# Stihl chainsaw chain continually tightening.



## Daniel Holzman (Mar 10, 2009)

I have a Stihl Farm boss saw, and have not had this issue. The chain will tighten up after the saw heats up, presumably because of expansion of metal parts, so if you take a cold saw and use it, you need to readjust the chain tension. But I only have to do this once, when the chain drive gets hot. Not sure what type of saw you have, but it does not sound correct, and I am not aware of any adjustments you could make. Sounds to me like your tensioner is malfunctioning.


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## 47_47 (Sep 11, 2007)

As previously mentioned, the bar expands as the saw heats up and makes the chain tighter. 

When tensioning the chain are you picking up on the bar, before locking it in place?


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## daveb1 (Jan 15, 2010)

You say you "push" the bar back in? There should be some type of adjustment after you loosen the bolts. Check your manual on replacing the chain and be sure you are tightening and adjusting the chain properly.


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## joed (Mar 13, 2005)

There should be a screw on the front of the saw to adjust the bar.


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## daveb1 (Jan 15, 2010)

My small Stihl (MS180) with some type of easy adjust has a black thumb wheel to adjust the bar after the side bolts have been loosened.


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## gregzoll (Dec 25, 2006)

Roasted, which model do you have? I have the same model as Daveb1 has, and never have issues with it tightening. Now of course you do have to adjust slack over time. Because the chains will stretch.

If you are running the saw a lot, and heating it up, it can cause it to tighten or loosen, depending on how you are using it.


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## gregzoll (Dec 25, 2006)

daveb1 said:


> My small Stihl (MS180) with some type of easy adjust has a black thumb wheel to adjust the bar after the side bolts have been loosened.


I have the same model. Runs like a charm. I actually got smart and went with a Carbide Tipped chain, along with the 16" bar.


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## nanuk (Aug 14, 2011)

Are you sure it is getting enough oil?
Aim at a cardboard and see how much oil it spills when running at high speed.


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## Bondo (Dec 8, 2007)

nanuk said:


> *Are you sure it is getting enough oil?
> Aim at a cardboard and see how much oil it spills when running at high speed.*


Ayuh,.... That's 'bout the only reason I can think of, for the chain gettin' tight,...


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## ront02769 (Nov 28, 2008)

Have been running a Stihl MS290 for somewhere over ten years, loosen nuts, tighten up chain, lift bar, and slightly tighten up the nuts. Check for proper tension "and then tighten down nuts. It has never "gotten tighter to the point of being unusable". Looser, yes due to the chain stretching, but not tighter. Possible problem with part of the bar track being compressed from getting caught up in a tree that you were cutting and then tightening down when it heats up? M ore likely the oiler as noted. Ron


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## gregzoll (Dec 25, 2006)

The oiler may be clogged. Time to run some Sea foam through the gas & oil to clean out the gunk. If I let my 180 sit for a long time, with oil in the reservoir. It will leak all over inside the case I keep it in.


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## Tull1980 (12 mo ago)

Daniel Holzman said:


> I have a Stihl Farm boss saw, and have not had this issue. The chain will tighten up after the saw heats up, presumably because of expansion of metal parts, so if you take a cold saw and use it, you need to readjust the chain tension. But I only have to do this once, when the chain drive gets hot. Not sure what type of saw you have, but it does not sound correct, and I am not aware of any adjustments you could make. Sounds to me like your tensioner is malfunctioning.


OK if that bar is expanding enough to tighten the chain you have some major malfunctions because that also means the chain is heating up that much as well to change it heat up and get loose no matter what your bar should not expand their not made to and you might want to three thank you’re still scares not all items in the front Letitia Street mines in the side in the middle of the bar


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## chandler48 (Jun 5, 2017)

@Tull1980 you are responding to an 8 year old thread. Hopefully in that length of time he got his problem solved.


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## Fix'n it (Mar 12, 2012)

Tull1980 said:


> three thank you’re still scares not all items in the front Letitia Street mines in the side in the middle of the bar



wth does this mean ?


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## Tim blah (12 mo ago)

just joined i have a still M5271 18" bar all oil ways clear .i lift tip when i adjust chain .even if i leave loose as possible chain will go tight .to point of unusable. .chain always well lubricated before and after. all i can think is causing this is i am cutting very hard bone oak up to 11" for about 20 minutes. any advice or opinions be great!


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## chandler48 (Jun 5, 2017)

@Tim blah I'd contact Stihl to see if they have a solution. This 8 year old thread isn't going to help much.


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## Tim blah (12 mo ago)

chandler48 said:


> @Tim blah I'd contact Stihl to see if they have a solution. This 8 year old thread isn't going to help much.


makes sense cheers!


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