MEP-831A - Huge amount of exhaust smoke

[2Pbfeet]

Video after new valve seals:

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That would qualify as a good smokescreen generator in my book. That seems like a lot of unburnt fuel, and/or low compression.

Any chance that the decompression lever could be slightly interfering with the valve? (The lack of wear on the rocker arm suggests that it is ok, but it is an easy check. There should be some play in the lever before it contacts the rocker arm.) I believe that using the decompression lever is not a great way to stop this engine.

If it were me, I would start by getting the fuel leak at the pump sorted out. The Yanmar engines are (rightfully) rather intolerant of anything that alters the pressure in the injection line- air leak into the suction side of the pump, and on the pressure side, fuel loss, a damaged flare, dirt/ debris on a flare fitting , plus of course a bad injector. In my experience even a tiny weep on an intake line is more than enough to overfuel the engine and cause issues.

I would double check that the pin of the pump is in the yoke of the governor.

FWIW: I keep a stock of new/known good injectors and pumps for these engines on hand. I find that it speeds up my troubleshooting.

All the best,

2Pbfeet

 

[zapp]

Thanks, I had a new (Chinese) pump I had gotten just in case and gave it a try. Once it fired up, it cleared the smoke for first minute or two then I started to get a little bit but nowhere what it was before. It definitely improved things. I'm wondering if there might be some left over oil in the muffler and as it was heating up and generating smoke. Also, it cleared up the governor actuator problem , and I could shut down the engine with the switch. I was able to check the courtesy outlet and lugs and getting 240v and 120v on L1/L2/N so that's good. It's raining here today so my next step is to run it at full load for an hour or two and see if the remaining smoke clears up.. Thanks for the encouragement and insights. Changing valve seals was really pretty straight forward once got in to it.. As always RTFM is step #1..

Here is a link with new IP:

- YouTube

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[2Pbfeet]

Thanks, I had a new (Chinese) pump I had gotten just in case and gave it a try. Once it fired up, it cleared the smoke for first minute or two then I started to get a little bit but nowhere what it was before. It definitely improved things. I'm wondering if there might be some left over oil in the muffler and as it was heating up and generating smoke. Also, it cleared up the governor actuator problem , and I could shut down the engine with the switch. I was able to check the courtesy outlet and lugs and getting 240v and 120v on L1/L2/N so that's good. It's raining here today so my next step is to run it at full load for an hour or two and see if the remaining smoke clears up.. Thanks for the encouragement and insights. Changing valve seals was really pretty straight forward once got in to it.. As always RTFM is step #1..

Here is a link with new IP:

- YouTube

Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube.

youtube.com

That looks and sounds healthy from this armchair.

Congratulations!

All the best,

2Pbfeet

 

[CallMeColt]

I'm late to the game, but you never checked the injection pump or governor adjustment before ripping into the head? I can tell from all of these I worked on that 100%, that was a WAY overfueled engine. The white smoke was unburn fuel. Have seen it many times on these. Caused it a few times myself. Here is a video of one with a pump that was sending way to much fuel.

 

[zapp]

Yes, I pulled the IP and was able to compress the spring and move the arm without any binding and assumed it was fine as one of the first steps. Pulling the head off and springs wasn't a big deal and a good learning exercise. Biggest pain was getting the two bolts on the back of muffler going.

 

[CallMeColt]

Yes, I pulled the IP and was able to compress the spring and move the arm without any binding and assumed it was fine as one of the first steps. Pulling the head off and springs wasn't a big deal and a good learning exercise. Biggest pain was getting the two bolts on the back of muffler going.

Sorry, I must have missed that when reading. Sure looked like a pump issue. I'd replace the China injection pump as soon as you can. They are TERRIBLE. You may get 50 or so hours before it grenades. They don't properly harden the internals. Genuine Yanmar ones seldom go bad.... odd to see one that has that physically wasn't damaged by someone who didn't do something to it. I might have one somewhere as I worked on a bunch of these engines at one point.

 

[CallMeColt]

The smoke is more than likely what you suspect... oil & fuel built up in the muffler. Along with anything else over it's time that may be burning off.

I would run it at 50% load for one hour & then 100% for 6 hours to fully test it. Make sure it ramps up & down as it should first & adjust the controller as needed. There is a nice upgraded controller as well.