Shower of sparks from exhaust

[Jay4200]

I was clearing snow Friday night in the dark, and was pushing my Kubota L4200 pretty good. There was about 10" of heavy stuff, I was WFO at PTO speed or slightly better, probably a gear higher than I should've been, and going uphill. As I finished my ~400' hill, I noticed sparks coming out of my exhaust. Not like a couple here and there, but a crapload - like somebody was running a grinder in the engine compartment. I stopped working and slowed the engine down - after a minute or so the sparks stopped coming out. The engine sounded fine the whole time, and everything else seemed OK, so I continued on, although I took it a little easier. No more sparks came out after that. I'm hoping I was just burning carbon out of the exhaust can.

Does any of this sound unusual? I've never really run at night before, so maybe sparks come out frequently and I just never saw it before?

JayC

 

[tcartwri]

You may have ignited some of the packing in the muffler.

 

[vtsnowedin]

I've seen that before at night when working the bejesus out of a tractor. All the carbon that built up on the exhaust valves and in the exhaust manifold when it was idling or doing half throttle work falls off when the metal it is stuck on gets red hot at full load. As long as your oil pressure and coolant temps are in line I don't think you have much to worry about and it may even run better after a good cleaning out.

 

[Don87]

My dealer claims it's carbon buid-up in the muffler from running at too low of rpm's for too long of a time. He said to be sure to go to WOT occasionally to keep it clear(like what you experienced).

When I was having issues with mine, that was the first thing he checked, but mine was clean.

 

[Cub 7274]

Some of the old GM locomotives we used to use would light up the sky at night with exhaust showers even causing the odd grass fire along the right of way in the dryness of the summer and it was because of carbon build up.
You didnt want to be anywhere but in the cab when it was real bad as you would be covered in soot

 

[Jay4200]

Thanks all. Oddly, I pretty much always run at WFO - at least in the winter while running my snowblower. I guess that creampuff engine I have is still loafing when I'm thinking I'm working it. I guess I need to beat on it even harder...I can't wait.

 

[Gary Fowler]

I have ran big farm tractors (100+ HP) at night pulling heavy loads and the muffler will be glowing red with sparks blowing out occasionally. Nothing to worry about. Engine loafing around builds up carbon and normally muffler doesn't run that hot till you load the engine and then it heats up and will burn out the carbon build up. Even running WOT (wide open throttle) without a load doesn't heat up the exhaust, it has to be loaded also.

 

[Gary Fowler]

Thanks all. Oddly, I pretty much always run at WFO - at least in the winter while running my snowblower. I guess that creampuff engine I have is still loafing when I'm thinking I'm working it. I guess I need to beat on it even harder...I can't wait.

I have been trying to think what WFO stands for and cant. Please enlighten me

 

[aczlan]

I have been trying to think what WFO stands for and cant. Please enlighten me

Wide _____ Open

Aaron Z

 

[ArtMech]

In my opinion it's not only the carbon from exhaust system which could produce a spark stream. I mean carbon should be ignited by something to make that effect. And that "something" could be fuel. Because at high RPMs and loads here comes a huge enrichment of air/fuel mixture so that not all fuel is being burnt in the cylinders. Part of fuel gets out still burning but inside the exhaust system components and outside. It also ignites internal carbon and its particles. That's why sometimes we may see sparks coming out of exhaust.
Once at the beginning of '80s when I was driving trucks I've got even a fire running out of 10 tons dump truck platform which was heated by exhaust gases. A fire stopped immediately after deceleration. The double bottom of a platform was full of unburnt diesel fuel.