Premature bar wear mystery on new MS 661 C-M

[toadman]

Not to derail the intriguing conversation about the laws of physics...
I wrecked a bar in similar fashion to the OP on my 394 husky when I first got it. it was an eye opening learning experience about high speed wear and powerful saws.
The saw was cutting crooked & I didn't have time to stop and figure out why, (had to get a load of logs on the road in a hurry) so I just muscled it into cutting straight... 40 ish cuts later, I had wore the bar groove on one side to the point the drivers rocked side to side in the groove a lot. It never threw a chain, but it wouldn't cut straight no matter what I did after that.
I was putting less sideways force than the weight of the saw, so I didn't think I was pushing hard enough to damage anything.
Nevertheless, cost me a bar... I have done this as a teenager countless times when I didn't know how to sharpen, but not on a saw that cut that fast, or had that much power.
The saw was running perfectly, oiler maxed on a 28" bar slinging oil fine. That saw oils a 42" without struggle in any wood.
It might be you subconsciously pushing to one side trying to correct for a few rocked cutters, it didn't take me much force, or very long to wreck my bar.
Could be the oiler. Maybe. Worth checking if there's doubt.
Could be crud in the bar rails.
hesitant to believe it is caused by a loose chain... that can cause problems, but it takes a long long time for a mildly loose chain to ruin parts.
As for the physics, I find mine is typically tight in the morning, and requires a few minor adjustments tighter throughout the day. Nothing major with a used chain.
Never gets loose when cold only tighter, but maybe that's just me.

I have to live by the laws of physics now since I don't have a reality stone at my command to alter materials expansion rate... so I don't know how it works for everyone else.

 

[Short timer]

Not to derail the intriguing conversation about the laws of physics...
I wrecked a bar in similar fashion to the OP on my 394 husky when I first got it. it was an eye opening learning experience about high speed wear and powerful saws.
The saw was cutting crooked & I didn't have time to stop and figure out why, (had to get a load of logs on the road in a hurry) so I just muscled it into cutting straight... 40 ish cuts later, I had wore the bar groove on one side to the point the drivers rocked side to side in the groove a lot. It never threw a chain, but it wouldn't cut straight no matter what I did after that.
I was putting less sideways force than the weight of the saw, so I didn't think I was pushing hard enough to damage anything.
Nevertheless, cost me a bar... I have done this as a teenager countless times when I didn't know how to sharpen, but not on a saw that cut that fast, or had that much power.
The saw was running perfectly, oiler maxed on a 28" bar slinging oil fine. That saw oils a 42" without struggle in any wood.
It might be you subconsciously pushing to one side trying to correct for a few rocked cutters, it didn't take me much force, or very long to wreck my bar.
Could be the oiler. Maybe. Worth checking if there's doubt.
Could be crud in the bar rails.
hesitant to believe it is caused by a loose chain... that can cause problems, but it takes a long long time for a mildly loose chain to ruin parts.
As for the physics, I find mine is typically tight in the morning, and requires a few minor adjustments tighter throughout the day. Nothing major with a used chain.
Never gets loose when cold only tighter, but maybe that's just me.

I have to live by the laws of physics now since I don't have a reality stone at my command to alter materials expansion rate... so I don't know how it works for everyone else.

Yes, he burned up his bar. Couple a dull chain, improper oiling and leaning on the saw, it can happen fast. He needs to push in the pin, turn the Oiler up to max, buy a new bar and chain, tension it properly, sharpen it when needed, and stop leaning on the saw to compensate. This is 100% operator error.

 

[Trdoldtreecutter]

What do I do for a living? For the last 38 years I’ve cut and forwarded saw logs and pulp. Don’t believe me? R.I. woods operator # 21-31, arborist lic # 403, Ct supervising harvester lic # 001052. Unlike you I don’t hide behind a screen name and sling BS as sport.

Well, you wouldn’t be the first guy I’ve seen running equipment that was an expert with anything to do with a chainsaw lol

 

[Leeroy]

The last thing I did yesterday was spend 1/2 an hour cutting and bucking a dead white oak in the landing, then I trimmed the log pile. Without any adjustment my chain is at least as tight, if not tighter this morning than when my saw went in the truck box yesterday afternoon. when was the bar and chain hotter, when I put the saw away or this morning?

Jhenderson: you need to get your saw pinched, then stretch that chain out!

 

[IMSkywalker]

if you are comfortable with your dealer you bought the saw from, take all this information you have collected and pay them a visit. If dealer is sharp then im sure you'll get to the bottom of things.

Could be as simple as a defective bar from the factory they'll swap out....

Thanks for for the reply. Good advice and I hope that's the case. I had to buy from a dealer 65 miles away, saws were already scarce due to pandemic, after the storm you couldn't buy a saw within 100 miles of where I live. I hated buying from another dealer but my dealer had no idea if, when or what he could get from Stihl. Oddly, when I showed them the issue, my local Stihl dealer stated they could not honor a bar warranty if they did not setup the saw. Doesn't seem right. I plan to just take it back to the dealer where purchased. I hope they are sharp with Stihl products. However, they sell about 12 brands of products - John Deere, Kubota, Frontier, Honda, Cub Cadet...............

