260 sprocket trouble

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Like The Woods!

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Joined
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Location
Middle of the Great State of Maine
Hapyp Bird Folks!
I am a long time lurker, as well as being a long time chainsaw user. Part time from the 60's till present. That being said...I don't know much....

Have a MS260 Pro. Finally changed to a adjustable carb. Was running a hair under 14k, and running good. Made a few test cuts in softwood, and it was a major improvement. I was happy...till...I tried it on a 2' dried beech log. Made a couple of cuts...all was well. Then in the middle of the next cut, the chain just stopped moving, and smoke rising from under the clutch cover. The gear on the clutch drum and the rim sprocket itself were rounded off big time. They had both stripped to almost round. I have another drum/sprocket. The saw seems to be free turning. Clutch looks ok to me.

Before putting on the new parts, I thought I would seek some advise, as to what possibly caused it, so I don't ruin the new parts also. Thanks, Al

I have Bailey's a 20" narrow kerf bar and .325 narrow kerf chain (20nk) on it at the moment. I, (with tractor), am digging small to 20" trees, shaking the dirt off as much as I can, and cutting the "stump" off. So I am cutting a lot of dirt. Making piles, and have a whole tree chipper coming after the new year.

But I digress...The saw was cleaned and the sproket was not overly worn. Any thoughts as to why I smoked the sprocket, and drum gear?
 
Like The Woods! said:
Hapyp Bird Folks!
I am a long time lurker, as well as being a long time chainsaw user. Part time from the 60's till present. That being said...I don't know much....

Have a MS260 Pro. Finally changed to a adjustable carb. Was running a hair under 14k, and running good. Made a few test cuts in softwood, and it was a major improvement. I was happy...till...I tried it on a 2' dried beech log. Made a couple of cuts...all was well. Then in the middle of the next cut, the chain just stopped moving, and smoke rising from under the clutch cover. The gear on the clutch drum and the rim sprocket itself were rounded off big time. They had both stripped to almost round. I have another drum/sprocket. The saw seems to be free turning. Clutch looks ok to me.

Before putting on the new parts, I thought I would seek some advise, as to what possibly caused it, so I don't ruin the new parts also. Thanks, Al

I have Bailey's a 20" narrow kerf bar and .325 narrow kerf chain (20nk) on it at the moment. I, (with tractor), am digging small to 20" trees, shaking the dirt off as much as I can, and cutting the "stump" off. So I am cutting a lot of dirt. Making piles, and have a whole tree chipper coming after the new year.

But I digress...The saw was cleaned and the sproket was not overly worn. Any thoughts as to why I smoked the sprocket, and drum gear?
If you'v changed your rim sprocket and used something other then stihl brand the fit will be to loose and may slip.
 
Howdy Like The Woods!,

Man you tore that one up pretty good. Was the bar sprocket seized up or binding? If so I would suspect that. If not I would hazzard a guess and say not enough oil/lube + big dry beech + maybe some dirt/debree and maybe the chain was being pinched or binding in the cut. If you add all those up it might do it.

Was that bar chain ever pinched or chain thrown? I would clean and inspect the chain pay attention to the underside, look and feel for bur or damaged drivers. That could bind your chain in the bar. Also clean and inspect your bar. Look for pinched rails or damage inside the groove. Make sure you can sping the sprocket easy. Then just hold the bar and put the chain on it and pull it around and see if its dragging anywhere, top and bottom.

14K on a 260, I dont know enough about them but I would check that I'm not exceeding max rpm. Thats sounds pretty fast, maybe thats were its supposed to be?

Put her all back together and make sure you can free hand that chain around the bar. Good luck.

v/r

Mike
 
Sugarbush and Fish,

Good eyes fella's. I would not have though of that. I'm glad there are smart/well seasoned folks on here. You guys have a Happy Thanksgiving.

Like The Woods!,

Were those after market parts?


v/r

Mike
 
Don't feel bad, I have been told never to sing again or there will be "contract" put out on my life, I have been asked not dance and advised not to seek employment in the adult film industry. You got off light by having your photo skills criticized. The Stihl version of the small spline is unique to Stihl. I suggest swapping the drum to Oregon or buying all of your parts from the Stihl dealer, don't mix and match
 
Thanks

"If you'v changed your rim sprocket and used something other then stihl brand the fit will be to loose and may slip."

