Yanmar L70 - Heavy (lots) smoke

[i012783]

Hi - I picked up a MEP-831A generator at a military auction. It arrived drained of fluids so I PM'd it and added new fuel/oil. It started up but had very heavy smoke coming out the exhaust. Here is a video of it when I started:

Just looking for ideas of troubleshooting? I'm mechanically inclined but never torn one of these down. Pull head and see damage? Any other ideas of what might cause this level of smoke?

Thanks!

 

[winston1]

Two things . 1. sounds like it is over speeding or am I just hearing things? 2. Looks like oil burning off of something rather than exhaust smoke. I am unsure, can you confirm?

 

[ponytug]

It does sound like it is a bit erratic on the combustion, but the smoke looks like oil to me. I think that this is a 3600rpm generator, right?

 

[ruffdog]

You say it was "drained of fluids", but maybe it had tipped over and filled the exhaust with oil before you bought it?

 

[Tinhack]

All I saw was a video of someone overly excited. I couldn't tell what I was supposed to be looking at. Good image of the battery for a second.

 

[bmaverick]

Hi - I picked up a MEP-831A generator at a military auction. It arrived drained of fluids so I PM'd it and added new fuel/oil. It started up but had very heavy smoke coming out the exhaust. Here is a video of it when I started:

Just looking for ideas of troubleshooting? I'm mechanically inclined but never torn one of these down. Pull head and see damage? Any other ideas of what might cause this level of smoke?

Thanks!

Do ask in this section, they are very well versed in the Yanmar L-series engines,

Forum for air cooled diesel engines and clones

From what I’ve seen it’s the cheap Chinese clone parts that are inferior. The camshaft material is inferior with improper or no heat treatment. An oem Yanmar cam & bearing may be interchangeable which would solve that problem. The quality of clone parts varies from terrible to good/great. Are...

www.tractorbynet.com

 

[90cummins]

I agree it sounds like it’s over speeding. I would adjust the governor linkage to reduce the speed as my 1st step in diagnosing.

90cummins

 

[FullMetalBucket]

Was it stored for a while? Maybe the PO put some oil in the cylinder(s)?

 

[careyo63]

That is true Esp. Since it was stored for ?. The PO may have did it to keep the rings free. It's not lock down so that a big Plus!!

 

[ponytug]

That is true Esp. Since it was stored for ?. The PO may have did it to keep the rings free. It's not lock down so that a big Plus!!

If it is ex-DOD, the protocol is to drain everything, so that is unlikely. I think a perhaps bigger challenge is that almost anything could have been done or happened before the unit was scrapped. Sometimes the "non-repairable" cause is something easy for a civilian, sometimes less so, but I try to remember that even on the DOD side not everyone who touched the unit was an expert, and some units were used for training, e.g. stripping the generator all the way down to nuts and bolts and reassembling it.

@i012783 if you don't already have all of the technical manuals, I would suggest down loading them, especially the TM 9-6115-639-13&P manual, e.g.

Manuals for the MEP-831A

Here are the manuals needed to work on the MEP-831A. Please ignore the schematics in the TM 9-6115-639-13&P. The more readable copy is the last uploaded file, Courtesy of Member Kurt Klopp.

www.steelsoldiers.com

I think that the good news is that the Yanmar engine is rock solid, and easy to work on.

All the best,

Peter