I think I got my chiansaw (ms 441 cm) too hot cutting lighting struck oak...

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anymanusa

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I haven't used it in a good while and I had a really big tree (40" x 28" diameter or close to that). I was doing some limbing with my shorter 18" bar and it was cutting like butter. When I got to the trunk I put my 24" bar on and was having a really hard time, or slow time with it. It just wasn't cutting as well and I kept pulling it out to hear the gurgle sound and make sure it would 4 stroke so as to make sure it wasn't running lean and getting hot, but the bar was getting hot, the saw was working hard.

Then all of the sudden it dawned on me that I hadn't turned the oiler up for the big bar. Doh.

Cutting was alot easier after that. Still slow though, that chain probably wasn't as sharp as it could have been.

I'm really worried that I scored up the piston. I use the stihl synthetic oil in excess of the recommended 50:1 and the saw ran strong the next day when I used it...I just feel dumb and like I did some damage to it.

Here is the best pic I could get on short notice. This is looking in through the exhaust port with the muffler removed.


full
 
I'll check it for scoring soon. The piston had light scoring from the prior 12 years of my ownership for some reason. I noticed last time I removed the muffler. I'm glad it still feels strong.
 
if you had light scoring 12 years ago , i think you have done well, might want to replace the piston , unless you all ready have .....Any scoring is not good ... and o.e.m. cylinders are not cheap
I'll post pictures when I can, that way we're all on the same understanding.
 
Take a look at the lightning-struck pin oak I had to take out. Indirect lightning could have hit this tree a dozen or more times in one storm. Every branch had a cross section that looked like this:
Pin Oak Tree5.JPG
That stump is 36" across. The tree was over 40' tall. After it was hit in early spring, she never again produced a leaf. The leaves you see here fell from an ash tree in the following fall. Sometimes mother nature has no mercy.
 
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I hope I'm being overly pessimistic about this, and that this really isn't anything at all. To me it looks like the bore is glossy shiney for the most part, but it has some streaks down it on the intake side.

Also an update, the piston has no visible marks at all when viewed from the exhaust port.
 
what does the piston skirt look like ?,it's best to remove the cylinder for a complete look
Do you think what you see warrants that? I'm hesitant to break into a strong running saw. Can I do some longevity work to it just by taking the jug off? Is that where you're going with this?
 
So, how did the oak hit by lightning get into the picture and the post title? Seems rather odd to me. You could have been cutting poplar, cottonwood, or linden. Right?
I just mentioned it because it wasn't a tree we wanted to take down but had to. It was dead and brittle and the bulls stayed under it.
 
Other than cutting a big tree and working the saw, why are you worried you damaged it? Did it ever act "lazy", did you hear any detonating (preignition), or any obvious signs it ran hot or lean? What does the sparkplug look like? Is it a nice tan / brown? Does it look white / gray and have any metal specks on it?

If none of those things happened you probably didn't do any harm. I've blown up / damaged some 2 strokes and it was always caused by:

- Overheated - obvious loss of power
or
- Ran lean
 
Other than cutting a big tree and working the saw, why are you worried you damaged it? Did it ever act "lazy", did you hear any detonating (preignition), or any obvious signs it ran hot or lean? What does the sparkplug look like? Is it a nice tan / brown? Does it look white / gray and have any metal specks on it?

If none of those things happened you probably didn't do any harm. I've blown up / damaged some 2 strokes and it was always caused by:

- Overheated - obvious loss of power
or
- Ran lean
What do you think about the bore? Is that troubling marks?

I've heard that some of the early 441cm models needed a program reflash for lean issues.

It doesn't feel weak, I was concerned because it ran too hot and worked too hard for a spell.
 
Take a look at the lightning-struck pin oak I had to take out. Indirect lightning could have hit this tree a dozen or more times in one storm. Every branch had a cross section that looked like this:
View attachment 778824
That stump is 36" across. The tree was over 40' tall. After it was hit in early spring, she never again produced a leaf. The leaves you see here fell from an ash tree in the following fall. Sometimes mother nature has no mercy.
Odd... Looks like "ink" from metal.
The wood I mean
 
What do you think about the bore? Is that troubling marks?

I've heard that some of the early 441cm models needed a program reflash for lean issues.

It doesn't feel weak, I was concerned because it ran too hot and worked too hard for a spell.

If it was my saw i wouldn't worry about it, doesn't look like scoring as much as some light scuffs.

I would not worry about your saw running hot, the cooling fins look nice and clean.

I'd just run it.
 
I ran it again with that bad chain, forgetting that there was something wrong with it, and felt like I worked the saw too hard again. I resharpened the chain, hit the rakers and inspected the bore again and it looks like those scuff marks are completely gone now. I thought they'd be there forever.

I hit barbed wire with that chain about 10 years ago, and it's been abused and I haven't cared for it properly. I'm gonna retire it to back up use only and buy a new chain.

20220327_173147.jpg
 
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