Odd Chain Behavior with Echo CS-271T

[mh9162013]

I've been tinkering with my Echo CS-271T that I got for $80 a few months ago. It works, but I can't say it's safe to operate.

From the very beginning I noticed the chain catcher needed replacing and that I needed to adjust the chain tension. But after messing around with it a few times, I'm beginning to wonder if there are more serious problems or issues.

Right now it has a 14" Oregon bar and chain. What's odd is that I can never get a consistent tension on the chain as it will randomly get too loose. I tighten it up without issue, but after moving the chain with just my fingers, the chain gets loose again. As far as I can tell there's nothing wrong with the chain tensioner. And the most odd thing is that the loose chain is inconsistent. What I mean is that one second the chain seems properly tensioned. After moving the chain around a few times, the chain is clearly too lose. Move it around a few times again, and it's under tension again. I do not observe the bar (or anything else) moving at all when I do this.

I know the metal plate guards that actually sandwich the bar and hold it in place need replacing as they have tears in them. But could the chain and/or bar be defective? I'm no chainsaw expert, but the chain and bar appear just fine. I'm wondering if there's a more serious problem with the chainsaw (or bar and chain) because:

1) The bar doesn't get oiled even though the oiler is clearly working (I tested it by running the CS-271T without the bar and chain and oil was oozing out of the slot in the powerhead).
2) The chain catch has been sheared (hence the need for a replacement) and some plastic on the sprocket cover (the part that holds the chain brake and chain tensioner assembly) that surround the clutch is missing as if it has been torn away from a loose chain.

So there seems to be missing plastic (that was violently torn off) from this chainsaw for a reason, but I don't know what that reason is. Perhaps the bar and chain are defective or otherwise need replacing? Or maybe there's something else at issue with the powerhead itself?

Any tips would be appreciated. I consider this chainsaw as "grounded" and will no longer run it with the bar and chain on it until I figure out what's wrong with it (or what I'm doing wrong).

 

[rupedoggy]

Take the bar and chain off the saw. Look at the drive links for any damage. Find out what pitch and gauge the chain is. Now to the bar. Check the grove to make sure it is clean and not worn. Is it consistent with the gauge (.050, .058 or .063)? Are the rail tops square and not worn on one side more that the other? Is the sprocket tip in good shape and the same pitch as the chain (pico, .325 or 3/8)? If it does not match this would be the problem. Now look at the drive sprocket. Is it the same pitch as the chain? Is it worn or grooved? If you check all this you will probably find the problem. Mike

 

[Deleted member 149229]

If the chain on the saw is the chain that did the damage then the drive links on the chain could be mangled and need repaired, and the bad drive links could have caused the groove in the bar to also become oversized.

 

[mh9162013]

Thanks for the great tips. I'll take a closer look.

 

[stubnail67]

It takes a a041 mount 3/8s lopro sounds like you have the wrong bar and chain ... hope it did not tear up the spur.....its way better with a 12 inch bar and chain a041 45links ....i have purchased saws that do this and usually they have the wrong bar setup on them.... if you have run it with the wrong set up you most like will need a new spur.... take the bar and chain off and tak a pic of it and the chain for us and the spur/sprocket...

 

[Mauser]

I know nothing about your particular saw, but your problems are very similar to what I had with a Poulan 2900. On that saw, the bottom four bolts that secured the motor into the plastic case vibrated loose and allowed the whole motor to move around slightly. As it twisted to the left the chain would loose, and tighten as it twisted back. On top of that, those changes in the motor position would cause the sprocket to change alignment with the bar, and I had several thrown chains with damaged drive links. This was all with the stock bar and chain.

 

[mh9162013]

Here are some pics from this morning:

 

[mh9162013]

I know nothing about your particular saw, but your problems are very similar to what I had with a Poulan 2900. On that saw, the bottom four bolts that secured the motor into the plastic case vibrated loose and allowed the whole motor to move around slightly. As it twisted to the left the chain would loose, and tighten as it twisted back. On top of that, those changes in the motor position would cause the sprocket to change alignment with the bar, and I had several thrown chains with damaged drive links. This was all with the stock bar and chain.

Thanks for your insight, but I sure hope that's not the case here.

From some brief research on Oregon's website, it looks like the bar I'm using is not officially compatible with the CS-271T. Can anyone else confirm my conclusion?

 

[ericm979]

That engine sprocket looks very worn. Try a new one and a new chain.

Bailey's has an extensive bar selector. Might be worth using to cross check the Oregon info.

 

[mh9162013]

That engine sprocket looks very worn. Try a new one and a new chain.

Bailey's has an extensive bar selector. Might be worth using to cross check the Oregon info.

How does it look worn? I only ask for future reference. My first thought was that the sprocket looked great! In other words: what should the sprocket look like if it were in good shape?

EDIT: I just used Bailey's bar selector. Guess which Oregon bar didn't come up for the CS-271T? Hint: Mine. It finds me "140DGEA041," but not the "#140SDEA041," which is what I'm using.

 

[stubnail67]

Sprocket is worn. the chain guards are shot... i see oil and thats the right bar....you have to keep the chain tight when they are new ... if not it will throw it and tear **** up....it looks like it tore stuff up.....odds are the chain is shot also.... the bar looks ok from pics....and its the right one ... mount wise.... i would run a 12 inch but depends on what your cutting....hope this helps.

