MS210, starts and idles fine, cuts out as soon as power is applied.

[Arghshh]

As per the title, it's an MS210, not sure on age. Starts up perfect, idles fine when cold but if left to idle from cold starts hesitating a bit as it warms up and will cut out after approx 1 min of idling. Once the motor is warm will get harder and harder to start, but will always start and idle for a period.

 

If it's started from cold or warm and the throttle opened it bog down and dies before the chain even starts to move, if I'm super tentative with the throttle I can sometimes get the chain moving but it will bog and die before it even gets half revs. With the chain and bar removed it will bog down all the same.

 

Saw is second hand, looks in very good order, new bar and chain, sprocket bearing is lubed, sprocket rotates freely, spark plug gapped correctly and filters are clean. The saw and everything I can see without stripping it down completely is clean and damage free.

 

The saw ran fine over the last two tanks (I've only had these two tanks through it myself) before trouble started - not a hitch.

 

Changed to Aspen for the last tank before trouble started, ran fine through the whole tank of Aspen.

 

Tried going back to petrol and 2 stroke, same problems.

 

Checked carb settings, both needles were already set to factory settings, tried running it more rich - no improvement.

 

Any advice greatly appreciated before I go bald from pulling my hair out!

 

Ash

[nepia]

You've just described exactly the symptoms of my HS81R hedgecutter that was new in September; it's going back to Stihl as my local menders can't find anything wrong. I realise it's unlikely to be the same problem but I'll keep an eye on this thread in case we can advise each other.

Mine has always started cold, then run fine for anything from 2 to 30 minutes. Then it just dies. Sometimes it'll restart, sometimes it won't. When left to go cold (20 minutes or so) it'll restart but throttling it kills it. Hopeless!

[Graham]

Have you looked at carb? Check diapraghms, blow out all airways and if the exhaust has a spark arrestor fitted chuck it.

[treequip]

Sounds like a fuel starvation problem.

 

If you haven’t already,

 

Make sure the fuel runs ok. Pull the feed pipe of the carb and tip the saw so the fuel runs under gravity. It should flow freely. A new tank filter costs pennies.

Inspect the fuel feed pipe for damage.

 

Check the tank breather.

 

Clean out the carb, there will be is a small sieve in there that needs checking. Make sure the diaphragm is clear and can move properly.

 

Andy

[elfinwood saws]

could be sucking air, flip the saw over and make sure the 4 crankcase screws are tight,

[oldwoodcutter]

If its any help my new HS81R just wouldn't run properly,exactly as your first 2 paragraphs.Local dealer said its to do with lean running and emissions law.But ive solved it by trial and error - i start it on full choke and keep it on 1\2 choke for first 10 minutes,then its fine all day.Hope this helps.

[nuggsy]

i had same problem with a 210, i replaced the diaphragm and feul filter the only thing i didnt replace was the breather but i have since heard the breather is at fault

[nepia]

If its any help my new HS81R just wouldn't run properly,exactly as your first 2 paragraphs.Local dealer said its to do with lean running and emissions law.But ive solved it by trial and error - i start it on full choke and keep it on 12 choke for first 10 minutes,then its fine all day.Hope this helps.

 

 

Thanks for that. I'll definitely give it a go - if I can start it up; got it going yesterday and it died after ~30 seconds.

 

Jon

[Arghshh]

i had same problem with a 210, i replaced the diaphragm and feul filter the only thing i didnt replace was the breather but i have since heard the breather is at fault

 

I checked the breather on mine, I took it off and tried blowing in the top of it and seemed like a bit of fuel popped out, possibly a bit of crud. Is the breather only supposed to work one way as blowing from the tank end there is no through flow but sucking from the tank end it seems ok. I assume this is correct as the carb draws fuel in the breather will have to draw air in so as not to create a vacuum in the fuel tank.

 

Andy - thanks for the advice. I stripped the carb and I don't know if I contaminated it when I stripped it but there was the smallest trace of grit on the fuel pump side of the carb, I give it a clean out and blew through the fuel holes and checked the mesh, all seemed good. I hope the grit/muck was me and not ingress over time = possible piston etc damage! Incidentally the fuel pump diaphragm was quite plasticy, shiny and stiff, i.e not a soft flexible material like the metering diaphragm, I guess this is not good?

 

I'm new to carbs so I suppose this is turning into a 'how does this work?' topic, sorry.

 

Ash

[Arghshh]

could be sucking air, flip the saw over and make sure the 4 crankcase screws are tight,

 

Forgot to check this, will do in the morning.