 

[IMSkywalker]

You need to punch in the limiting pin like it explains in the owners manual so you can turn the Oiler up to max. This is more EPA ********, they’d rather you burn up your bar than splatter a little bar oil on the forest ground

I explained earlier how to do this. The red arrow points to the limiting pin that needs to be knocked in. You’ll see a dramatic increase in oil output once you do this. You’re running it at half output in hardwood, not good.

Then go get a new bar and chain and keep it tensioned properly and sharpened properly.


View attachment 862499
View attachment 862500

I see, the pin stop is due to EPA regs. I agree with pressing in end stop pin & increasing the Oilmatic setting. Just for reference, my 026 Pro has the same adjustment and it is still on "E" with NO issues. Thanks for the diagram.

 

[Jhenderson]

Well, you wouldn’t be the first guy I’ve seen running equipment that was an expert with anything to do with a chainsaw lol

And you’re not 1st Internet blowhard I’ve seen hiding behind a screen name while giving out bad advic, trying to cover up a lack of basic knowledge with unsubstantiated claims of experience.

 

[Westboastfaller]

I've always thought the "loosen chain or bend crank" thing was a lot of hooey.

Oh yeah, Stihl work shop says this below in quotations. What other things have manufacturers said over the yrs? ..'wait 10 min before refuelling a hot saw'..'Only use our petroleum products with our saws for warrantee, to be purchased at the time of the saw ' ..'use our brand oil at 50:1 or other brands at ××:1 (much higher concentration) warning signs not to drink petroleum products.
just a few that came to mind.
Let's break this down what they are saying below:


"Important:
Since the chain contracts slightly when it cools, it should never be tensioned or
changed while warm.
This could lead to serious problems with the guide bar or crankshaft.
It is advisable to relax the chain slightly after use, particularly in frosty weather"
_____________________________
So they are saying if you have a chain throw and put your chain on traditionally then you must wait until it is cold,
So if it's advisable to relax your chain after use then that also includes every time you will be off the/that particular saw for longer than 10-15 min then. Haha
I am sure nobody does that.
My question is why not if they do it at the end of any given work day? (Come and get the memo.)
Then let's wait 10min between refuelling also?
IDK, they sure didn't pay me $107 per hour on the coast to study & conform to any of that crap.

 

[Trdoldtreecutter]

And you’re not 1st Internet blowhard I’ve seen hiding behind a screen name while giving out bad advic, trying to cover up a lack of basic knowledge with unsubstantiated claims of experience.

Ya, you win. I really just joined with some chainsaw mill questions. Not sure what possessed me to give advice when there’s obviously experts like yourself on here. Adios

 

[Short timer]

Oh yeah, Stihl work shop says this below in quotations. What other things have manufacturers said over the yrs? ..'wait 10 min before refuelling a hot saw'..'Only use our petroleum products with our saws for warrantee, to be purchased at the time of the saw ' ..'use our brand oil at 50:1 or other brands at ××:1 (much higher concentration) warning signs not to drink petroleum products.
just a few that came to mind.
Let's break this down what they are saying below:


"Important:
Since the chain contracts slightly when it cools, it should never be tensioned or
changed while warm.
This could lead to serious problems with the guide bar or crankshaft.
It is advisable to relax the chain slightly after use, particularly in frosty weather"
_____________________________
So they are saying if you have a chain throw and put your chain on traditionally then you must wait until it is cold,
So if it's advisable to relax your chain after use then that also includes every time you will be off the/that particular saw for longer than 10-15 min then. Haha
I am sure nobody does that.
My question is why not if they do it at the end of any given work day? (Come and get the memo.)
Then let's wait 10min between refuelling also?
IDK, they sure didn't pay me $107 per hour on the coast to study & conform to any of that crap.

To be clear, you’re saying the laws of physics are wrong and Stihl engineering is wrong that a hot chain expands and a cold chain contracts?

 

[Short timer]

Just for reference, my 026 Pro has the same adjustment and it is still on "E" with NO issues. Thanks for the diagram.

Your 026 doesn’t have the same adjustment, you have unrestricted travel through the full range of adjustment. Your 661 is being prevented from going any higher than half output. You are thinking the oiler isn’t working properly, but you‘re not turning it up to where it can give you the output you’re looking for.

Not enough oil? Adjust it so it oils more. Pin knocked in and adjustment full clockwise will give you about 1:1 fuel to bar oil consumption rate. Monitor it though so you’re not running out of oil before fuel.

 

[Short timer]

Just for reference, my 026 Pro has the same adjustment and it is still on "E" with NO issues.

Also to clarify, I think you’re under the assumption that the “E” spot is some special setting, it’s not. The pump still operates the same throughout all the range, it just puts out more oil the further clockwise you turn the control bolt. The “E” is nothing more than the most economical spot for whatever bar they designed that particular saw around. A “medium” output. If you think that you could throw any length bar on the 661, leave the setting on “E” and it will somehow automatically oil it properly, you would be wrong.