The sprocket and chain was not stihl. They were however new. Have been running them for a while. The extra drum to be installed is not stihl either. I guess I better stick with OEM.

"Man you tore that one up pretty good. Was the bar sprocket seized up or binding? If so I would suspect that. If not I would hazzard a guess and say not enough oil/lube + big dry beech + maybe some dirt/debree and maybe the chain was being pinched or binding in the cut. If you add all those up it might do it."

A couple of weeks ago my son slipped in some Stihl bar oil, unbeknown to me. I immediately noticed the difference. The bar/chain was showing a lot of oil. It converted me to using Stihl, instead of Wally World.

I have always had the oil adjustment open fully. Yesterday I turned it to half.
So maybe it was a combination of 'stuff" that happened to cause this.

Appreciate your help!
 
Like The Woods!, In the last few weeks, Bought a Stilh Drum kit
It came with drum,sprocket,washer and the clip for $18.50 plus tax.
Not that helps you, but thought you mite like to know the price
 
Like The Woods!,

I hope you get her all back together and working good. Now this may be a stupid question but have you made sure that the pitch is the same on the bar sprocket and rim sprocket. Also that the gauge of the chain and bar match. Seems like I read about some odd ball sizes from time to time like .365.

I really don't know enough yet and I enjoy all the folks here. I hate to admitt it but I even miss the sap guy. Funny reading that was. He would probably make a good neighbor but I cant say I would agree with him to much. It takes all kinds to make the world go around.

Anyway Happy Thankgiving

v/r

Mike
 
Like The Woods! said:
"If you'v changed your rim sprocket and used something other then stihl brand the fit will be to loose and may slip."

The sprocket and chain was not stihl. They were however new. Have been running them for a while. The extra drum to be installed is not stihl either. I guess I better stick with OEM.

"Man you tore that one up pretty good. Was the bar sprocket seized up or binding? If so I would suspect that. If not I would hazzard a guess and say not enough oil/lube + big dry beech + maybe some dirt/debree and maybe the chain was being pinched or binding in the cut. If you add all those up it might do it."

A couple of weeks ago my son slipped in some Stihl bar oil, unbeknown to me. I immediately noticed the difference. The bar/chain was showing a lot of oil. It converted me to using Stihl, instead of Wally World.

I have always had the oil adjustment open fully. Yesterday I turned it to half.
So maybe it was a combination of 'stuff" that happened to cause this.

Appreciate your help!
oem isn't necessary- but, an oregon rim will run on a stihl drum but not for long. will do what your's did. don't feel bad i've seen shop's do that. have a good thanksgiving all.
 
When you by a new drum kit, make sure it's for the 026-PRO. The standard 026 drum is different.

Als, be sure you engage the oil pump drive arm into the drum notch before putting on hte washer and clip.
 
sugarbush said:
If you'v changed your rim sprocket and used something other then stihl brand the fit will be to loose and may slip.

Maybe in that smaller saw, but not in all of the 660's and 460s I have. All of my replacement drums, bearings, sprockets and clips and washers are all Oregon brand. I mix and match all the time.
 
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This site and myself share something....We are both sooo full of it:greenchainsaw:

This site if full of good, knowledgeable people...

I am full of _______ fill in the blank. My wife of 40 yrs. can help you.

I do hope to post more. I'm an old sucker, and the last thing I do before bed is read on this forum. At this time of night I don't have the energy to post or do much of anything. My wife of 40 yrs. can help you fill in that blank also.:blush:

Actually we were married on the day after Thanksgiving. I was home on leave, and had to go back to a small conflict in ther orient...Just like a 40's old movie. Such is life, and as long as I have such a good family, and can keep lifting the chainsaw, it is good.

Best wishes to all.
 
soo... don't go forgetting that anniversary then! Mines the 25th, and it's so easy to get that missed around thanksgiving. I only ever forgot one - the FIRST anniversary... but that's another story...


yes, life is good..
 

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