Need help with MEP-831A blowing black smoke on startup

[Navy GiJoe]

A friend of mine decided to get a generator just like mine. We looked it over and it appears complete. Some of the insulation has been chewed on, but all the wires and hoses were fine. We changed the filters and the oil, put some diesel in it and fired it up. It immediately started blowing jet black smoke. I looked at the fuel pump and noticed it had no shims. Could this be the reason for the smoke?

 

[BobbyT]

How long did you let it run? If you ran it for a while and it still was blowing black smoke, then you are getting too much fuel. Just thinking it could have been some of the old gunk left in the system causing incomplete combustion if you didn't let it run for a while to see if it cleared up.

 

[Navy GiJoe]

How long did you let it run? If you ran it for a while and it still was blowing black smoke, then you are getting too much fuel. Just thinking it could have been some of the old gunk left in the system causing incomplete combustion if you didn't let it run for a while to see if it cleared up.

BobbyT, I ran it various lengths of time, the longest was around 20 minutes because I was thinking the same thing as you. After that I started looking at the fuel pump and injector.

 

[Ray70]

Have you been running under a load, or just running with no load?
I have one that was doing something similar and the adjustment of the linkage on the speed controller was out of whack.
It would randomly chug black smoke and then be fine other times.
Running under a load and seeing if the speed control is working correctly might help identify if you have an adjustment or controller issue.
KKlop is the local authority on the 831, so he will probably be able to help.

 

[Navy GiJoe]

Have you been running under a load, or just running with no load?
I have one that was doing something similar and the adjustment of the linkage on the speed controller was out of whack.
It would randomly chug black smoke and then be fine other times.
Running under a load and seeing if the speed control is working correctly might help identify if you have an adjustment or controller issue.
KKlop is the local authority on the 831, so he will probably be able to help.

It starts blowing black as soon as it fires up. I have not tried putting a load on it yet.

 

[synelecpb]

Mine puffed black smoke at startup when I first got it, and even did it a little when under load after doing a bunch of maintenance - until I changed the air filter. The unit only had 75 hours, and the filter looked fine. Changed it out on the suggestion of folks on this site, and presto - no more chumming smoke even at full load.

 

[Navy GiJoe]

Mine puffed black smoke at startup when I first got it, and even did it a little when under load after doing a bunch of maintenance - until I changed the air filter. The unit only had 75 hours, and the filter looked fine. Changed it out on the suggestion of folks on this site, and presto - no more chumming smoke even at full load.

Thanks, I will try that.

 

[Bmxenbrett]

Black smoke is usualy to much fuel if it's not wet stacked.

If it only blows smoke right at start up you should have an injector that is stuck open a bit or needs to be adjusted.

 

[Navy GiJoe]

Thanks