder, around the Valves and in the manifold. This accumulates for all the above idle reasons.
Get the thing into gear and get the engine working and open the throttle up hard every now and then. Diesel's like a good hiding.

Study Hall says.......
7: Now you can safely bring your engine back to idle and allow temps to return too normal. It is good to run the engine for a few minutes at idle to ensure all internal area’s are cooled correctly and evenly before shut down

Youse guys are confusin the heck outta me.

[never monday]

3-5 min. not 10-15 min

clearer?