When to worry about black smoke?

[etpm]

My YM2310 starts fairly fast even in cold weather and the Thermostart is broken. In warm weather it starts almost instantly. I recently got my tiller connected and when tilling at about 2000 RPM I can see some black smoke coming out of the exhaust. Not tons but I can see it. If I raise the RPM a little, to maybe 2100 RPM, the smoke decreases. If I let the RPM drop to about 1800 RPM when engaging the tiller fully in the ground and tilling the smoking will increase. It looks to me like a big increase. But what do I know? This is my first diesel machine. And the machine is 42 years old after all.
When doing other chores with the tractor which put less load on the tractor it really doesn't smoke much. And I know this is also a subjective thing. So, is there any thing I should be concerned about?
Before I bought it late last summer the seller said it had been sitting for two years without being started. The vegetation that had grown around it and the rodent nesting activity around the gas tank were also indicators that it had been sitting idle for some time. The seller told me he put the battery on a charger but that it wouldn't turn over and that I was welcome to figure out why. If I could get it to turn over he would sell it to me for the agreed price. I figured out the electrical problem and the thing started up almost instantly. It was hot that day, probably about 90 degrees. I used the directions in the manual and was so surprised by the quick start that it took me longer than it should have to back the throttle off to 1000 RPM.
So the upshot is that the tractor starts and runs well and is owned and operated by someone who is pretty ignorant when it comes to practical diesel engine operation. I do use some sort of additive that is supposed to clean the injectors and increase the cetane. Maybe that's why it starts in cold weather here, about 30 miles north of Seattle. Since I bought the tractor near the end of last summer I have only put about 35 hours on the tractor, so maybe the moose pee I have been adding to clean the injectors needs a little more time to work. Or maybe everything is OK and I'm concerned about nothing.
Anyway,
Thanks,
Eric

 

[bmaverick]

Eric, what engine oil is in the machine? 10W30 allows the engine to move better and there is way less smoke vs. the problems with the 15W40 in compact tractors like ours.

Are you also running the tiller on virgin ground and at a too much of a depth to increase load on the PTO and engine?

Do you see less soot smoke out the exhaust when tilling and the tractor moving slower?

Either the tractor is working too hard, has the wrong oil for the engine use or it's moving too fast for the tiller and engine to keep up while under load.

Lastly, how often does the machine run over 1600RPMs for over 10mins? And with the YM 3-digit machines, the OPS manuals state not to let the engine idle for more than 10mins that can cause soot build up in the exhaust system.

Welcome to owning a diesel. Yes, there is a certain knack to using it all. You did well not to operate at the higher end of the RPM band for the machine.

 

[winston1]

Sounds normal to me. The more you load them the more they will put out black smoke. Black smoke is unburned diesel. Your governor opens up the strokes on the injection pump when rpms begin to drop and if engine is overloaded the cylinders are unable to have a complete burn of the fuel and the result is black smoke.

 

[careyo63]

I only load up with much of any smoke unless I Bogg the mower wet grass etc. but clears right up when I get through it. When I tilled not much at all only Starting up. Nothing like this Pic. First season pass and low as it will go. Real deep with no Depth wheels.

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The smoke clears right up even today.. I use to get Oil bombed/Carbon though. Had to clean the Exhaust out a couple times. Took care of that problem with just gas and the Air compressor.......

 

[ponytug]

@etpm Yes, diesels smoke (a little) when loaded, and heavy tilling is definitely loading. Running the engine so that it isn't smoking heavily is the goal. So, increase the rpm's, or reduce the load or both. "Moose pee" will help clean the injectors, which will help all of the fuel get burned cleanly, which will reduce smoke. If the prior owner lugged the engine a lot, or only used the engine briefly and never got the engine hot, there will be carbon on the injectors and cylinder walls that will slowly get burned off as you use it more, and for longer periods when hot.

For older diesels like ours, "moose pea" cetane additives are essential. (Love that description!) I have used most of them and can't really tell the difference (SeaFoam, Power Service Diesel Kleen, and I am currently using Opti-Lube summer+), with one exception. Diesel Purge from LiquiMoly did really clean out my diesels and noticeably improved the clean burning, despite having always bought quality diesel, and always running one of the three other additives. It is best to use Diesel Purge straight by running the fuel line into the can, failing that, put a new fuel filter on, prefill the bowl with Diesel Purge, and put the rest the Diesel Purge in your fuel tank, when the tank is relatively empty. Try to run it with the engine running wide open; I find mowing to be a good use. As this tractor is new to you, would file it under the probably worth doing, can't hurt category.

It also never hurts to double check your air filter, but is suspect yours is new within the last 35 hours.

... I use to get Oil bombed/Carbon though. Had to clean the Exhaust out a couple times. Took care of that problem with just gas and the Air compressor.......

