Mep 831A load issues

Crosshead? As in large engine/compressor? Saw?...
Just curious.

I am glad that itis working well for you now!

All the best, 2PbFeet

Sorry no. We were sinking a 29 foot diameter shaft down 2140 feet and the crosshead was the device that hung between the cables and guided the buckets and man cage from surface to hole bottom. I had communication devices on the crosshead to monitor status and provide coms. It used the cable as an antenna and I also used wifi antenna to send a camera feed back to surface from the crosshead also so we did that with a battery swap daily. I was trying to find a picture but i have the wrong phone on me.

I still haven't done a legit load test so I'm hesitant to believe it's fixed. I've seen it do well for a minute before. Lol. The signs are promising though. Tomorrow I should be home and have everything in place to test for some hours. (Fingers crossed)

Ha. ..
I think i might cry!!
It's still pretty much the same once it warms up.
So the only thing that's not new including the piston and cylinder wall is the injection pump and the exhaust. Could something be in the exhaust clogging it? How would I check that?
I'm seriously at a loss. It's a fair bit better with the throttle locked on full and avoiding the actuator all together but still not 3kw. Heck not 2750 for long. When it first fires up cold it can hold 3k for a bit. When I got it to hold 3250 it was cold and I had the air filter out with the cover off the front. Maybe I'll try with no exhaust. For now it's going too sit for a while.

Anyone want an 831 with low hours? Ha ha.

I have another little gen that's not military but has a yamnar L100 and it has no problem holding rated load here which makes me think the elevation shouldn't be dropping me to 2500.
Honestly the only load it holds well without looking like it's working it's but off is 2kw. Funny. Makes me wonder about the writing on the gen.
See it says load 20.
Is that load 2.0k? I don't know. I have a new L70 I was thinking of using to convert a mini ex to diesel. Maybe I'll see how that runs the gen. Then the only thing not new would be the exhaust.

grywitt said:

Ha. ..
I think i might cry!!
It's still pretty much the same once it warms up.
So the only thing that's not new including the piston and cylinder wall is the injection pump and the exhaust. Could something be in the exhaust clogging it? How would I check that?
I'm seriously at a loss. It's a fair bit better with the throttle locked on full and avoiding the actuator all together but still not 3kw. Heck not 2750 for long. When it first fires up cold it can hold 3k for a bit. When I got it to hold 3250 it was cold and I had the air filter out with the cover off the front. Maybe I'll try with no exhaust. For now it's going too sit for a while.

Anyone want an 831 with low hours? Ha ha.

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Did you try feeding a little compressed air into the intake while running to see if it smooths out at load? You fixed the compression issue, so you're down to either fuel or air.

The only other thing I can think to try here is pull the injector, the hard line, and soft return. Turn the hard line around and reattach the injector open-air (return too). Prime and bump the starter, and observe that none of the jets are clogged and that you're getting a well-atomized spray.

vrzff said:

Did you try feeding a little compressed air into the intake while running to see if it smooths out at load? You fixed the compression issue, so you're down to either fuel or air.

The only other thing I can think to try here is pull the injector, the hard line, and soft return. Turn the hard line around and reattach the injector open-air (return too). Prime and bump the starter, and observe that none of the jets are clogged and that you're getting a well-atomized spray.

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I didn't try with the air compressor but with no air filter it improves but not fixed.
So I think it might be the exhaust. I just pulled the exhaust off and ran it. I had it at 3kw for quite a while with very minimal smoke but the neighbors 3 miles away were getting irritated. Ha ha. I did make the mistake of having a couple things different at the same time though. Yesterday I took the two aftermarket injectors I had and swapped the guts to see what happened and it didn't run well.

So today I took the side cover off again and removed the exhaust. It still didn't run well. So I dug out the original injector and put it in but left the return line attached to the old injector and tried it. It coughed a few times and smoothed out then I went and got the load bank. I put it at 3kw and walked away and made coffee. I had checked the spray pattern before and it looked good BTW.

I think this machine has been left wet in the past. A head bolt was very rusted. I wonder if a lot of water has sat in the exhaust. I need a good way to know if it's okay. Not a drop of fuel came out of the return line I had dangling down.

I guess I need to attach the return line correctly and see if it holds. I need to drive ten miles out in the desert to continue these tests. Oh Also I put in a brand new air today. I hesitate to think I've found the problem still as it has done this before when cold. It's so loud like this.

grywitt said:

I didn't try with the air compressor but with no air filter it improves but not fixed.
So I think it might be the exhaust. I just pulled the exhaust off and ran it. I had it at 3kw for quite a while with very minimal smoke but the neighbors 3 miles away were getting irritated. Ha ha. I did make the mistake of having a couple things different at the same time though. Yesterday I took the two aftermarket injectors I had and swapped the guts to see what happened and it didn't run well.