 

[stubnail67]

this is the combo it calls for on that saw...

https://www.oregonproducts.com/en/guide-bar-and-chain-combo,-12"/p/105698

 

[mh9162013]

Sprocket is worn. the chain guards are shot... i see oil and thats the right bar....you have to keep the chain tight when they are new ... if not it will throw it and tear **** up....it looks like it tore stuff up.....odds are the chain is shot also.... the bar looks ok from pics....and its the right one ... mount wise.... i would run a 12 inch but depends on what your cutting....hope this helps.

If it's the right bar, is no one recommending it because they think a 12" bar is best on the CS-271T instead of a 14"?

Based on what you've seen, you believe I need a new sprocket? How can you tell it's worn? I would like to learn how to identify a worn sprocket.

 

[ericm979]

Here's pics of a new spur sprocket:

No grooves from the chain at all.

 

[mh9162013]

Wow, that's good to know, thanks. Those grooves looked so even, I thought there are supposed to be there!.

 

[Mauser]

How does it look worn? I only ask for future reference. My first thought was that the sprocket looked great! In other words: what should the sprocket look like if it were in good shape?

EDIT: I just used Bailey's bar selector. Guess which Oregon bar didn't come up for the CS-271T? Hint: Mine. It finds me "140DGEA041," but not the "#140SDEA041," which is what I'm using.

Those two numbers are virtually the same bar - according to the Oregon catalog, the only difference is that the "DG" bar has a hole to mount a tip guard, and the "SD" bar does not. Both bars are for a 3/8" low profile 91 chain (that is what the "E" means).

The pictures you posted of your chain show it is the correct one for that bar (assuming that 52 links is right for that saw - my Homelite that uses a 14" bar uses an S53 chain, but that is not common). The drive links in the pictures look good to me, but that sprocket is BAD Bad bad - Terribly worn. Best advice when you have a sprocket that badly worn is to expect the chain to be damaged too, so you should consider getting a new chain along with the new sprocket. I am a cheap bastard, so I would hate to ditch that chain myself, but if the drive links are worn or damaged, it can ruin a new sprocket quicker than you would like. If you do not want to replace the chain, CAREFULLY inspect every drive link for damage.

Now a bigger issue for you may be determining if the bar is bad, ESPECIALLY after the symptoms you describe. Try to wiggle that chain side-to-side on the bar - if you get any more than very MINIMAL flop, then I would suggest you really need to replace all three items, new bar, chain AND sprocket.

And just for kicks, while you have that bar off the machine, grab the clutch drum and try to move it forward or back - ANY movement at all is a big problem, and you will need to figure that out before mounting any new parts.

 

[mh9162013]

Thank you for the great input, Mauser. I'll definitely take what you say into consideration. Like you, I'm cheap, so I'd like to reuse the bar and chain, but not if it jeopardizes my safety. Also, I think 14" is a bit too much for a saw of this size. The whole point of a top handle chainsaw is for low weight and size. But if I'm going to get a new bar and chain, I may look at a 10 incher.

Thanks again to everyone for the information and assistance!

 

[Mauser]

Although I do not have personal experience with your saw, I would think that it should be just fine with a 14" bar. I compare it to the Homelite XL-2 and Super-2; the XL-2 has about the same size motor (26.2cc), and it came with either a 12" or 14" bar. The Super-2 is virtually identical with the XL-2, but has a slightly larger motor (31.1cc), and it came with either a 14" or 16". The Super-2 was my first saw, and I bought it with a 14" bar, but since it was my only saw for close to 10 years and I was doing a lot of tree thinning and firewood cutting, I ran it with a 16" bar for a long time, and it always pulled real strong in ash, elm, bois d'arc, hackberry, and oak. I eventually acquired other saws for the bigger work and went back to the 14" on the little Homelite.

I have never owned a saw with a bar shorter than 14", but I imagine a 10" would be just too stubby for my taste. I use my Homelite for a lot of cleanup on old piñon pine and juniper trees where the bottom 5' of the trees are just choked with dead branches - the little top handle saw with a 14" bar helps me reach what I need to do while I begin to open up the mess. I might get by with a 12", but I do not think I could get much done with something shorter.

I don't really have a need for a chainsaw to cut chop sticks.

 

[Colt Marlington]

Found a 355T for $80 at a pawn shop. But it was beat to heck with a missing top cover, cracked starter cover, and a broken handlebar.
I was still tempted because I wanted the open muffler for my 361P. But I left it there.

The 12" bar is a good match for my 2511T, which has similar power to the 271T.
And my XL2 Automatic also has a 12" bar which seems about right, although a taller profile.
I had a new 10" Echo bar and chain that I tried on the 2511T when I got a burr on a drive link on the 12" chain, but don't like the smaller bar on that saw. Luckily, the 10" b&c should still serve as a good backup for my PPT-2620 pole saw.

 

[jrs_diesel]

That is one worn out sprocket. For reference, here's a page from the manual that talks about sprocket wear:

[photo=medium]5576[/photo]