Stihl MS 211/c idle issue

[John Rainford]

I've learnt a bit about my saw from spudulike and others who have helped me solve a couple of issues over the years. I have succesfully stripped the saw right down to a minimum , replaced the crank seals and put it back together, as well as other easier things. I have a new issue at the moment which I need to solve and am having problems with it. The saw starts fine, idles for a minute or two and then cuts out. I did a bit of research on "Steves small engine saloon" on you tube and tried a few things, but no success yet.

Cleaned the plug and the air filter

Checked the h and l screws were correctly positioned

Pulled the carb and used carb cleaner to blow through the internals, as well as inspecting the Diaphragm

While it was idling, I turned the idle screw in, expecting the revs to increase and at some point the chain to start moving. However, I turned the idle screw all the way in and the revs failed to increase and the chain did not start moving.

 

I am thinking of buying a new service kit and trying fresh fuel. It's time for a service anyway.

 

Any help with diagnosis would be appreciated.

[Stubby]

7 hours ago, John Rainford said:

I've learnt a bit about my saw from spudulike and others who have helped me solve a couple of issues over the years. I have succesfully stripped the saw right down to a minimum , replaced the crank seals and put it back together, as well as other easier things. I have a new issue at the moment which I need to solve and am having problems with it. The saw starts fine, idles for a minute or two and then cuts out. I did a bit of research on "Steves small engine saloon" on you tube and tried a few things, but no success yet.

Cleaned the plug and the air filter

Checked the h and l screws were correctly positioned

Pulled the carb and used carb cleaner to blow through the internals, as well as inspecting the Diaphragm

While it was idling, I turned the idle screw in, expecting the revs to increase and at some point the chain to start moving. However, I turned the idle screw all the way in and the revs failed to increase and the chain did not start moving.

 

I am thinking of buying a new service kit and trying fresh fuel. It's time for a service anyway.

 

Any help with diagnosis would be appreciated.

@spudulike

[spudulike]

Has the L screw still got the rev limiter fitted on it? If the L screw is turned in fully, the saw revs should rise and then die. If it doesn't do this, I would suspect an air leak.

[John Rainford]

Thanks for the reply. L screw still has the plastic limitor cap. I will try turning it in to see if it revs and then dies and post again.

[spudulike]

With the limiter fitted, you won't be able to get the same feeling on the adjustment as you would with a non limited carb adjustment.

Is the saw fitted with a bar and is it stalling on the strop, on the floor, being held....it all makes a difference.

Have you checked the clutch springs, if they are a bit baggy or one is broken, the saw will stall on idle.

[John Rainford]

Appologies for not responding to the replies to my posting. My 92 year old mum contracted the dreaded virus and ended up in hospital, which put a spanner in the works. Thanks for the replies. I put a new service kit in because it was due anyway. This didn't make any difference. I'm starting the saw with the bar and chain on. I did get it going and idling for a few minutes a couple of times and then the next time it was back to cutting out at idle almost immediately. It happens while holding the saw and if I put it on the work bench.While I did have it idling I rotated the saw on both sides to see if it made any difference to the revs, but no change on either side, or tipping the saw down. I did what spudulike suggested and while idling, turned the L screw (limitor cap fitted) all the way in, but there was no change in revs as would be expected, so I now have the L screw not functioning as well as the Idle screw. Air leak ?. I will take a look at the clutch springs today. I have put the carb screws back to factory settings for now.

[John Rainford]

Appologies for not responding to the replies to my posting. My 92 year old mum contracted the dreaded virus and ended up in hospital, which put a spanner in the works. Thanks for the replies. I put a new service kit in because it was due anyway. This didn't make any difference. I'm starting the saw with the bar and chain on. I did get it going and idling for a few minutes a couple of times and then the next time it was back to cutting out at idle almost immediately. It happens while holding the saw and if I put it on the work bench.While I did have it idling I rotated the saw on both sides to see if it made any difference to the revs, but no change on either side, or tipping the saw down. I did what spudulike suggested and while idling, turned the L screw (limitor cap fitted) all the way in, but there was no change in revs as would be expected, so I now have the L screw not functioning as well as the Idle screw. Air leak ?. I will take a look at the clutch springs today. I have put the carb screws back to factory settings for now...........  #just looked at the clutch springs, they seem fine. Some additional info - Blowing a lot of white smoke and black oily deposits being omitted from the exhaust. It seems to be burning through fuel very quickly.

[Stubby]

4 hours ago, John Rainford said:

- Blowing a lot of white smoke and black oily deposits being omitted from the exhaust. It seems to be burning through fuel very quickly.

Have you mistakenly filled it with deisel ?  If so stock up on Yorkie bars and keep on truckin' 🙂

[spudulike]

Just read this again, the idle screw turned all the way in should bring the saw up to mid revs.

If you get no increase in revs, the saw is either running very rich or something else is amiss.

Are all the linkages on the carb working and fitted correctly? The strato air valve should open as the main throttle valve opens. 

Is the saw picking up and revving out OK and the issue is just the idle?

 

[John Rainford]

Appologies for not responding to the replies to my posting. My 92 year old mum contracted the dreaded virus and ended up in hospital, which put a spanner in the works. Thanks for the replies. I put a new service kit in because it was due anyway. This didn't make any difference. I'm starting the saw with the bar and chain on. I did get it going and idling for a few minutes a couple of times and then the next time it was back to cutting out at idle almost immediately. It happens while holding the saw and if I put it on the work bench.While I did have it idling I rotated the saw on both sides to see if it made any difference to the revs, but no change on either side, or tipping the saw down. I did what spudulike suggested and while idling, turned the L screw (limitor cap fitted) all the way in, but there was no change in revs as would be expected, so I now have the L screw not functioning as well as the Idle screw. Air leak ?. I will take a look at the clutch springs today. I have put the carb screws back to factory settings for now...........  #just looked at the clutch springs, they seem fine. Some additional info - Blowing a lot of white smoke and black oily deposits being omitted from the exhaust. It seems to be burning through fuel very quickly.