Mep 831a black smoke won't rev up and shooting flames out the exhaust

[Captainscall]

I knew it was valves! It very well could have been you adjust them, and when you tightened, they moved. VERY easy to do that on these. Trust me, I know... makes you realize how stubborn these little engines are to just run even when they shouldn't.

Yes, there are thermal switches for the fans. You want the box warm to help with wet stacking so it waits. Each fan is different as well.

The thing that drives me nuts is that valves was the first thing I checked. I must have used the wrong spec because when I adjusted the valves it made no difference so I assumed that was not the issue and moved on. Or like you said they moved when I tightened them. Oh well, live and learn!! And double check your work!!

Thanks again for everything!!

By the way i did a load test on my 802a today. Everything worked perfectly but man it is a shaky machine!! Was not near as smooth as I would have expected!!

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[CallMeColt]

MEP 802 will go for a walk. I put mine on the sand. It still shakes the garage. After a day, they tend to "settle" in.

 

[Captainscall]

MEP 802 will go for a walk. I put mine on the sand. It still shakes the garage. After a day, they tend to "settle" in.

I noticed that when it was on my garage concrete floor. It would walk around by itself about a foot every minute. I built a dolly with 2x6 lumber and locking casters. It did not move today but since the skid was not on solid ground it shook the whole machine like crazy!!

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[2Pbfeet]

Congratulations on getting it sorted out and running!

For me, it certainly took some practice to get the hang of adjusting and setting the clearances on some engines. I find some designs to be more tolerant of uncoordinated moves by me. Once you have the Yanmar valves set, and broken in, I think that they tend to be quite stable.

I think that smaller diesels, especially one and two cylinder versions, can be handfuls and some are quite prone to vibration. Newer designs tend to have more vibration and noise control built into the engine, at the cost of making the engines more complicated.

All the best,

2Pbfeet