# Stihl M-Tronic problems



## OpenCanopyTree (Jan 8, 2017)

Anyone else out there having problems with their M-Tronic carbs?
My 201 t-c recently started acting up. At idle the chain would still be spinning quite quickly, and nothing I could do would remedy the issue. I brought my saw into the dealership on December 12th, and they still haven't gotten an answer out of Stihl. Pretty inconvenient considering it is my only top handle, and I'm a climber. 


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## deelgaarddevil (Jan 8, 2017)

I am not familiar with m tronic carbs, but a friend of my had almost the same problem and he gave the carb a good old punch with a hand and it worked [emoji23].....

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## Firemoore98 (Jan 8, 2017)

I have the exact same saw as yours and zero issue. Wish I could help, heck if you lived closer I'd let you borrow my ms201TCM

Keep us posted on what they come up with, I always like to know common problems for a model I own. 

Jason


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## Conquistador3 (Jan 8, 2017)

I will ask my Stihl dealership this week if they ever had a similar problem. Honestly the only problem I've had with M-Tronic so far is the much advertised "fuel savings" only exist on paper but I am OK with it if this means the saw runs a little richer.


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## deelgaarddevil (Jan 8, 2017)

But if the chain is spinning quickly at idle its pretty dangerous if you are high up in a tree... well then you have to master the chainbrake[emoji6]

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## RiesePING (Jan 8, 2017)

OpenCanopyTree said:


> nothing I could do would remedy the issue.
> 
> 
> Sent from my iPhone using Tapatalk Pro



What did you try to do to fix it?


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## CR500 (Jan 8, 2017)

Did you try your summer/ winter shutter?

This happened on my 441 one night when it was about10-15 out.

I moved the shutter to the winter position and it stopped the chain spinning at idle. 

In the summer position in the summer I had no issues 

Sent from my non internal combustion device.


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## newforest (Jan 8, 2017)

On November 20th I gave a saw back to my local dealer. It was running rich since the day I bought it. I managed to put about 50 hours of use on it before it would just foul a new plug in about 20 minutes or so. Still no word back from the dealer, the distributor, or Stihl.


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## Firemoore98 (Jan 8, 2017)

newforest said:


> On November 20th I gave a saw back to my local dealer. It was running rich since the day I bought it. I managed to put about 50 hours of use on it before it would just foul a new plug in about 20 minutes or so. Still no word back from the dealer, the distributor, or Stihl.



Sorry to hear about that, darn long time to be down a saw. 

What model was it? M-tronic?

Jason


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## svk (Jan 8, 2017)

If your dealer cannot figure out the problem in a reasonable amount of time then your only option is to find a different dealer who can. If you drop the coin on a pro saw and rely on it to put food on the table they shouldn't be sitting on it for weeks.


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## newforest (Jan 8, 2017)

It was a model rarely sold in the USA, a 560 C-M clearing saw (M = M-Tronic). I am working in Virginia this winter and am a little tempted to walk in the front door of Stihl USA and ask a few questions. Though I asked around my hometown about this dealer (my first purchase from them) and had good feedback about them, it is pretty clear to me that they aren't qualified to handle M-Tronic questions. At one point the owner said he had to get a new laptop to operate the M-Tronic diagnostic software - about 3 weeks ago.

I learned fuel injection systems owning a 1980s vehicle and it was sometimes kind of nice to discover how simple things like cleaning a ground point could cure problems in those early systems. So sometimes I am optimistic that it will prove to be a easy fix.

But at this point I know I am just unlucky to have purchased from a dealer with too low of a volume selling for professional use. When I noted that they wouldn't even stock an MS 261 due to no demand, I should have walked out and found a more experienced dealer. But those are hard to come by in a business that mostly caters to weekend warriors. Imo. That and the 3 tier system Stihl uses seems to possibly create a game of pass-the-buck amongst the three businesses one actually purchases a piece of Stihl equipment from: local dealer - distributor - Stihl USA. The 'distributor rep' always seems to be unavailable for a week or more at a time, for one.

Though I have had much better luck with 2 Auto-Tune saws, I know that one bad saw does not make M-Tronic a bad system. Nor does a local dealer without much experience with M-Tronic saws make for a bad manufacturer network. My closest local Husqvarna dealer won't even sell an Auto-Tune saw, or service one.


