Where do the sparks that the spark arrestors arrest come from?

[Franny K]

On a serious note (if that is possible): if the sparks are the result of carbon in the combustion chamber, would a richer oil-to fuel mix increase this, or only a richer fuel-to-air ratio? Which would cause more carbon?

Philbert

Probably the higher detergency of the modern oils, the ones that get the ratings a lot of saws are calling for now would help. I do see sparks off the chain when it starts to get dark but don't recall anything coming out with the exhaust. I do have screens but there seems written material on the saw indicating more stuff may be needed.

 

[mdavlee]

The chain smacking the bar at high speed makes sparks from there. The chain isn't making sparks on the wood unless you cuts nails[emoji16]

 

[Philbert]

. . . don't recall anything coming out with the exhaust.

Probably hard to see on your own saw due to the location of the muffler. But I have seen occasional sparks from a variety of gas powered equipment (lawn mowers, generators, etc. run after dark).

Philbert

 

[Gypo Logger]

A very good but subjective question. Some saws with a fatter mix are already fat on the jets. Throw half throttle techniques into the mix and there's a recipe for carbon build up.
Then when you take said saw and lean it to factory specs it usually suffers from a score on the exhaust skirt.

On a serious note (if that is possible): if the sparks are the result of carbon in the combustion chamber, would a richer oil-to fuel mix increase this, or only a richer fuel-to-air ratio? Which would cause more carbon?

Philbert

 

[skipster]

out here in the aussie box ironbark forest,I've noticed quite a lot of sparks off the bar and chain.
Always thought it was minute particles of quartz in the bark (termite deposits etc) that did it,but the bar bouncing off the chain is more likely,as suggested above.

 

[mdavlee]

out here in the aussie box ironbark forest,I've noticed quite a lot of sparks off the bar and chain.
Always thought it was minute particles of quartz in the bark (termite deposits etc) that did it,but the bar bouncing off the chain is more likely,as suggested above.

It could be from the deposits. I know a rock makes lots of sparks too.

 

[old guy]

I don't think it is sparks as much as the flame of burning fuel being pushed out the exhaust port.
I remember many times watching the heat from the front port on the muffler actually start dry oak bark on fire on long cuts where the muffler stayed in the same place while I rocked the bar through a big log, I don't remember what saw that was but it had louvers in the front of the muffler.

John

 

[Philbert]

I remember many times watching the heat from the front port on the muffler actually start dry oak bark on fire . . .

"Exhaust gases and carbon particles may be expelled from the engine block at temperatures exceeding 3,000 °F. Exhaust system surfaces can reach temperatures of 1,000 °F. Wildland fuels, however, can ignite at temperatures of only 400 to 500 °F. With these figures in mind, it is evident that fires can be started by wildland fuels coming in contact with hot exhaust gases or from contact with the hot surfaces of the exhaust system." USFS document

Philbert

 

[1Alpha1]

Sparks = red hot pieces of carbon off the piston.

 

[Bwildered]

when cutting low stumps in sandy soils sand is deposited up the bark by driving rain, guaranteed to see sparks off the chain in broad daylight no matter what the timber is.
thansk

 

[Gypo Logger]

I'm wondering what sparks one would see if you put straight gas in the oil tank. Lol.

 

[Bwildered]

I'm wondering what sparks one would see if you put straight gas in the oil tank. Lol.

You would see the last ones!
Thansk

 

[wde_1978]

Today I came across the following video and was amazed how much "fire" that thing is spitting!

 

[sawfun]

The chain smacking the bar at high speed makes sparks from there. The chain isn't making sparks on the wood unless you cuts nails[emoji16]

The chain sparks are generally from the rails, I can see that visibly at times.

The exhaust sparks are carbon or more to the point, unburned fuel now seen as burning that was attached to or trapped by the carbon particle, likely from the oil and possibly, but only possibly, piston or other material.

If the Forest service doesn't like sparks I wonder how they would feel about the fire exiting the muffler on a KMS-4.

 

[Full Chisel]

Today I came across the following video and was amazed how much "fire" that thing is spitting!

My 372 throws sparks just like that...

 

[wde_1978]

My 372 throws sparks just like that...

If I remember , I'll have to remove the spark arrester on my PS-6400 or even better PS-7900 if I ever find myself cutting at sundown and pay attention whether they spit sparks as furious as that.
I never noticed any sparks finding their way through their spark arrester.

The chain sparks are generally from the rails, I can see that visibly at times.

Agree , to a point!
When I first mounted a new bar & new chain with a 8 tooth sprocket on my PS-7900 sparks were carried all around the bar by the chain visibly in broad daylight.
I stopped cutting several times to check whether the chain is catching on to something.
Thankfully it stopped after a few cuts , and yes there was sufficient oil on the bar/chain.

 

[OldJack]

The biggest shower of sparks comes when the saw is idling while he drives the wedge.

 

[Full Chisel]

Mine has a screen installed and still throws sparks...I would imagine a faller's saw would have one installed as well. I don't think they prevent sparks, they just knock down the particle size to an acceptable and safe size.

 

[BGE541]

Science shows sparks come happen when a coil and a sparkplug really really like eachother. You all are just trolling, mods shut this thread down LMAO

 

[huskihl]

The biggest shower of sparks comes when the saw is idling while he drives the wedge.

That's what she said