New Stihl MS261 - uneven chain tension

[Chevboy0167]

Is it just me or.......??? From post #10

 

[PV Hiker]

Is it just me or.......??? From post #10

I saw that also and can't seem to figure what that is??

 

[Patrick1903]

I did not reverse it as I feel like my other experiment already settled it's the sprocket. I uninstalled the sprocket, kept the drum in the same orientation, and reinstalled the sprocket in a different orientation.

To put it more simply, I marked the sprocket location where loose (a notch with a sharpie at 5 oclock), kept drum in same location (notched at 5 also) and then reinstalled sprocket at like 8 oclock orientation based on notch. Chain was loose at 5 oclock again. Did the same thing and put sprocket at like 12 noon. Loose spot is still with sprocket at 5 oclock. I feel that shows it's the sprocket specifically.

Understood that. I was wondering if the thickness of the sprocket teeth were uneven if you oriented the sprocket the opposite direction. Ie if each tooth is like a triangle, and depending on the orientation of the sprocket your drive link will be pulled by one side of the sprocket tooth. Perhaps the other sides I’d the tooth are less uneven, or less thing, or whatever was causing the issue. In other words, the sprocket to some degree is actually like having two sprockets because each tooth has 2 sides. So was wondering if both sides had been checked or if it made a difference at all. But sounds like your replacement will get you to what you need.

 

[Amin_1992]

I saw that also and can't seem to figure what that is??

Geez I didnt notice that either til now... no clue what that is? I'll take a gander. Just bought the chain last week and barely put half a tank through it so far.

Understood that. I was wondering if the thickness of the sprocket teeth were uneven if you oriented the sprocket the opposite direction. Ie if each tooth is like a triangle, and depending on the orientation of the sprocket your drive link will be pulled by one side of the sprocket tooth. Perhaps the other sides I’d the tooth are less uneven, or less thing, or whatever was causing the issue. In other words, the sprocket to some degree is actually like having two sprockets because each tooth has 2 sides. So was wondering if both sides had been checked or if it made a difference at all. But sounds like your replacement will get you to what you need.

Ah i see what youre saying. I am new to rim sprockets and didnt think of that until you explained it. So these are truly reversible?

 

[Amin_1992]

Got home and checked out every link of the chain - nothing chewed up like in the pic! My only thought is the flash of my phone camera hit some gunk or oily sawdust and made the illusion of damage? Weird!

 

[lone wolf]

Got home and checked out every link of the chain - nothing chewed up like in the pic! My only thought is the flash of my phone camera hit some gunk or oily sawdust and made the illusion of damage? Weird!

Is the chain new dont look new.

 

[Amin_1992]

It was brand new last week. Put half a tank of gas through it bucking red oak. Tried an updated pic. Dirty but new.

 

[IntegrityCarpentry]

Are there some Oregon sprockets that are generic? Do the genuine ones say power mate or oregon or is it a mixture. Found more funky ones today…I just need some good sprockets, am I going to have to order them in dozens and sort them lol? And only from larger dealers?

 

[HarleyT]

Take it off and lay it on the table, and take a good pic. Same with the rim.

 

[REJ2]

Are there some Oregon sprockets that are generic? Do the genuine ones say power mate or oregon or is it a mixture. Found more funky ones today…I just need some good sprockets, am I going to have to order them in dozens and sort them lol? And only from larger dealers?

This link is from a saw shop in Iowa, they are not my only source but all their prices include shipping. Rims, sprockets with or without rims, combos can be found with a little searching. Some offerings even compatible with Stihl. They used to have some of the best prices on pre made loops of Oregon saw chain.

https://loggerchain.net/

 

[Patrick1903]

Geez I didnt notice that either til now... no clue what that is? I'll take a gander. Just bought the chain last week and barely put half a tank through it so far.


Ah i see what youre saying. I am new to rim sprockets and didnt think of that until you explained it. So these are truly reversible?

Yes.

 

[IntegrityCarpentry]

This link is from a saw shop in Iowa, they are not my only source but all their prices include shipping. Rims, sprockets with or without rims, combos can be found with a little searching. Some offerings even compatible with Stihl. They used to have some of the best prices on pre made loops of Oregon saw chain.

https://loggerchain.net/

Thank you so much. They were my first place to order chains years ago. I didn’t know they had sprockets. Thank you. I will check them out.

 

[Amin_1992]

Hey all, wanted to reply back with a final update. Found a dealer with 2 sprockets in stock. Installed one of them and the issue is gone now! When looking, there is a high and low spot as evident by a change in chain tension, but it's almost unnoticeable compared to how it was with the original sprocket - I don't think I'd even notice this difference had it came this way. As many of you pointed out, no sprocket is 100% perfect, which I know now.

Even when holding the two sprockets together against each other, I can see on the original it is not perfectly centered - and the high/low point matched up with the notch I marked that corresponded to high/low chain tension.

Case closed! Crazy a sprocket straight from factory was that bad. Funny enough, the two sprockets I got from a dealer must have been sitting around a while. Surface rust on them and one looks to be strangely casted as it has a big line in the metal. But nonetheless, they are working better than the original.

Thanks all for your help. I hope this helps someone else in the future.

 

[IntegrityCarpentry]

Hey all, wanted to reply back with a final update. Found a dealer with 2 sprockets in stock. Installed one of them and the issue is gone now! When looking, there is a high and low spot as evident by a change in chain tension, but it's almost unnoticeable compared to how it was with the original sprocket - I don't think I'd even notice this difference had it came this way. As many of you pointed out, no sprocket is 100% perfect, which I know now.

Even when holding the two sprockets together against each other, I can see on the original it is not perfectly centered - and the high/low point matched up with the notch I marked that corresponded to high/low chain tension.

Case closed! Crazy a sprocket straight from factory was that bad. Funny enough, the two sprockets I got from a dealer must have been sitting around a while. Surface rust on them and one looks to be strangely casted as it has a big line in the metal. But nonetheless, they are working better than the original.

Thanks all for your help. I hope this helps someone else in the future.

This is sad, and until recently I didn’t even realize it could be a problem. Glad your back in the Saddle again. Some of us, including myself need to get half a stash of decent sprockets

 

[Amin_1992]

This is sad, and until recently I didn’t even realize it could be a problem. Glad your back in the Saddle again. Some of us, including myself need to get half a stash of decent sprockets

Ya not the best way to start off with a brand new Stihl but is what it is.

Hey I've got a barely used sprocket for you, $100 and it's yours

 

[REJ2]

Ya not the best way to start off with a brand new Stihl but is what it is.

Hey I've got a barely used sprocket for you, $100 and it's yours

I have been able to purchase the two common Oregon sprockets that fit my large huskys and my small echo and small husky on ebay for about $5.25 -$6.50 each if i buy a ten pack. Ya gotta be careful though, lot of claims the part is Oregon but plenty of knock offs with misleading wording. There are however legit Oregon made rims if you search and look carefully.

 

[Treeman2021]

Maybe i have missed it but what brand chain are you using? and if you started off wih an OEM Stihl how was the cm261 cutting? i think all chains go through slight changes, but what counts is the quality of cuting.