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## svk (Jan 8, 2017)

After owning both I think MT seem to tune a little better than AT. 

In my experience, many Stihl dealers don't even know their entire saw pro lineup so that doesn't give me much faith in their ability to fix MT issues. And we've certainly seen enough cases on here of some Husky dealers being totally in the dark when it comes to diagnosing AT issues.


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## Ozhoo (Jan 8, 2017)

The beauty of m-tronic is in it's simplicity. There's only 3 parts... a flywheel, control unit and carb. Worst comes to worst, you swap em out. No software to load or update... nothing.

I would be holding that dealer's feet to the fire. There's no excuse to not have it fixed.


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## newforest (Jan 8, 2017)

Sure there is an excuse - which of the 3 businesses will pay for the swapped out part? It should be simple, yes.

My ultimate goal is to re-build a small fleet of these saws, coming from owning several similar non-AT / non-MT saws. I like the idea of modular components, just switch out and go back to work. I can't say I am leaning towards using the Stihl version for that, right now. Or spending another dollar at this particular dealer. But I know A-T and M-T are the future, and it has already arrived.

I sometimes wish the manufacturers of "Pro" grade equipment would identify which of their dealers are "Pro" grade.


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## svk (Jan 8, 2017)

newforest said:


> Sure there is an excuse - which of the 3 businesses will pay for the swapped out part? It should be simple, yes.
> 
> My ultimate goal is to re-build a small fleet of these saws, coming from owning several similar non-AT / non-MT saws. I like the idea of modular components, just switch out and go back to work. I can't say I am leaning towards using the Stihl version for that, right now. Or spending another dollar at this particular dealer. But I know A-T and M-T are the future, and it has already arrived.
> 
> I sometimes wish the manufacturers of "Pro" grade equipment would identify which of their dealers are "Pro" grade.


Stihl has some type of designation for better dealers. I believe it's bronze, silver, gold, and platinum?


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## hedge hog (Jan 8, 2017)

My dealer is platinum and my 441 c m trough him and I for loop 
Running poorly,dying in the cut 
Had hooked to the laptop 3 different times
every part passed the test 
But would fail the completed test
So he sent the results to Germany and they had no idea what was wrong 
They told him replace all three parts to make sure
But didn't help

After the third time home and it was still acting funny but not all time 
So I did a very good cleaning on it one night and seen carbon build up around the decompression hole and showed him the next day 
He plugged it because I never use it
It has never missed a lick since 


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## OpenCanopyTree (Jan 8, 2017)

Ozhoo said:


> The beauty of m-tronic is in it's simplicity. There's only 3 parts... a flywheel, control unit and carb. Worst comes to worst, you swap em out. No software to load or update... nothing.
> 
> I would be holding that dealer's feet to the fire. There's no excuse to not have it fixed.



I've realized now that I brought it to the wrong dealership to fix it. Going on a month now, and they're trying to tell me Stihl has no answer for them, and that the saw may need to be sent to Edmonton (250kms away) to be analyzed. Thank god it's winter, and I'm not using the thing every day!


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## OpenCanopyTree (Jan 8, 2017)

CR500 said:


> Did you try your summer/ winter shutter?
> 
> This happened on my 441 one night when it was about10-15 out.
> 
> ...



Yes, tried that along with a few other things. Only thing that would slow the chain down was the brake! 


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## OpenCanopyTree (Jan 8, 2017)

RiesePING said:


> What did you try to do to fix it?



Tried to recalibrate it by following the 5 cut instructions in the manual. Then took apart the saw to see if there was any way to manually adjust the carb. No luck there so went to throttle cable, with no luck. This new M-Tronic system gives us no way to tweak the carb. 


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## newforest (Jan 8, 2017)

I think carbon build-up might be a problem in my saw. Or, it is definitely a problem and it creates worsening feedback effects. It plugged the muffler screen before a gallon of fuel had been run through it, starting with Stihl MotoMix. I suspect the carb jet diameter might be a tad bigger than M-Tronic thinks it is. I ran it with no screen until it wouldn't run.

I don't think the M-Tronic system has anything analogous to an O2 sensor on a vehicle engine, which gives the injector controller some data on the results of controlling the fuel/air mix. In my very un-learned opinion, this means all of the hardware has to perform perfectly, like the software is assuming it does. I could also be totally wrong on my hunch.

