Stihl MS 261 misbehaving, advice please?

[Bryapatch]

Hi there,

 

The 261 i use at work is fairly new, bought in the autumn. Its been great untill this week when it was borrowed and used for 40 minutes or so when it was really too blunt to be used, it had started to burn the wood. I have now sharpened it but it is behaving strangely:

 

1. It will not start with the chain brake on.

2. When I take the chainbrake off, the saw will start, but the chain spins round will ticking over, even though the chain is properly tensioned.

3. When i put the chain brake back on when it is running, the saw stalls.

4. The chain also goes really slack so its hanging off the guidebar when the chain brake is off, and tight again when the chain brake is on.

 

Any insight into whats gone wrong would be great, dont really trust our local power tools shop as they have completely failed to repair chainsaws sent to them in the past, so id like to have an idea about whats wrong. I havent had a chance to take the saw apart and examine in it, could a broken clutch spring explain some of the symptoms?

 

Cheers

[GardenKit]

Hi there,

 

The 261 i use at work is fairly new, bought in the autumn. Its been great untill this week when it was borrowed and used for 40 minutes or so when it was really too blunt to be used, it had started to burn the wood. I have now sharpened it but it is behaving strangely:

 

1. It will not start with the chain brake on.

2. When I take the chainbrake off, the saw will start, but the chain spins round will ticking over, even though the chain is properly tensioned.

3. When i put the chain brake back on when it is running, the saw stalls.

4. The chain also goes really slack so its hanging off the guidebar when the chain brake is off, and tight again when the chain brake is on.

 

Any insight into whats gone wrong would be great, dont really trust our local power tools shop as they have completely failed to repair chainsaws sent to them in the past, so id like to have an idea about whats wrong. I havent had a chance to take the saw apart and examine in it, could a broken clutch spring explain some of the symptoms?

 

Cheers

Its almost certain to be the now commonplace failure of the clutch drum needle bearing. along with possible wear/damage to the inside bore of the drum itself.

 

There are plenty of recent threads on here about this problem.

 

Oh, and by the way, welcome to Arbtalk.

[chainsawdom]

mines now starting to rattle badly and vibrating from the clutch drum when under load i got mine from fr jones when they first came out so iam now wondering if mines a dodgey one mines only done about four hours work max from new as ive still got a 346 and cant seem to stop using it so i wonder if stihl will sort mine under warrenty.

[pleasant]

Its almost certain to be the now commonplace failure of the clutch drum needle bearing. along with possible wear/damage to the inside bore of the drum itself.

 

There are plenty of recent threads on here about this problem.

 

Oh, and by the way, welcome to Arbtalk.

 

I agree. Certainly the first thing to check.

[Graham]

Could also be a broken clutch spring.

[Martyn Amos]

Could also be a broken clutch spring.

 

agree with that 100%

 

had the same problem with a 254xp,if you put the chain on saw would cut out,if brake was off chain would spin..

 

problem,snapped spring in clutch..

[Tom D]

Mine is exactly the same, I thought clutch springs... and ordered a new set, haven't got round to fitting them yet, we just use it with out the chain brake. Might have to order a bearing then.

[Bryapatch]

Thanks a lot for the replys. I will have a looksee tomorrow. Reassuring that neither needle bearing or clutch springs will cost the earth. I'll be sure to carry grease in future, even if it isnt the needle bearing thats broken. Cheers

[spudulike]

From one of yor symptoms - the chain goes from loose to tight when the chain brake is applied.

 

This is a strong indicator that your sprocket needle bearing has failed and badly by the sounds of it - don't run the machine, you may cause further damage to the crankshaft!

 

Take the side cover, bar and chain off and check the sprocket for tightness on the bearing or just pull the clutch drum/sprocket off and inspect it - my money is on this - a clutch spring would cause SOME of your symptoms but would NOT cause this one!

 

Your needle bearing cage has probably cracked and has probably thrown your needle rollers out of the bearing:thumbdown:

 

If it is under warranty - inform your dealer, there appears to be a recall for this fault!

[Bryapatch]

Fixed it today, it was the needle bearing! When i took everything off it was completely shagged and just fell away. New one on now and after a brief test all the symptoms have stopped. Will wait and see how it performs on a full day's work. Couldn't see anything obviously wrong with the clutch springs or the drum. My saw has a twin bought at exactly the same time from the same place, and its needle bearing is fine, will try taking mine back if it happens again. Thanks a lot for the advice guys, invaluable forum. :-)