18" Stihl MS 250 -blade or chain problem?-

[Daulton Ruff]

Howdy!

I have a "newish" two year old Stihl MS250. It seems a whole lot more persnickety than the old Stihl l chainsaw I owned. I've already had to change the fuel tank filter, spark plug, and you would think this thing would be easier to start. Hope chainsaw mfgs don't go the way of modern refrigerators.

Here's my problem;

Something happened to either my blade or the Oregon chain, two of them, that I am using. I am leaning to believe something I can't see is wrong with the blade because the chain seems to bind in the channel, (which I cleaned). Not the tip of the blade but nearer the back. I have managed to do some cutting but my saw isn't performing the way it should. I have noticed that on both blades there are segments that look like the front edge, (that runs in the channel) is damaged, like it has been impacted some way. I've tried to file those edges smooth but that is difficult, but it seems like that needs to be done as the blade still will not slide inside that channel on the newest blade as well as the older blade smoothly. I didn't have this problem initially.

I changed to the Oregon blade because it would cut. I tossed the Stihl blade after some really frustrating days with their blade that would not cut butter.

Thanks for your time and for your suggestions.

[peatff]

It's called the bar or guide bar all the blade references are confusing, the bar doesn't cut anything so the Stihl one which would not cut butter was probably not the problem. Get a new bar and matching chain from the same manufacturer and start from scratch.

[bmp01]

Sorry I'm a bit confused too. ... but I get that the chain is binding in the guide bar. Two things spring to mind (but there are going to be many others).

1) have you got a chain that is compatible with the guide bar ie correct thickness of chain drive link for the bar groove width?

2) are the chain drive links damaged on their leading edge causing a burr over sides of the drive links.

 

HTH, sorry if I've got the wrong end of the stick.

 

[Rough Hewn]

Howdy!
I have a "newish" two year old Stihl MS250. It seems a whole lot more persnickety than the old Stihl l chainsaw I owned. I've already had to change the fuel tank filter, spark plug, and you would think this thing would be easier to start. Hope chainsaw mfgs don't go the way of modern refrigerators.
Here's my problem;
Something happened to either my blade or the Oregon chain, two of them, that I am using. I am leaning to believe something I can't see is wrong with the blade because the chain seems to bind in the channel, (which I cleaned). Not the tip of the blade but nearer the back. I have managed to do some cutting but my saw isn't performing the way it should. I have noticed that on both blades there are segments that look like the front edge, (that runs in the channel) is damaged, like it has been impacted some way. I've tried to file those edges smooth but that is difficult, but it seems like that needs to be done as the blade still will not slide inside that channel on the newest blade as well as the older blade smoothly. I didn't have this problem initially.
I changed to the Oregon blade because it would cut. I tossed the Stihl blade after some really frustrating days with their blade that would not cut butter.
Thanks for your time and for your suggestions.

Remove the bar, chain and drive sprocket.
Buy new ones.
Look after them.
[emoji106]

[Daulton Ruff]

Thanks for your replies. I just spent an hour out there carefully using a cut off blade 😛 cleaning the burrs off of the lower guide part of the chain, cleaning with a wire brush, and looking for any lateral damage to any links. I didn't see any damaged links but I was able to make the chain slide in the channel better.

I also examined very carefully, which I did when I purchased the chain, to make sure I was replacing the blade with the same specifications the guide bar has stamped on it, and is the same as the other chains I have. I did learn that the Stihl blade had a different chisel shape which probably made the difference in the cut I was complaining about. My Oregon blade is a lot more aggressive, and makes me a lot happier.

What is funny to me is that the burrs that I smoothed off were not on the leading edge but were on the back and only in certain areas. I wonder if the chain was slightly damaged when it comes off of the bar, which it does if I allow it to get sloppy.. I know, don't do that. I still can't figure out how it would happen that the little burrs would be on the back of the bottom of the blade. In a couple of places on the chain, in spans of maybe an inch or two.

As far as buying a new bar, or a new chain, the saw is practically new. I've used it only a few times on trees around my house. I see no damage, or wear to the bar, and the chain hadn't even needed to be sharpened yet. It's still sharp.

Anyway, at this point, I believe my next use of the saw will be my test. Sorry for the confusing descriptions. I really struggled not to use the word thing-a-ma-jig, or dumawhatchie.

 

[peatff]

4 minutes ago, Daulton Ruff said:

What is funny to me is that the burrs that I smoothed off were not on the leading edge but were on the back and only in certain areas.

 

Had you fitted the chain backwards at some point ?

[bmp01]

26 minutes ago, Daulton Ruff said:

What is funny to me is that the burrs that I smoothed off were not on the leading edge but were on the back and only in certain areas.

I've seen drive links damaged from new.

Also worth noting the drive sprocket on the chainsaw is applying drive to the chain on the back of each drive link, not the front (front drive link damage is often chain and bar misalignment). Set saw up on the bench without the side cover, turn the drive sprocket and watch ...

You are 100 % sure you have the right 'chain pitch', examples 3/8" LP or 0.325 or 3/8" Std ... ? Chain pitch must match the drive sprocket, guide bar must match drive sprocket (and chain ).

[Daulton Ruff]

Well, I've checked to make sure my chain pitch, etc. for both chains I bought and used are the same as are on the blade, but the other information about the drive sprocket is interesting and I will check that as soon as I have time, and before I go out to cut any wood. What would you think would cause a sprocket to damage  links in only a few places? 

I didn't check the chains before I put them on so I have no idea if they may have been rough when I purchased them, but that is also something I will keep in mind. Good input.

Thank you for that.

[Daulton Ruff]

To Peatff; Yes, I'm sure that as I have put the chain on, then figured out, that ain't gonna work backwards, probably at least a couple of times,  but I've never run the saw with it that way, I don't think or remember that I did.  Would that cause the damage I've described?

[Stubby]

Chain with cutters on . Guide bar is what the chain runs in . Blade is on my knife .  Stihl chains have drive links that are . 063 "  wide  other manufactures use chains that are .058" wide ( on that size saw )  . If you have a Stihl chain in the narrower size guide bar it will pinch . Conversely if you have an .058" wide chain in a Stihl bar it will rock .  Check you have all the comparable drive train as others have said .