I know there is an altitude sensor of some sort in the M-Tronic controller but I don't know which other data it 'senses'. One bad sensor changes everything.

The idea of individual parts passing the diagnostic software tests but not the whole system concerns me.

My saw also has a winter/summer hard setting that I never tried. I never ran it in below freezing temps, though some in relatively 'cool' weather = 40º F 


I like that the software keeps track of run-time, I had not heard that before. I would like to access that data myself.


I am on work that doesn't need a clearing saw, until probably June, so I'm not pushing any buttons on trying to get the saw fixed fast. That would just get me more pointless declarations of "we know that model well." Maybe my saw is in Dayton or Virginia Beach by now, who knows. I tried to give it back to the dealer the morning after I bought it; they insisted it was fine.


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## newforest (Jan 8, 2017)

Oh and I also deleted the de-compression button on my Auto-Tune chainsaws, as I wasn't using them and when I flooded one once, it showed excess oil leaking at the button threads. The grommet around the now vertical button would ride up and make it hard to tell if it had been pushed, and didn't seem to help start it that much anyway. My very good Husqy dealer told me Auto-Tune starts easier if you flip the choke on and immediately back off again, even when the saw is already warm. That plus using the primer bulb plus the decompression button and the known vapor-lock potential made it all more complex than necessary, I forgot the sequence I needed on a warm day and I flooded one. They seemed easier to pull over without the de-compression button than non Auto-Tune XPs I have run previously and I haven't missed it.

But the Stihl saw I am having trouble with doesn't have one of those buttons, though it does have their Easy Start system of some sort, or whatever they call it, I'm sure with a ™. It starts real easy but maybe there is some sort of automatic decompression involved, don't know. I didn't expect to have much trouble with a saw in it's 4th model year of use.


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## hedge hog (Jan 9, 2017)

newforest said:


> Oh and I also deleted the de-compression button on my Auto-Tune chainsaws, as I wasn't using them and when I flooded one once, it showed excess oil leaking at the button threads. The grommet around the now vertical button would ride up and make it hard to tell if it had been pushed, and didn't seem to help start it that much anyway. My very good Husqy dealer told me Auto-Tune starts easier if you flip the choke on and immediately back off again, even when the saw is already warm. That plus using the primer bulb plus the decompression button and the known vapor-lock potential made it all more complex than necessary, I forgot the sequence I needed on a warm day and I flooded one. They seemed easier to pull over without the de-compression button than non Auto-Tune XPs I have run previously and I haven't missed it.
> 
> But the Stihl saw I am having trouble with doesn't have one of those buttons, though it does have their Easy Start system of some sort, or whatever they call it, I'm sure with a [emoji769]. It starts real easy but maybe there is some sort of automatic decompression involved, don't know. I didn't expect to have much trouble with a saw in it's 4th model year of use.



What model of Stihl?


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## Conquistador3 (Jan 13, 2017)

OpenCanopyTree said:


> Anyone else out there having problems with their M-Tronic carbs?
> My 201 t-c recently started acting up. At idle the chain would still be spinning quite quickly, and nothing I could do would remedy the issue. I brought my saw into the dealership on December 12th, and they still haven't gotten an answer out of Stihl. Pretty inconvenient considering it is my only top handle, and I'm a climber.



Sorry for the delay. I had the occasion to ask my Stihl dealership. The first thing they asked me is "Did he take it to a dealership qualified to work on M-tronic?". Apparently, at least here, not all Stihl dealership are. 

Having said that they told me doing a diagnosis by "word of mouth" is extremely hard, but it sounds like a problem caused by either the carburetor or the solenoid governing it. Again, a repair technician trained to deal with M-Tronic would be able to quickly find which one is the problem.


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## blsnelling (Jan 13, 2017)

No altitude sensor. It measures RPM only and constantly adjusts it, always adjusting for optimal tune. Altitude, weather, fuel, etc, all affect the tune of a saw. It doesn't measure all those inputs. It measures the affect they have on RPM and adjusts the tune accordingly.


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## SawTroll (Jan 13, 2017)

Is this about an early 201, or is it a fairly recent one?


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## SawTroll (Jan 13, 2017)

blsnelling said:


> No altitude sensor. It measures RPM only and constantly adjusts it, always adjusting for optimal tune. Altitude, weather, fuel, etc, all affect the tune of a saw. It doesn't measure all those inputs. It measures the affect they have on RPM and adjusts the tune accordingly.



