MS201TC And Other M-Tronic Problems?

[Mastermind]

I ported a MS201TC for a customer in 2021....and it was good for him over several years. Then....it began to idle too high. The saw was equipped with a black solenoid, with a build date of 2019. Which means it was an M1 system. His local dealer replaced the solenoid with a green one....and the issue persisted. So...he sent it to us. First we vacuum and pressure tested....which it passed with flying colors. Checked to be sure that the carb was closing properly....and it was. The saw would not continue to run through a reset.....so we figured that it was the solenoid. I tried a new black solenoid, a new green one, and a new white one. No matter which one we used, the saw wouldn't complete the reset procedure. At this point I decided to shoot the parts cannon at it. I tore down a new 201 and tried a new carb with a white solenoid. No change. Then I swapped the coil. The saw ran as a new saw. Used the M3 reset....and it passed. Then I reinstalled the old carb....but with a new white solenoid. Passed the reset again. Took it to the woods and ran a tank of fuel thru it....no high idle.

You fellas that work on M-Tronic saw regularly....chime in here with your weird experiences. I'd like to create this thread both as a troubleshooting resource, and just a place to vent about the silly things we see.

 

[Woodwackr]

So, a bad coil on that one.

 

[Mastermind]

So, a bad coil on that one.

Yeppers.

 

[hacskaroly]

Yup, saws in trees are not for me...

 

[redlight066]

I ported a MS201TC for a customer in 2021....and it was good for him over several years. Then....it began to idle too high. The saw was equipped with a black solenoid, with a build date of 2019. Which means it was an M1 system. His local dealer replaced the solenoid with a green one....and the issue persisted. So...he sent it to us. First we vacuum and pressure tested....which it passed with flying colors. Checked to be sure that the carb was closing properly....and it was. The saw would not continue to run through a reset.....so we figured that it was the solenoid. I tried a new black solenoid, a new green one, and a new white one. No matter which one we used, the saw wouldn't complete the reset procedure. At this point I decided to shoot the parts cannon at it. I tore down a new 201 and tried a new carb with a white solenoid. No change. Then I swapped the coil. The saw ran as a new saw. Used the M3 reset....and it passed. Then I reinstalled the old carb....but with a new white solenoid. Passed the reset again. Took it to the woods and ran a tank of fuel thru it....no high idle.

You fellas that work on M-Tronic saw regularly....chime in here with your weird experiences. I'd like to create this thread both as a troubleshooting resource, and just a place to vent about the silly things we see.

View attachment 454175

I did this video a few years ago when the black solenoids were discontinued but still available online and documented everything. The video is a little lengthy but done as fast as I could in real time. Nowadays if you’ve got a 201tc with a coil that’s still V1, upgrading to V3 on the coil and white/grey solenoid is about the only option.

 

[redlight066]

As stated in the video, I had a brand new 362 MTronic last fall that had a defective white solenoid. First bad one I’ve seen, new or old, and I work on this stuff everyday. I swapped out each piece of the MTronic system one piece at a time, in sequence from the coil to the throttle position sensor. I skipped the solenoid because they don’t fail. Lol.

There must have been a flaw in the carb body on this particular saw.

 

[redlight066]

Randy, this is a great idea. If I find any other strange issues I've had with MTronic I'll add them here.

 

[stretch5881]

I just had a MS261C 3.0 that ran like crap and would not reset. It turned out that the center electrode in the spark plug was loose. The next strange thing was that the spark plug boot fell off. The terminal in the end of the coil wire was broken. I was going to blame the electronics, but I would be wrong.

 

[Duane(Pa)]

I don’t have anything to add, but I want to subscribe to this thread. One thing that strikes me, is we are all chainsaw nerds and want to try and figure these things out. I really wonder how this electronic stuff is going to go for the masses that just want to “pull the rope” and cut wood… Some dealers have very low aptitude and ability to troubleshoot.
Can you say battery saw?

 

[hacskaroly]

I really wonder how this is going to go for the masses that want to “pull the rope” and cut wood…

Many just buy another saw...if they had Stihl, then they want Husky because Stihl is crap, if they had Husky, then they want Stihl because Husky is crap...

Many around here think battery saws are for girls...

 

[Mastermind]

Randy, this is a great idea. If I find any other strange issues I've had with MTronic I'll add them here.

Thanks for sharing Rich. Hopefully we can all get some use from the thread.

 

[Mastermind]

I just had a MS261C 3.0 that ran like crap and would not reset. It turned out that the center electrode in the spark plug was loose. The next strange thing was that the spark plug boot fell off. The terminal in the end of the coil wire was broken. I was going to blame the electronics, but I would be wrong.

I've seen that a couple of times now. Spark plugs sure ain't made like they were.

 

[Mastermind]

I don’t have anything to add, but I want to subscribe to this thread. One thing that strikes me is we are all chainsaw nerds and want to figure things out. I really wonder how this is going to go for the masses that want to “pull the rope” and cut wood…
Can you say battery saw?

I have turned a few folks onto battery saws. They ain't bad to be honest.

 

[cuinrearview]

I just had a MS261C 3.0 that ran like crap and would not reset. It turned out that the center electrode in the spark plug was loose. The next strange thing was that the spark plug boot fell off. The terminal in the end of the coil wire was broken. I was going to blame the electronics, but I would be wrong.

I've seen that a couple of times now. Spark plugs sure ain't made like they were.

Try Denso fellas. W22MPR-U

 

[Duane(Pa)]

Try Denso fellas. W22MPR-U

Where is a good place to purchase? Shirt, sometimes I can’t find a dang rim sprocket…

 

[cuinrearview]

Where is a good place to purchase? Shirt, sometimes I can’t find a dang rim sprocket…

If you're just getting a few for your woods bag, try the Google. If you need quantity, find a hammer donkey that works for the company. Rumor has it he has brought a bunch to a GTG that used to happen on the side of a beautiful hill in PA. Among others.

 

[Mastermind]

Try Denso fellas. W22MPR-U

What is the 10mm version?

 

[cuinrearview]

What is the 10mm version?

There isn't one. I keep checking. The plugs are made in Jay-pan so I can't just walk up to R&D and ask when TF they're coming.

 

[oddsawz]

Doesn’t the coil version have to match the solenoid version? I’ve only worked on a 661c and the ‘Kit’ contained the coil, solenoid and fuel filter.

 

[Mastermind]

Doesn’t the coil version have to match the solenoid version? I’ve only worked on a 661c and the ‘Kit’ contained the coil, solenoid and fuel filter.

Yes. The older saws used a black solenoid. The green was an "upgraded" version that was supposed to work with that coil as well. When I used the new coil, I also used the white solenoid and the orange fuel filter.