So today I took the side cover off again and removed the exhaust. It still didn't run well. So I dug out the original injector and put it in but left the return line attached to the old injector and tried it. It coughed a few times and smoothed out then I went and got the load bank. I put it at 3kw and walked away and made coffee. I had checked the spray pattern before and it looked good BTW.

I think this machine has been left wet in the past. A head bolt was very rusted. I wonder if a lot of water has sat in the exhaust. I need a good way to know if it's okay. Not a drop of fuel came out of the return line I had dangling down.

I guess I need to attach the return line correctly and see if it holds. I need to drive ten miles out in the desert to continue these tests. Oh Also I put in a brand new air today. I hesitate to think I've found the problem still as it has done this before when cold. It's so loud like this.

Click to expand...

It may have been pressure washed coming back from overseas.

As @vrzff points out, fuel and air are now the prime candidates, and as the injector was working well before, I would be inclined to suspect that the muffler is clogged or obstructed. I would give your engine a few hours to settle the rings in, before pushing it to the limit. From here, it seems pretty good. I would run it at whatever load it can handle for a few hours and then try raising it a bit and repeat. If it gets hot, it might start spraying glowing or flaming carbon, so I would do the test somewhere that spraying embers won't cause fire issues.

All the best,

2PbFeet

So I just ran it for another 15 minutes at 3kw then I took off the load and brought it up again and it held. This is all with the actuator BTW.
They I took off the load and tried to give it 3kw all at once. It didn't line that but 2kw then another 1kw a couple seconds later it held. With no exhaust on the head it seems to be a 3kw machine. Anyone seen this before? It is definitely not TQG without the exhaust lol.

Oh and I reattached the return line to the injector this run. So the fuel system is normal and complete. I don't know. I'm scared to buy one off the used exhausts on ebay. Hmmm. Any ideas on my next move?

The exhaust looks fine

You mean run it a few hours with no exhaust?

2Pbfeet said:

It may have been pressure washed coming back from overseas.

As @vrzff points out, fuel and air are now the prime candidates, and as the injector was working well before, I would be inclined to suspect that the muffler is clogged or obstructed. I would give your engine a few hours to settle the rings in, before pushing it to the limit. From here, it seems pretty good. I would run it at whatever load it can handle for a few hours and then try raising it a bit and repeat. If it gets hot, it might start spraying glowing or flaming carbon, so I would do the test somewhere that spraying embers won't cause fire issues.

All the best,

2PbFeet

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You meant for me to reattach the exhaust and run for hours at whatever load it will take without smoking?
Oh I called the machine shop and asked them if they checked and adjusted the ring gap. I assumed they would since the told me they had a ring grinder when I took it to them. They didn't so I might have that problem too.
I should always check everything. This is how you learn.

The exhaust looks pretty good on the outside and what I can see from the ends. The wrap is in pretty bad shape.

Pics

Get a dry, clean, empty milk gallon jug.

Pull the supply line off the injector feed side of the filter. Attach a tube long enough to get into your jug. Flip the switch to prime, and that jug should be pretty close to half-full within 60 seconds and have a decent spray with each pump stroke.

If the spray is weak, or feeding very slowly, start looking at the filter, strainer (little metal can attached to the filter), and finally the pump itself. If you get to the pump itself, the main pump and aux pump are interchangeable-- switcharoo.

Another thing to try is pull the return line post injection pump and injector. Put that into your jug (with everything else connected properly) and start / run the engine. You should still be getting damn near 1/2 gallon a minute returned on idle.

I need to tear the engine apart and check and or adjust my ring gap. Ugh. It's my fault but the owner of the shop wasn't happy his guy hadn't done that when they bored or the cylinder. They had the piston and rings and I assumed. I'll play around with the fuel pump flow also. It is a new fuel pump and filter but that doesn't mean they are good. I've about changed everything on this thing. Funny thing one of my pretty peeves is parts changers. I guess the fuel pump died and the fuel filter you never know. All the other stuff seemed necessary or easy and cheap enough not to matter at the time. Now it's personal. I have to win now!!

Ha ha. I just reread my message about taking the exhaust off. Hard to follow. I'm sorry guys I write terrible. I ran the gen with no exhaust and it ran good. I did it a couple times and the one was about 15 minutes at full load. I see i said I gave it new air. New air filter i meant. I wrote the message and I have a hard time following it.
I think I wrote about the ring gap not being checked at the machine shop but I thought it was then didn't send it I guess so that's what that's about. I thought they checked and adjusted the ring gap but found out they didn't and I didn't either so I definitely need to do that.

Pbfeet seemed to follow at least some of that. I'm thinking the exhaust might be clogged. (I'm hoping now) I'm not sure are you saying it will clear itself with time? Can I try sloshing acetone around or something?