That is how I understand it as well.

If it actually is the MT that makes the problems, and it doesn't just get the blame for it (happens), I understand it is likely an issue with some solenoid, that isn't working right? There also is a chance that the true issue is with the carb, and not with the MT.


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## blsnelling (Jan 13, 2017)

Yes. The most common point of failure of a MTronic setup is the solenoid on the side of the carb. IIRC, they're <$20 and very easy to replace.


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## OpenCanopyTree (Jan 13, 2017)

SawTroll said:


> Is this about an early 201, or is it a fairly recent one?



Purchased it in November 2015


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## OpenCanopyTree (Jan 14, 2017)

Conquistador3 said:


> Sorry for the delay. I had the occasion to ask my Stihl dealership. The first thing they asked me is "Did he take it to a dealership qualified to work on M-tronic?". Apparently, at least here, not all Stihl dealership are.
> 
> Having said that they told me doing a diagnosis by "word of mouth" is extremely hard, but it sounds like a problem caused by either the carburetor or the solenoid governing it. Again, a repair technician trained to deal with M-Tronic would be able to quickly find which one is the problem.



Thanks for getting back to me. The shop I took it to was not equipped to service it properly. I asked when I dropped it off, and was told they were.... needless to say, I won't be going back after this nightmare ends. 
Had another member of the forum dm me and suggest they try replacing the solenoid with one from another saw off the showroom floor if they had one to see if that fixed the issue. They are ordering in the part now, and we'll see how it all goes. 


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## Khntr85 (Jan 14, 2017)

You need to tell someone about that dumbass dealer, if he had your saw and you depend on it for a living, my friend you are a VERY patient man!!!!!


He should have told you he has no clue orngave you another saw!!!!!

PATHETIC!!!!!


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## Stihldoc (Jan 14, 2017)

I've been a Stihl tech for 34 years. I came into the industry when 031's and 056's were the hot saws. Been there, done that. Mtronic is an excellent engine management system within the limits of its capabilities. What nobody here has addressed is the original issue "the engine runs too fast at idle". Let's put Mtronic aside for a few moments and think about how a competent tech would approach this problem on a non Mtronic saw.
Stihl has a wonderful diagnostic flow chart called "Stihl engine checklist" or something like that. Its simple, but long. Most techs don't bother with it until all their guessing leads them nowhere in solving a problem. I use it when the answer isn't quick and obvious, and it has never let me down. Again. we're pretending this is a standard carbureted saw with a high idle. Most likely, we'd all try adjusting the idle speed screw to correct the problem. I would. But what if that didn't work? Then it gets interesting. We need to systematically look at all aspects of the saw to determine the problem. The diagnostic chart will take us through the fuel system, controls, ignition, exhaust, etc. Lets say that all these items turn out to be ok. The test that will probably be most telling is a pressure and vacuum test of the crankcase. Even a small air leak will cause a saw to run erratically or not at all. High idle could easily be explained by a leak at a gasket, seal, impulse line, or intake boot. If there's a leak, fix it and re-test the crankcase. Now yo can properly set the mixtures and RPM so the saw will run properly.
Now lets go back to an Mtronic saw. Everything thats critical for a carbureted saw to run properly ALSO APPLIES to Mtronic. If you have an obstructed fuel filter or a crankcase air leak, that Mtronic saw won't work properly. Its critical to be sure there are no mechanical problems prior to blaming Mtronic.
Has anyone checked the mechanical parts of this saw, or did they just skip all that because "they knew" its an Mtronic problem???? Mtronic isn't perfect, but it is a simple, generally solid system. What it can't do is magically retune a saw that has an air leak or other mechanical problem. Once all mechanical possibilities are ruled out, only then does a competent tech look at the engine management system.
Hook it up to the laptop and run SDS software. Look at the engine management data- number of starts, total hours of operation, and most importantly- the fuel numbers at idle and WOT. If Mtronic is screwed up, the data and solenoid tests will tell you. If its compensating for an air leak or other mechanical problem, the mixture data will be crazy rich. Mtronic is remarkably simple and usually works perfectly. Sure, there are issues with very early controllers whose firmware was set so that the saw would run too lean, but Stihl has addressed those issues with newer controllers.
Mtronic is electronically simple, but dependant on lots of mechanical things to work properly. A leaking inlet needle in the throttle body will cause the same problems on an Mtronic saw as on a standard carbureted saw. Crappy fuel still doesn't burn well in an Mtronic saw. Water doesn't burn at all. Look at all the simple, normal reasons for a particular issue before jumping to the possibly erroneous conclusion that Mtronic is to blame. My time is valuable, and so too is yours- why waste it guessing. Approach a problem with a systematic plan and rule out problems rather that rule them in. Think about that for a few seconds. Those few seconds of thought may save you hours of frustration,


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## newforest (Jan 14, 2017)

Thanks doc.


