Stihl MS260 rattle

[spudulike]

Pressure,vac,compression checks, check the tank vent, strip and clean the carb and finally tach tune the machine.

 

Normal checks I do on saws that have seized.

[NorfolknGood]

Pressure,vac,compression checks, check the tank vent, strip and clean the carb and finally tach tune the machine.

 

Normal checks I do on saws that have seized.

 

I can do the carb and tank vent but no facilities for the rest

[spudulike]

I can do the carb and tank vent but no facilities for the rest

 

You could set it up as standard - one turn out on each of the carb screws and then get another to do the checks if anything isn't quite tight. Not the way I do things but may work out for you!

 

I like to make sure that my repairs stay that way but I am kitted out do do so!

[NorfolknGood]

New piston and rings fitted wow talk about increase in compression!

 

Slight rattle type sound but not like before and when the clutch comes in and spins the chain the rattle stops so must be in clutch. I checked visually for leaks/cracks in everything and set the carb to 1 and a tad turns on both needles and set as necessary when running.

 

Regarding cause of problem in the 1st place I did notice the pot gasket had a break in it so potentially been drawing in air there which could cause a lean run and partial seize.......... new gasket fitted

 

A chain catcher has been fitted which was missing 1 last thing needed is a replacement top hat type washer that holds the lhs of the brake lever, it's missing right now.

 

Engine starts and runs very well now but having back issues I need that decompresser valve now I have compression!

 

Many thanks chaps for all your input it's been a great help

[MATTMOSS]

I have not checked needle bearings in the clutch housing but have revolved it by hand and it does have a little play in it which I assumed was normal? If not that's a good source of the right noise I would think

 

I will try the shake rattle and roll thing in the morning, I think it's time to come in now or SWMBO will cut my tail off!

 

I did remove the exhaust and found 1 of the bolts that hold the lid on loose and under the exhaust some resin like packed in saw dust so had a good clean up. The bore looks perfect and piston has slight scoring as you may expect from a 2005 saw that looks like it's had commercial use. I guess in an ideal world i would strip it cross hone and replace rings etc but for now I just want to get it running without the rattle.

 

I can give it an hour or 2 tomorrow so maybe I can find Mr Rattle then.

 

Its not normal, it means your needle bearing is worn and continual use will score your crank shaft, which will lead to needing a new crankshaft = full rebuild= lots of money and time== change the needle bearing

good luck

[MATTMOSS]

Would you agree with this Spud?

Matt

[Rich2484]

The needle bearing failure will cause a loss on the drum, smashing the clutch and anything behind the clutch.

 

Was a thread a while ago with an ms026 that done exactly that. Div-h saw done it.

 

The scoring on the crank would be caused by the drum rattling around it. Would have to destroy the round big washer behind the clutch before getting to the crank seals. Oh and work through the worm drive aswell.

 

A needle bearing failur wouldn't mean it would damage the crank into the crank case but would destroy a lot before it gets there.

 

No play should be on the bearing with the drum on. Of course it could be a worn drum or crank other than the needle bearing itself. These are normally visual that they have gone.

[NorfolknGood]

Well for the sake of a few quid (£2.90) and 2 mins work I will replace the bearing

I did notice though that the clutch housing appeared out of round when I spun it by hand but when running the saw and the clutch engaging by slowly increasing the revs it does not judder it works as it should

[Rich2484]

Can I ask for curiosity what sprocket type you have on the saw?

 

If its out of round could it be catching on the worm gear drive arm??? Knocking in and out of it. Also check if the big washer is flat and not bent.

 

The clutch is working as it should.

[MATTMOSS]

Well for the sake of a few quid (£2.90) and 2 mins work I will replace the bearing

I did notice though that the clutch housing appeared out of round when I spun it by hand but when running the saw and the clutch engaging by slowly increasing the revs it does not judder it works as it should

 

As the clutch engages it will centre the clutch drum anyway, but if there is any other movement apart from rotation when the saw isn't running and the chain brake is off -that's not good. Its always hard to give advise when you cant physically see it but If you think its not running perfectly symmetrically - change it. By what else you've said It will probably due for replacement anyway especially if its a spur sprocket.

You will soon have a brand new saw at this rate!