I will try to be more clear and read before I send.

grywitt said:

Ha ha. I just reread my message about taking the exhaust off. Hard to follow. I'm sorry guys I write terrible. I ran the gen with no exhaust and it ran good. I did it a couple times and the one was about 15 minutes at full load. I see i said I gave it new air. New air filter i meant. I wrote the message and I have a hard time following it.
I think I wrote about the ring gap not being checked at the machine shop but I thought it was then didn't send it I guess so that's what that's about. I thought they checked and adjusted the ring gap but found out they didn't and I didn't either so I definitely need to do that.

Pbfeet seemed to follow at least some of that. I'm thinking the exhaust might be clogged. (I'm hoping now) I'm not sure are you saying it will clear itself with time? Can I try sloshing acetone around or something?

I will try to be more clear and read before I send.

Click to expand...

Ok, oopsie on the rings, it happens. Fix that and see where you are. Although, from what you are describing, I think you are basically there.

Yes, I was concerned about carbon clogging the muffler from some of your earlier photos. The inside of the end of the muffler now looks very clean to me, so I would wait on that one. In fact, it seems to have less carbon in it now than before. With the muffler off the engine, you could try a small burst of compressed air from the end back toward the engine. Don't go wild. Mufflers aren't particularly robust. I'd be prepared for some amount of carbon, so I would not do that inside, and I would not point the end anywhere that you care about, just in case, especially anything electrical. While water and alkaline detergent can move a little bit of loose soot, not much actually dissolves carbon (soot) well, and most of the things that do ok with dissolving it or suspending are toxic or corrosive to the point that I wouldn't pour them into a muffler, hence, the recommendation to load up the engines and run it for a bit with the muffler on. From what you have described, you can get the unit pretty loaded, and I would run it at whatever level it can hang in there for

My experience with generators generally, but especially the smaller Yanmar based ones is that, yes, they do not like to have 100% of their load dropped on them at once. Larger versions with more moving mass and large windings have more tolerance for and ways of compensating for, sudden load changes, but I think a lot of it is just physics. The 831 doesn't have a great deal of rotational mass, it is a single cylinder, plus it is an inverter model, so I think that it is just intrinsically going to have a harder time with 0-100% changes in load.

All the best, 2PbFeet

2Pbfeet said:

Ok, oopsie on the rings, it happens. Fix that and see where you are. Although, from what you are describing, I think you are basically there.

Yes, I was concerned about carbon clogging the muffler from some of your earlier photos. The inside of the end of the muffler now looks very clean to me, so I would wait on that one. In fact, it seems to have less carbon in it now than before. With the muffler off the engine, you could try a small burst of compressed air from the end back toward the engine. Don't go wild. Mufflers aren't particularly robust. I'd be prepared for some amount of carbon, so I would not do that inside, and I would not point the end anywhere that you care about, just in case, especially anything electrical. While water and alkaline detergent can move a little bit of loose soot, not much actually dissolves carbon (soot) well, and most of the things that do ok with dissolving it or suspending are toxic or corrosive to the point that I wouldn't pour them into a muffler, hence, the recommendation to load up the engines and run it for a bit with the muffler on. From what you have described, you can get the unit pretty loaded, and I would run it at whatever level it can hang in there for

My experience with generators generally, but especially the smaller Yanmar based ones is that, yes, they do not like to have 100% of their load dropped on them at once. Larger versions with more moving mass and large windings have more tolerance for and ways of compensating for, sudden load changes, but I think a lot of it is just physics. The 831 doesn't have a great deal of rotational mass, it is a single cylinder, plus it is an inverter model, so I think that it is just intrinsically going to have a harder time with 0-100% changes in load.

All the best, 2PbFeet

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Copy that. I push some air back and forth through the muffler until puffs of carbon weren't coming out. I couldn't get to crazy with air pressure and flow since I only have a milwaukee 18 volt air compressor. I took the engine apart today and the rings were out of spec but not to tight. A hair loose but barely. The cylinder wall was already smoothing out in the same two spots. I went and got a ball hone to put the crosshatch back again.

So I couldn't help myself I had a complete engine and one stripped down to the block and a generator to reassemble. I took the sensors off the old one bolted the PMG and muffler to the new one and swapped fuel lines to the new engine then started reassembling the old one. The new one i think is brand new. It's preservation date and manufacture date are 2013. The reason it was in the crate was pull cord wouldn't retract. This was true I had to fix that.

I've got most of the old engine back together now. I filled the new Gen with oil and deciding if I want to assemble the shell again or try it for a few hours first. I think my last liked part of this is the generator skin.

I will do like you say and run it at partial load for a while and bring it up as I can in steps. Even with the new engine if the exhaust is an issue I should still have less than perfect performance.

I'm sure i will get curious about the original engine soon and have to try it again too. The PMG is hard to get on and off that shaft it has some pretty good gouges and scrapes on the tapered shaft. I found out how easy it can go on today when putting it on a shiny new shaft. I did try to clean the original one with sand paper and scotch pad but it's still rough.

Thank you again for the support while I get my butt kicked by this thing. I'm used to winning much faster. Ha ha.

Forgot to add pics again