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## OpenCanopyTree (Jan 15, 2017)

Stihldoc said:


> I've been a Stihl tech for 34 years. I came into the industry when 031's and 056's were the hot saws. Been there, done that. Mtronic is an excellent engine management system within the limits of its capabilities. What nobody here has addressed is the original issue "the engine runs too fast at idle". Let's put Mtronic aside for a few moments and think about how a competent tech would approach this problem on a non Mtronic saw.
> Stihl has a wonderful diagnostic flow chart called "Stihl engine checklist" or something like that. Its simple, but long. Most techs don't bother with it until all their guessing leads them nowhere in solving a problem. I use it when the answer isn't quick and obvious, and it has never let me down. Again. we're pretending this is a standard carbureted saw with a high idle. Most likely, we'd all try adjusting the idle speed screw to correct the problem. I would. But what if that didn't work? Then it gets interesting. We need to systematically look at all aspects of the saw to determine the problem. The diagnostic chart will take us through the fuel system, controls, ignition, exhaust, etc. Lets say that all these items turn out to be ok. The test that will probably be most telling is a pressure and vacuum test of the crankcase. Even a small air leak will cause a saw to run erratically or not at all. High idle could easily be explained by a leak at a gasket, seal, impulse line, or intake boot. If there's a leak, fix it and re-test the crankcase. Now yo can properly set the mixtures and RPM so the saw will run properly.
> Now lets go back to an Mtronic saw. Everything thats critical for a carbureted saw to run properly ALSO APPLIES to Mtronic. If you have an obstructed fuel filter or a crankcase air leak, that Mtronic saw won't work properly. Its critical to be sure there are no mechanical problems prior to blaming Mtronic.
> Has anyone checked the mechanical parts of this saw, or did they just skip all that because "they knew" its an Mtronic problem???? Mtronic isn't perfect, but it is a simple, generally solid system. What it can't do is magically retune a saw that has an air leak or other mechanical problem. Once all mechanical possibilities are ruled out, only then does a competent tech look at the engine management system.
> ...



Thanks for the detailed breakdown. The shop was unable to diagnose the issue on their own. Hopefully they followed the flow chart and eliminated all other potential fail points before pointing the finger at m-tronic. They told me they did. Where we are at now, is at suggestion from another forum member to swap out the solenoid and see if that fixes the issue. 


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## OpenCanopyTree (Jan 15, 2017)

Khntr85 said:


> You need to tell someone about that dumbass dealer, if he had your saw and you depend on it for a living, my friend you are a VERY patient man!!!!!
> 
> 
> He should have told you he has no clue orngave you another saw!!!!!
> ...



Oh you can bet their name is as good as ****. They know that saw is my main *****, and could not even offer me a loaner. When I dropped it off, I asked if they were fluent in M-Tronic and was assured their tech could handle anything. Fed another load of ******** from a shop just looking to make a buck. I've contacted the district manager for Stihl, and am hoping he'll be able to either light a fire under their asses or get me going with something else. 


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## Stihldoc (Jan 16, 2017)