Stihl oilers are pathetically stingy now a days. I crank all my saws to max and don’t ever touch it. Like I said, it’s treehuggers that don’t want you splattering any bar oil on the forest ground.

 

[Bwildered]

Well, you wouldn’t be the first guy I’ve seen running equipment that was an expert with anything to do with a chainsaw lol

I've seen & heard some pretty amazing stuff from people with 50 years experience in logging, one the best ones was, you won't get a spark from the negative terminal when using jumper leads on a battery

 

[Westboastfaller]

To be clear, you’re saying the laws of physics are wrong and Stihl engineering is wrong that a hot chain expands and a cold chain contracts?

There you are, I was just going to quote you from last night but you took your post down.
Why would you do that? You were saying you had chains tighten up that got to hot. You contributed it to not enough oil.

In regards to chains tightening up.
My ported Walkerized 357xpw with 20" bar was a hungry little saw. It was aggressively filed always.if the chain was slightly tight whilst making a few 20" bucks then it would become real real tight. I would open the oil cap and splash some on the face of the bar but after once or twice of doing that and still having a few more cuts then I would just end up backing it off..which would contribute to another problem with chips getting under the driver's easier If I was holding the powerhead to close to the log.
Anyway, it's well known that saws will do that (especially small saws) so... then that would only point to the bar getting heat soaked and expanding. Would it not?
As said, you contributed it to lack of oil to be the cause in you post.
But what is going on there in your words?

 

[Short timer]

There you are, I was just going to quote you from last night but you took your post down.
Why would you do that? You were saying you had chains tighter up that got to hot. You contributed it to not enough oil.

In regards to chains tightening up.
My ported Walkerized 357xpw with 20" bar was a hungry little saw. It was aggressively filed always.if the chain was slightly tight whilst making a few 20" bucks then it would become real real tight. I would open the oil cap and splash some on the face of the bar but after once or twice of doing that and still having a few more cuts then I would just end up backing it off..which would contribute to another problem with chips getting under the driver's easier If I was holding the powerhead to close to the log.
Anyway, it's well known that saws will do that (especially small saws) so... then that would only point to the bar getting heat soaked and expanding. Would it not?
As said, contributed it to lack of oil to be the cause in you post.
But what is going on there in your words?

So that’s a yes, you’re arguing with the laws of physics and stihl engineering?

As far as that post, yes it’s happened to me one time from lack of lubrication, not because the chain contracted when it got hot, like you’re attempting to say, but because the bar overheated and expanded more than the chain did.

 

[Short timer]

I’ll say this. If you tension your chain cold, go cut, never touch the adjustment, the only way your chain will be loose the next day “I have to tension the chain the next day when sharpening” as you stated, is if something moved or the chain stretched. A chain that cooled down isn’t going to cause it to expand, Period, it ain’t happening.

Anything else is ********.

The problem arises when people tension their chains hot, then it cools down, contracts and can cause unnecessary stress on the crank and bearings. This is what stihl is saying.

 

[Fatherwheels]

If that’s the case why do people back off the chain tension after running to not put stress on the crank?

Exactly what I do, I leave chain loose, then tighten before starting again.
Seen people put saws down after work, temperature drops below freezing at night,
engine couldn’t budge the chain the next morning, bearings flat spotted, then they wonder
why their saw gave up with such low hours.
Some people are better away from tools that need adjusted as required.

 

[Westboastfaller]

Anyway, it's well known that saws will do that (especially small saws) so... then that would only point to the bar getting heat soaked and expanding. Would it not?

yes it’s happened to me one time from lack of lubrication, not because the chain contracted when it got hot, like you’re attempting to say, but because the bar overheated and expanded

It's only when you aren't man enough to sit at the big boy table, is it when 'one, feels the need to play little games.
...and with you, that would be every thread I've seen you on.

No further question at this time.

 

[Fatherwheels]

So that’s a yes, you’re arguing with the laws of physics and stihl engineering?

As far as that post, yes it’s happened to me one time from lack of lubrication, not because the chain contracted when it got hot, like you’re attempting to say, but because the bar overheated and expanded more than the chain did.

Of course chains tighten up when they are dragged along a dry rail, tighten as in putting
the brakes on the car and driving at the same time, the metal links also swell in the bar groove
causing more stretching of the chain as the engine tries to pull it around,
the rails also expand, in both directions further clamping the bar.
A well lubricated sharp chain that is pre stretched will get shorter after you stop cutting,
as it cools from working temperature, a stretched scalded dry chain won’t shrink back
to normal after the abuse it suffered, so if that’s how your chain hangs when you park your
saw, leave it parked.

 

[Short timer]

It's only when you aren't man enough to sit at the big boy table, is it when 'one, feels the need to play little games.
...and with you, that would be every thread I've seen you on.

No further question at this time.

Are you drunk again?

What you said is flat out wrong. A properly lubricated bar and chain, the chain will become looser when running, not tighter.