Ms 261 won't idle.

miller755

miller755

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Hello, I have recently acquired a few ms261s I believe they are that mtronic model. They're all 2018 or newer and they have wires going to the carb. Anyway two of them won't idle, does this point to a common issue? They seem to run pretty good, but need to be started off idle. I put new known good fuel in them, so that's not the issue.
 
MagraAdam

MagraAdam

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hey mate, I'm no expert on saws and also never worked with an m-tronic one before, but I assume you've checked the air filter and spark plug, and also made sure the plug boot is clean and making good connection?

Do they idle at half choke, idle with the air filter removed? these might help. oh, it could be the fuel filter too. I had an issue with my 170 where it just wouldn't idle and it was the exhaust spark screen being clogged up.. cleaned that and it was like a brand new saw.

also, this thread may be of assistance: https://www.arboristsite.com/community/threads/mtronic-idle-adjustment.334119/
 
PA Dan

PA Dan

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Here's a MS170 spark screen that started and ran awful. After removed it ran perfect. Smoked for a bit.
055beb5183adad57720f000adb559960.jpg
 
Motherboard

Motherboard

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Here's a MS170 spark screen that started and ran awful. After removed it ran perfect. Smoked for a bit.
Oh boy, that's quite a restriction.
Maybe the OP should take off the mufflers and look how the piston and what he can see of the cylinder looks like,
check for scores or other damage before spending money elsewhere on the saws.
 
PA Dan

PA Dan

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Oh boy, that's quite a restriction.
Maybe the OP should take off the mufflers and look how the piston and what he can see of the cylinder looks like,
check for scores or other damage before spending money elsewhere on the saws.
I went through the saw. All was good. Added a carb kit, fuel line and filter. Ran some good fuel and oil through it and found it a new owner.
 
MagraAdam

MagraAdam

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Here's a MS170 spark screen that started and ran awful. After removed it ran perfect. Smoked for a bit.
055beb5183adad57720f000adb559960.jpg
same as mine. I'd suggest taking the muffler off and soaking it in unleaded overnight (with a lid on to stop evaporation) and you'll get a heap of carbon come out of it too. let it dry fully then it'll be almost new.

As for the screen, I suggest leaving it in, just either clean it or buy a new one and then keep it clean. they serve a very valid purpose (though i have seen many threads on here with people "angry" at the govenrment or companies for making people run them, but i prefer not to start fires..)
 

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