Arrrgh!
Parts changers.... Darwin said inferior species would die out, but he's wrong about these "geniuses". They are the Zombies of the repair world.
Solenoid valves are easy to test even if you don't have Stihl Diagnostic Software (SDS) on your computer. A solenoid valve is cheap and easy to replace, but wouldn't it be nice to be able to test it without even removing the carburetor? Well, here's how I do it if I suspect a leaking solenoid valve.
I bought a 2xAA battery holder from Ebay. I got a Stihl wiring harness adaptor that plugs into the diagnostic port (sorry, I don't remember the part number, but it was about $8.00). Connect them together- polarity doesn't matter, and install 2 good batteries. Drain the fuel from the saw and remove the fuel filter from the fuel hose. Plug the battery pack into the saw's diagnostic port. Stihl used to recommend a 9V battery for this, but it occasionally fried controllers. Connect your vacuum/pressure pump to the fuel hose and pressurize it to about 5 PSI (.4 bar). The pressure reading should remain constant. This tells you that the solenoid valve is holding against the fuel pressure.
Next, you need to determine if its opening when it needs to. Get a 4" piece of 0.080" string trimmer line and bend an "L" shape at one end. The bent section should be about 1/3" long. heat the bend with a lighter to keep it bent when it cools. Now, poke this piece of trimmer line into the compensation port behind the air filter to depress the metering diaphragm in the carb. Watch the pressure gauge when you do this- it should drop as the solenoid valve opens and passes fuel. Remove the trimmer line and be sure it still holds pressure. 
This quick test takes me about a minute to do and is a great way to confirm that the SDS is really telling me the truth. Mtronic isn't "rocket surgery" as a friend in NH calls it. This stuff is really simple and we need to adapt and learn. Otherwise, the bus leaves without us.


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## CR888 (Jan 17, 2017)

Everytime Stihldoc opens his mouth really good info falls out. A couple of good posts that debug the myth that MT systems were not designed by witches attempting to cause us pain.


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## Conquistador3 (Jan 17, 2017)

CR888 said:


> Everytime Stihldoc opens his mouth really good info falls out. A couple of good posts that debug the myth that MT systems were not designed by witches attempting to cause us pain.



I am pretty sure I've smelled sulfur and heard somebody saying "Hail Satan!" in a muffled voice in the room where I keep my MS362CM.


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## hedge hog (Jan 17, 2017)

I feel sorry for you guys with out a good and trustworthy dealer that can depend on!


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## HarleyT (Jan 17, 2017)

OpenCanopyTree said:


> Anyone else out there having problems with their M-Tronic carbs?
> My 201 t-c recently started acting up. At idle the chain would still be spinning quite quickly, and nothing I could do would remedy the issue. I brought my saw into the dealership on December 12th, and they still haven't gotten an answer out of Stihl. Pretty inconvenient considering it is my only top handle, and I'm a climber.
> 
> 
> Sent from my iPhone using Tapatalk Pro


What rpm was it at idle? Anyone look at the clutch area?


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## OpenCanopyTree (Jan 20, 2017)

HarleyT said:


> What rpm was it at idle? Anyone look at the clutch area?



I'm not sure the exact rpm. It was high enough that the chain was driven at a steady pace. I took part and cleaned the clutch. Still waiting on the boneheads at the shop to get back to me. 


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## farmer steve (Jan 20, 2017)

Stihldoc said:


> I've been a Stihl tech for 34 years. I came into the industry when 031's and 056's were the hot saws. Been there, done that. Mtronic is an excellent engine management system within the limits of its capabilities. What nobody here has addressed is the original issue "the engine runs too fast at idle". Let's put Mtronic aside for a few moments and think about how a competent tech would approach this problem on a non Mtronic saw.
> Stihl has a wonderful diagnostic flow chart called "Stihl engine checklist" or something like that. Its simple, but long. Most techs don't bother with it until all their guessing leads them nowhere in solving a problem. I use it when the answer isn't quick and obvious, and it has never let me down. Again. we're pretending this is a standard carbureted saw with a high idle. Most likely, we'd all try adjusting the idle speed screw to correct the problem. I would. But what if that didn't work? Then it gets interesting. We need to systematically look at all aspects of the saw to determine the problem. The diagnostic chart will take us through the fuel system, controls, ignition, exhaust, etc. Lets say that all these items turn out to be ok. The test that will probably be most telling is a pressure and vacuum test of the crankcase. Even a small air leak will cause a saw to run erratically or not at all. High idle could easily be explained by a leak at a gasket, seal, impulse line, or intake boot. If there's a leak, fix it and re-test the crankcase. Now yo can properly set the mixtures and RPM so the saw will run properly.
> Now lets go back to an Mtronic saw. Everything thats critical for a carbureted saw to run properly ALSO APPLIES to Mtronic. If you have an obstructed fuel filter or a crankcase air leak, that Mtronic saw won't work properly. Its critical to be sure there are no mechanical problems prior to blaming Mtronic.
> Has anyone checked the mechanical parts of this saw, or did they just skip all that because "they knew" its an Mtronic problem???? Mtronic isn't perfect, but it is a simple, generally solid system. What it can't do is magically retune a saw that has an air leak or other mechanical problem. Once all mechanical possibilities are ruled out, only then does a competent tech look at the engine management system.
> ...


thanks @Stihldoc. just bought a 241 and hated to think i might have to take it back to the shop if i had problems. i can hear it now when i tell the wife i'm taking the laptop to the shop to work on a saw. think i'll stick to the 056 that has me confused with all the different changes in parts etc. 
OP sorry for the derail. hoping you get your saw back with a good outcome.


