Chain wont stop at idle even after adjusting

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mybabybook

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Hi,
it is the Stihl 08s. I bought it recently. When first tested, it was all ok, but next time I noticed chain spins at idle. Today, I have adjusted the idle screw, by turning counter clockwise as suggested in manual. The chain stopped spining after maybe 2 full turns of the screw. When I gave it full throttle and let go, it kept spinning again. What might be the problem> According to person who sold it to me, it did have a recent service, with carb adjustment.
 
How do I do that? I mean will have to remove sprocket cover and sprocket to get to clutch. And what should I look for then? As far as I know, there are 3 springs on the clutch, how to check if they are weak.
 
Your low speed mixture is probably just set too lean, try backing it out 1/4 turn and see if it gives a lower consistent idle speed. The idle speed screw just sets the throttle stop position and has nothing to do with the mixture. Don't get misled into clutch issues until you have the correct idle sorted out.
 
How do I do that? I mean will have to remove sprocket cover and sprocket to get to clutch. And what should I look for then? As far as I know, there are 3 springs on the clutch, how to check if they are weak.

I have never had to deal with it. I have some extras, you may not. In such a case see if you can tighten one or two coils, maybe with some zip ties. By no means a solution, but to see if that ALONE changes the situation.
 
Thanks guys. As some of you suggested adjusting the Low speed screw, I want to ask first- can I mess it up playing with the L screw, as someone has told me if done incorrectly, engine problems may occur.
Also, should I turn it clockwise or anti clockwise to make it richer?
 
Thanks guys. As some of you suggested adjusting the Low speed screw, I want to ask first- can I mess it up playing with the L screw, as someone has told me if done incorrectly, engine problems may occur.
Also, should I turn it clockwise or anti clockwise to make it richer?
That is possible if you dont understand anything about how an engine sounds.

Its obvious when a saw is to lean to pretty much anyone. It will over-rev and can fail to lubricate enough. Then it usually glazes the cylinder and flakes it off.

Worst you are gonna do making it richer is foul a plug that probably could use changing anyway.

You know how some saws rev up really really high when they are about to run outta gas?

That is too lean conditions. Thats what it sounds like.
 
Mine sounds OK, at least to me> Have forgotten to say- i did tension the chain on arrival, but after warming up, there is a noticeable sag. I did not re-tensioned it as was not going to use it anyway and left like that. What I am thinking of is, that I would better make a short video of how it sounds at idle, so that you can say if it sound ok or not, as as I said, it does sound OK to me, but I might be wrong as well.
 
Thanks guys. As some of you suggested adjusting the Low speed screw, I want to ask first- can I mess it up playing with the L screw, as someone has told me if done incorrectly, engine problems may occur.
Also, should I turn it clockwise or anti clockwise to make it richer?

The threads are fine on the carb. If you don't see a change with small turns, then back off. Over tightening or loosening the H/L/Idle is going to harm the carb. If the problem IS the carb and minor adjustments don't fix the problem, then you likely should do a carb rebuild and a cleaning in an ultra sonic bath.
 
By adjusting the low you can’t do damage.
Here’s how I deal with the Low. I turn in the idle till the chain is turning, then I turn in the low to get the highest rpm, then I back it out about 5 minutes, then adjust idle till chain stops turning. This of course starting with a warm saw. You may have to do this a couple of times to find the sweet spot.
This is all about getting instant throttle response. If saw bogs at throttle try backing out L some more till it doesn’t.
 
Over tightening or loosening the H/L/Idle is going to harm the carb.
I am not sure how much i loosened the idle screw. I am sure I done at least 2 full turns, but did not tightened it again, just left like that. With that being said, should I tighten it again, lets say 2 turns, and then start the procedure Gypo suggests?
 
I am not sure how much i loosened the idle screw. I am sure I done at least 2 full turns, but did not tightened it again, just left like that. With that being said, should I tighten it again, lets say 2 turns, and then start the procedure Gypo suggests?
you can download the owners manual free from Stihl. Gives you good instructions on adjusting the carb and your idle. Here is the file.
 

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I did adjusted the idle using the manual. It says to turn it counter clockwise until chain stops running. I did that, but did not count how many turns counter clockwise I did. So that I can return it in same position now. Will try to take apart and check the clutch whenever I get time to do so.
 
I did adjusted the idle using the manual. It says to turn it counter clockwise until chain stops running. I did that, but did not count how many turns counter clockwise I did. So that I can return it in same position now. Will try to take apart and check the clutch whenever I get time to do so.
Turn the idle screw closed all the way. Then open 1 full turn. Start saw and adjust from there until the chain stops spinning .
 
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