Stihl M-tronic technology-is it worth it

[PapaWhitebeard]

Just make a note of the tune setting (Hi/Lo) on the saws when you change altitudes. And don't forget when going back to sea level to retune, or you'll have a lean condition.

I do this with mix too. Sometimes I run 100LL in my mix and the tune is a bit different than with non-E10 pump gas. If you keep notes it's 30 seconds with a screw driver.

Yep for sure. But that stuff is so minor compared to rejetting. My sea level place is in California where the only gas you can buy outside of a racetrack is ethanol mix and my high altitude places are in Utah where I can buy non-ethanol gas. So in both cases I always run the calibration function. But again… so so so simple and easy and fast compared to re-jetting the carb.

 

[bwalker]

At this point I greatly prefer Mtronic/Autotune over a traditional carb. I can tune a carb very well, but I don't care to do it anymore. Most guys can't tune a carb to save their lives, so it's a great benefit.

 

[bwalker]

Yep for sure. But that stuff is so minor compared to rejetting. My sea level place is in California where the only gas you can buy outside of a racetrack is ethanol mix and my high altitude places are in Utah where I can buy non-ethanol gas. So in both cases I always run the calibration function. But again… so so so simple and easy and fast compared to re-jetting the carb.

I think you will find that you don't need to run the calibration function. I haven't done it with autotune yet, but with Mtronic I have cut up near 9000 feet and 60 degrees and then the next day at 2000 feet and 90 degrees. I have also ran the saw in 9 degree weather then put it away for the season. Next time I pulled it out it was nearly 100 degrees. Mtronic never missed a beat in either case.

 

[PapaWhitebeard]

I think you will find that you don't need to run the calibration function. I haven't done it with autotune yet, but with Mtronic I have cut up near 9000 feet and 60 degrees and then the next day at 2000 feet and 90 degrees. I have also ran the saw in 9 degree weather then put it away for the season. Next time I pulled it out it was nearly 100 degrees. Mtronic never missed a beat in either case.

That’s good to know. All I know is my KTM 125 will barely run if I jet it 5,000 ft up in the mountains at 8-9k altitude unless I rejet it. So yeah probably the saw would run but (shrug) the recalibration function and high altitude mode is ~60 seconds of my life… no swapping jets required. So…. easy.

And if I jet my 125 for 70 degrees F sea level the bike just straight up won’t run at 9k feet >90 degrees F..

But next time I take saws from CA to UT I’ll try just just running them because I’m curious. Like you said… the mtronic self adjust function is pretty impressive

 

[PapaWhitebeard]

And I love my mtronic… the only reason I stand by preferring carb only if I didn’t move between altitudes is the same reason I don’t like depending on cell phones and the interweb… if there’s some disaster… (shrug) idk like idk Katrina style disaster or whatever in 10 years and I need a computer to repair fuel injection or Mtronic and I don’t have one… well… that would suck. In the meantime, every single one of my vehicles made before 1973 I can fix with hand tools in my shop… no matter what.

Paranoid? Maybe I am.
Hypocrite? Maybe I’m that too because even though half my bikes are carbureted I won’t buy another motorcycle without fuel injection on it from now on… because like you said… even though I have yet to find a carburetor I can’t tune… I sure like knowing my KTM 450 will absolutely scream whether I’m in Cabo San Lucas in triple digit heat farenheight or 55 f weather in Heber County, Utah at ~8500 feet. No tuning or touching required… all I have to do is RIDE

 

[sean donato]

As the pandemic taught us, it didn't matter what you ran, you couldn't get parts period. Didn't matter if it had a carb or extra seliniod hanging off the carb. Zero parts available, heck you were lucky enough to find a pro saw in stock at the time. Really the last thing I'm worried about if the shtf.

 

[bwalker]

That’s good to know. All I know is my KTM 125 will barely run if I jet it 5,000 ft up in the mountains at 8-9k altitude unless I rejet it. So yeah probably the saw would run but (shrug) the recalibration function and high altitude mode is ~60 seconds of my life… no swapping jets required. So…. easy.

And if I jet my 125 for 70 degrees F sea level the bike just straight up won’t run at 9k feet >90 degrees F..

But next time I take saws from CA to UT I’ll try just just running them because I’m curious. Like you said… the mtronic self adjust function is pretty impressive

When you get to strokes that are in a high state of tune like a 125cc dirtbike they become very sensitive to carb tuning.
That's why I preferred 500cc bikes followed by 250's. A CR500 can be 4 main jet sizes rich and still pulls like a tractor.

 

[PapaWhitebeard]

When you get to strokes that are in a high state of tune like a 125cc dirtbike they become very sensitive to carb tuning.
That's why I preferred 500cc bikes followed by 250's. A CR500 can be 4 main jet sizes rich and still pulls like a tractor.

For sure. And yeah I tune my 125 to scream… (shrug) because it’s a 125