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## Derrick Sawyer (Jan 21, 2017)

Agree with Brad and Doc here. First i always have an extra solenoid on hand since they are cheap and easy to replace. If recalibrate doesn't work, careful inspection of impulse and fuel lines. Vac and pressure next, which unfortunately is more of a pain for a 201T since the regular adaptors don't fit, but you can rig up something. Gorilla tape helps me, two layers on the intake manifold tube can hold vacuum and test thru impulse, move piston up and down slowly should still hold


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## OpenCanopyTree (Jan 25, 2017)

Derrick Sawyer said:


> Agree with Brad and Doc here. First i always have an extra solenoid on hand since they are cheap and easy to replace. If recalibrate doesn't work, careful inspection of impulse and fuel lines. Vac and pressure next, which unfortunately is more of a pain for a 201T since the regular adaptors don't fit, but you can rig up something. Gorilla tape helps me, two layers on the intake manifold tube can hold vacuum and test thru impulse, move piston up and down slowly should still hold



Just picked up the saw with no improvement. They replaced the carb, and got Stihl to warranty it as the saw was under a year old. I looked over the techs notes, and it looks like he tried everything but the impulse line. Because they were not set up with a computer to work on the saw, could it be that the new carb has not been recalibrated and it is running with the old settings?


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## Derrick Sawyer (Jan 25, 2017)

This procedure from a previous post worked for my Stihl 661cm after it was rebuilt, could help in your case, hopefully wont make it worse:
Take the bar and chain off, crank saw in choke position, and leave it on choke running for approx. 90 sec. Do not hit throttle. Then manually move mastercontrol lever all the way to off. Reinstall bar and chain and go make several full cuts.


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## hedge hog (Jan 25, 2017)

I second
But On my 441 you have too touch the throttle to unlock the chock to get it too the off position 

Seamed to recalibrate fine 



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## OpenCanopyTree (Jan 27, 2017)

hedge hog said:


> I second
> But On my 441 you have too touch the throttle to unlock the chock to get it too the off position
> 
> Seamed to recalibrate fine
> ...



Thanks to everyone who chimed in. I brought it to a different shop who had the software to plug into and recalibrate the new carb. Saw is running fine now! 
Lesson to take from this experience is; make SURE you're shop is qualified to work on whatever it is you're bringing them. 


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## E350 (May 22, 2017)

*OpenCanopyTree*: How is your M-Tronic 201T C-M doing? Now that it has been some time, if you were to choose between a Husqvarna 543xp (non-Autotune) and a Stihl MS241 C-M which would you choose?


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## SawRus (Aug 10, 2018)

I have an MS 241 that is in its third Summer. It ran GREAT for two years, has about 90 hours on it, but has started having all sorts of issues the past 2-3 months.
It is now hard to start taking about 8-10 pulls when cold, and as many or more when hot. If it does come to life it is almost impossible to get it to accelerate off idle about 50% of the time. Dies frequently when at idle as well, even after it "knows" where it is at, sometimes will die when throttle chopped. If you put it down to move branches or logs it will die quite often now as well. Just started dying when in the middle of a cut as well.
I went through the carb, clean as a whistle, replaced the solenoid once, re-calibrated, no change. The dealer changed out the solenoid too, and he also replaced the diaphragm in the carb, re-calibrated it as well, still no change.
Seems to be some sort of altitude sickness as this always happens when up about 7000 feet or higher, and worse if temperatures are high (anywhere above eighty) . Yesterday I went out in the afternoon when the temp was 95 and started it up here in my backyard. Two pulls to get it started, two more till it was acclimated. I am at just over 5000 feet. It runs like a champ with no issues at all at this altitude. Dealer agrees as he had no issues after he worked it over and thought it was cured.
Both dealer and I are stumped. Any ideas?


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