Soot

[East_TN_EMC]

I have a 790 with about 90 hours on it. It is a great tractor and does all I need of it.
I have noticed lately that after cutting the field (about 15 acres) that it is covered with a fine coating of black soot, very similar to what is left in a candle jar after the candle has been buring for a while.

Any ideas where this is coming from?

Thanks.

 

[fgross335_2210]

Sounds like it's from the exhaust. Are you running highway fuel or off-road stuff. The off-road stuff is typically quite a bit higher in sulpher contributing to more exhaust soot.

If it is exhaust soot you might try running an additive such as Stanadyne, most addtitives are advertising as reducing soot (along with a number of other benefits that aren't visible but probably more important).

 

[_RaT_]

My neighbors does the same thing. It's been mentioned before by other owners. We only have low sulphur fuel here in CA so thats not it. I think it's just inherent in the engine design. I spoke to my neighbor about turning his exhaust down. He wasn't sure about doing that as the smoke/soot does not really bother him. But what does he know, he also smokes and doesn't smell how bad his home smells either. /forums/images/graemlins/shocked.gif

 

[5030]

I don't agree with the on-road-off road diesel scenario.

If the engine has the proper air/fuel ratio and the pump pressure and injection timing is correct, you would be getting very little soot regardless of what type of fuel you are running.

Factors such as lugging the engine will elevate the soot level as the engine isn't burning cleanly.

To that end, the first thing I'd check is the air filter or pre-filter. I clean my pre-filter every time I use my 5030 in the field. Brush hogging or any type of mowing will cause the air cleaner to plug up quickly. Mowing also causes a heavy load on the engine. I think probably that your pre-filter is loaded with chaff causing the engine to run with a less than ideal air/fuel ratio. While you are at it, clean the radiator screens. Your tractor will apppreciate it. /forums/images/graemlins/smile.gif