Sounds interesting! Can you elaborate?

All the best,

Peter

 

[4get gto]

Don't know if it was talked about already but check the air filter out. Lord knows what that may look like..

 

[etpm]

Eric, what engine oil is in the machine? 10W30 allows the engine to move better and there is way less smoke vs. the problems with the 15W40 in compact tractors like ours.

Are you also running the tiller on virgin ground and at a too much of a depth to increase load on the PTO and engine?

Do you see less soot smoke out the exhaust when tilling and the tractor moving slower?

Either the tractor is working too hard, has the wrong oil for the engine use or it's moving too fast for the tiller and engine to keep up while under load.

Lastly, how often does the machine run over 1600RPMs for over 10mins? And with the YM 3-digit machines, the OPS manuals state not to let the engine idle for more than 10mins that can cause soot build up in the exhaust system.

Welcome to owning a diesel. Yes, there is a certain knack to using it all. You did well not to operate at the higher end of the RPM band for the machine.

I don't remember which oil I used right after I bought the machine but I think I used 10W30. I will be changing the oil again next week though and will be using 10W30.
The ground tills pretty easily so I don't think the load is excessive. I am running the tiller at full depth which is really only 4 or 5 inches. With RPM at 2000 it drops to about 1750 once tilling starts. The tractor is in first gear on the main transmission and first gear on the Powershift transmission. So the tractor is not moving forward very fast. I see more soot at 1750 than 2000. So I apply more throttle to get the RPM back to 2000 and the smoke decreases quite a bit.
I have read here on TBN different recommendations about how long and at what RPM to idle at. But I never idle above 1500 RPM.
One more thing that I should add. I read about "Wet Stacking" here and looked it up. And I have been seeing some signs of it I think. Around the end of the exhaust pipe I see evidence of wetness. Since I had been idling the engine at about 900 RPM I thought this might be the reason why so now I idle at 1000 or 1100 RPM.
Thanks,
Eric

 

[etpm]

@etpm Yes, diesels smoke (a little) when loaded, and heavy tilling is definitely loading. Running the engine so that it isn't smoking heavily is the goal. So, increase the rpm's, or reduce the load or both. "Moose pee" will help clean the injectors, which will help all of the fuel get burned cleanly, which will reduce smoke. If the prior owner lugged the engine a lot, or only used the engine briefly and never got the engine hot, there will be carbon on the injectors and cylinder walls that will slowly get burned off as you use it more, and for longer periods when hot.

For older diesels like ours, "moose pea" cetane additives are essential. (Love that description!) I have used most of them and can't really tell the difference (SeaFoam, Power Service Diesel Kleen, and I am currently using Opti-Lube summer+), with one exception. Diesel Purge from LiquiMoly did really clean out my diesels and noticeably improved the clean burning, despite having always bought quality diesel, and always running one of the three other additives. It is best to use Diesel Purge straight by running the fuel line into the can, failing that, put a new fuel filter on, prefill the bowl with Diesel Purge, and put the rest the Diesel Purge in your fuel tank, when the tank is relatively empty. Try to run it with the engine running wide open; I find mowing to be a good use. As this tractor is new to you, would file it under the probably worth doing, can't hurt category.

It also never hurts to double check your air filter, but is suspect yours is new within the last 35 hours.


Sounds interesting! Can you elaborate?

All the best,

Peter

The air filter looks great. Though it is the one that was in the tractor when I bought it it still looks clean. Or, I should say, looked clean when I bought the tractor. I took the filter element out and a visual inspection made me think the filter was recently installed and barely used. Nevertheless I used compressed air to blow it out from the inside and hardly dust blew out. I read about Diesel Purge after seeing your post and I'm gonna buy some and give it a try.
Thanks,
Eric

 

[etpm]

Well folks,
I will be changing all the filters and oils in the next week or so. It depends on how wet it is outside. Since the tractor was bought used I thought an immediate oil change was a good idea and then a subsequent one a little while after just to make sure any old stuff remaining and other crap gets removed. Even though the hydraulic oil looks good all sorts of folks want to spend my money on a new batch of the stuff and I'm gonna capitulate just so I don't have to feel guilty about lying and saying I changed out the oil when I didn't. Even though the oil looks great. It isn't discolored, doesn't show any signs of water, smells like fresh oil, tastes good, doesn't smoke when I'm making tempura earth worms, makes my skin silky smooth, etc. But I am gonna change it anyway.
So after I change the oil and fuel and air filters and run the Diesel Purge moose pee through the engine I will report back on the smoking situation. My feeling is the tractor just needs a good internal cleaning and new fluids.
Thanks everybody for the help, I really appreciate it,
Eric

 

[yanmars]

My 336D smokes a bit under load and has for over 30 years. Seems pretty normal to me.