loosen chain

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Former Saw Builder

Former Saw Builder

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Who loosens up their chain at the end of the day?

My new MS 880 manual said your supposed to slacken the chain when your done cutting for the day to keep from screwing up the bearings and crank...

I've been running saws for years and never did this so far... Wondering how important it was.
Is it a new saw thing. or have I been screwing up my saws for the past 35 years?
 
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bcorradi

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If your not one to run an overtightened chain I think relieving the tension before storing it is neglible. The only time your putting unneeded stress on the crank and crank side bearing is when you have an overly tight chain.

I assume you meant 880?
 
woodchuck361

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Only if I tightened the chain while it was hot. I.E. after running awhile. The stihl chain does not stretch much and I usually have to sharpen the chain before the chain needs tightened. I ran all day sat. never tightened the chain never had to sharpen, Cut 4 large hickories, one very large popular and several oaks.
 

Gark

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I loosen it everytime before overnight storage and today I saw why. Was running an old saw with manual oiler and got overzealous with the thumb oil pump while cutting. Ran the oil tank dry without knowing it and noticed loose chain. Bar was warm, chain was hot and I watched as the drooping bottom loop (hanging down an inch below the lower bar groove in middle of 20' bar) cooled and pulled itself right back up into the drive link channel. Took 4 minutes for the chain to cool and contract. If the chain can contract that much with temperature change, imagine how tight it can get if stored in real cold temps.
 
woodchuck361

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I watched as the drooping bottom loop (hanging down an inch below the lower bar groove in middle of 20' bar) cooled and pulled itself right back up into the drive link channel.

I have never seen the chain hang down that far. How could you cut with a chain that out of adjustment? What kind of chain are you using? I would switch to another chain or brand.
 
Former Saw Builder

Former Saw Builder

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If your not one to run an overtightened chain I think relieving the tension before storing it is neglible. The only time your putting unneeded stress on the crank and crank side bearing is when you have an overly tight chain.

I assume you meant 880?

Yeah that was a typo.... I fixed it...
 
cuttinscott

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PLEASE if you bring your saw to a SHOP to have it serviced PLEASE have the chain and bar tight!!!!!!!!!!!! I had a guy bring me a saw said it wasn't running right so I started it and wammo the side cover fell off. Was a SXL homie and the chain almost got me. PLEASE KEEP YOUR BAR AND CHAIN TIGHT.


Scott
 
B_Turner

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Especially with bars >32 inches I do my usual routine. First thing before running saw for the day I fuel/oil the saw, and then start it and run it several seconds. Then I adjust the chain, generally adding some tension. Periodically I check the tension throughout the day, and adjust as needed. New chains the same, run a little bit and then adjust.

At the end of day I then take off a little tension, especially if I have had to tighten during the day. For example with my 066 and 42 inch bar, if I don't slacked the chain a little, the chain can be pretty snug when cold.

If you have ever looked at the math to do with tension when trying to pull a rope up to horizonal (remove sag), the forces are pretty great. I run my chains fairly snug, both for bar wear reasons and safety reasons.
 
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stihl 440

stihl 440

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chain slackening

I never worried about it ,but then again I don't overtighten my chain and my chain is always sharp.:greenchainsaw:
 
wood4heat

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I've had a strange thing happen I've never understood. I've got a MS361 with a 25"es bar. The chain is sharp, throws oil and I believe adjusted properly. My first time using the saw the chain got so tight it was bogging the saw down. I loosened it and the same thing happened again. The bar was warm but not hot. Went back to loosen it again and noticed I had a flat on my trailer, no spare. Ran home for a spare and by the time I got there the chain had loosened back up to the point of being sloppy.

First I thought it wasn't getting oil but as I said the chain would fling oil off the tip.

Next I thought chips were building up under the sprocket but that didn't seem to be the case.

I don't run my chain as tight to start now but this has happened a couple more times. Originally I adjusted it to where it wouldn't pull out of the bar channel but I could spin it easily by hand. Now I run it so that it sags about 1/8" off the bar on its own and can be pulled out of the channel. Was I running the chain too tight to start? The bar didn't feel overly hot but could it be expanding making the chain tight? Anyone ever heard of anything like this?

Oh and to the point of the post I don't loosen my chain during cutting season but do when I put it up for winter.
 
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romeo

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On the bike saws I will set the chain on so tight that it will barely spin. Run it for 10 or 20 seconds and it will be hanging down 1/2" in the center of the bar. Then tighten it up again while its hot. When I am done with the run I pull the chain so I don't bend the crankshaft when it shrinks. This is very extreme for saw chain, most folks wont notice that much stretch.

I have seen saws tighten up when they get hot, it has to be the bar generating heat. The only saws I have seen do this were brand new BTW.
 
wood4heat

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I have seen saws tighten up when they get hot, it has to be the bar generating heat. The only saws I have seen do this were brand new BTW.

It was a brand new saw when this was happening and the bar was warm but not hot. It hasn't done it in a while which I attributed to running the chain a little looser but now you got me thinking with the brand new saw comment. I would imagine the sharper a chain is the cooler it will stay. Well the chain on this saw was so sharp when I got it I couldn't put the bar sleeve on without the chain slicing holes in it. could the bar have heated up faster than the sharp @ss chain when new but now that it's got some use they heat up more evenly? I hand file the chain and it cuts great but it isn't nearly as sharp as it was new.

Another thought, this happened up on Mt St Helens in the spring and it was fairly cold. Can wood get cold enough to cool the chain? And yes I know I come up with some off the wall **** sometimes. :buttkick:
 
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GASoline71

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On the bike saws I will set the chain on so tight that it will barely spin. Run it for 10 or 20 seconds and it will be hanging down 1/2" in the center of the bar. Then tighten it up again while its hot. When I am done with the run I pull the chain so I don't bend the crankshaft when it shrinks. This is very extreme for saw chain, most folks wont notice that much stretch.

I have seen saws tighten up when they get hot, it has to be the bar generating heat. The only saws I have seen do this were brand new BTW.

I run the chain on the Termite very tight as well. When it heats up it will stretch and hang off the bottom of the bar.
 
MikeInParadise

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I never loosen them off at the end of the day.

I have notice a big difference in sag between the Oregon chains and the Stihl RS chain that I prefer. I have never noticed the Stihl RS sagging but I have noticed that I have to adjust the tension on the Oregon chains. In addition I seem to have to sharpen the Oregon chain more often.
 
Sprig

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Hm, never really loosen them, and don't run them real tight (pull gently till driver almost out of bar etc), if they're gonna sleep for a while I'll pull the b&c off. I will check tension before starting, and adjust accordingly, esp. if its a new chain that has been tightened over the day. The comments on messing with bearings an' crank now has me thinking of paying a bit more attention to this though, hm. Curious Q here, I wonder what amount of bar expansion happens? As has been discussed several times in a number of threads, 'stretch' on a new chain isn't actually stretch per-se but the rivets breaking in, I'm inclined to agree with those that pointed this out, but its a given that a long chain with hot work will get a bit sloppy imho, but maybe 'expansion' is a better term than stretch. dunno, just a though fer the miserable wet evening.

:cheers: +2 or three, hey, it sux out there tonight and my glass is full :D

Serge
 

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