Onan DJC Wet Stacking

[@billmoran3812]

Wet stacking is common on diesel generators and other diesel engines that idle or run unloaded for long periods of time. It is a result of low cylinder pressures that allow lubricant oil to bypass the rings because the rings exert less pressure against the cylinder walls. This is especially a problem on air cooled diesels as they have difficulty getting up to operating temperature without sufficient load. Diesels like to have between 70% and 100% load. That’s where they are most efficient. Long idling and low loads can eventually cause stuck rings and glazed cylinder walls. I used to work on locomotives that spent many hours at idle. As part of normal maintenance several times a year, we cleaned out the soot traps in the exhaust manifold. Usually get a 5 gallon bucket full of heavy oily soot, caused by wet stacking. Ocassionally when running a locomotive hard, all that junk would catch fire in the manifold and we’d have flames out the stack!

[@JoshKilen]

nice job, to help prevent wetstacking run between 50-75% of it rated load.

[@moondogdieselworks3883]

Awesome comment, that is exactly what happened.

[@jeffanthony5434]

What a collection of nice machines!

[@KraeseRepairs]

My DJA had that issue when I first got it, The previous owner would run it for a few minutes, then shut it down and it became hard to start. He never let it get up to operating temperature and under a load to burn all of that off. I cleaned it all out and no I don't have any issues with starting and when I run it occasional I always let it run at least an hour.

[@lordnetsplits3192]

This wet stacking happens to 2 stroke gasoline engine exhausts as well. I think it happens because diesel which is oily and gasoline 2 strokes use oil in the fuel.

[@Jbyrd75901]

All that green in his garage...

[@RingingResonance]

Yeah, now we know who has been buying up all the Onan touch up paint! I went to home depot and had them match up the color on the better looking panel for mine and got an oil based paint. Disclaimer: I don't know much of anything about paint... Anyways, I removed and cleaned all the panels and shrouds, lightly sanded them, primered and then I brushed on satin finish following up by reassembling and dabbing it all around to give it a sort of industrial textured look with the simi-gloss. Turned out to look pretty good IMO. No idea how well oil based paint will hold up in this application on my 4.0BFA.

[@jjjj-uf4bw]

The complete story/thread posted on the SmokStak forum is here -> www.smokstak.com/forum/threads/wet-stacking-when-running-my-djc-unloaded-the-ugly-story.213538/

[@thegatestopper]

so i have a able 9kva diesel and i have wet stacking and thanks for the vid as i have never heard of it so what would it do to the engine

[@oscarsantiago9099]

Saludos donde consigo el regulador de voltaje original de una máquina marina MDJC??

[@wildman4642]

Definetly wet stacking... I have experienced this with an RDJF

[@jjjj-uf4bw]

If you would like to share your experience with wet stacking with your Onan, please join us on the Onan Smokstak forum. The thread for this subject is here -> www.smokstak.com/forum/threads/wet-stacking-when-running-my-djc-unloaded-the-ugly-story.213538/ To post comments you will have to register which is easy/pain free. Your input on the subject or anything Onan related will be greatly appreciated.

[@Radmard1]

ODJC-CE/8523AA This one is Diesel, I am trying to rewire as 3 phase 380 volts I could not find wiring diagram. and I have 12.5 JC-18R/25786AD This unit it has a selector switch that you can select different voltages, again I need to rewire for 3 phase 380 volts please help me to rewire them. thank you in advance

[@Radmard1]

Hi johni I believe there is some thing wrong with your fuel injection injection system that it is to reach on idle. By the way I have few Onan generators, I attach name plates for your information,

[@1_LONEWOLF]

How do I get to the forum for this?

[@coopershistorygarage2804]

Go to smokstak.com, go under the sub heading “Vintage Electrical Equipment,” Onan Generators and you’re there. No dumb questions there!

[@jjjj-uf4bw]

The actual thread on the subject is here -> www.smokstak.com/forum/threads/wet-stacking-when-running-my-djc-unloaded-the-ugly-story.213538/ We are already have 3 pages for this thread and growing.

[@SKSweet]

Thanks

[@rodneyswearingen1020]

Its just condensation like a gas engine makes due to no load.

[@matthewcarey2871]

That's wet stacking, the combustion cycle doesn't create enough heat at idle or unloaded to completely burn all the fuel sending the "heavier" harder to burn parts of the fuel out of the exhaust.

[@1vester1]

wet stack not good something not right low compression fuel not burning clean.