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Are M-Tronic & AutoTune holding up?

Discussion in 'Chainsaw' started by MaddBomber, Sep 10, 2019.

  1. gary courtney

    gary courtney eeny meeny miny moe

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  2. jltrent

    jltrent ArboristSite Operative

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    From what I hear most around here have had pretty good luck except for the high dealer repair cost associated with them and they sure do grumble about that. Maybe they are helping save our planet because it sure has been hot the last few days.
     
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  3. Brent Nowell

    Brent Nowell ArboristSite Guru

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    I’m sorry but you are mistaken
     
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  4. lone wolf

    lone wolf MS 200T King

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  5. foeke

    foeke ArboristSite Operative

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    I don't think he is.
    The gas cools the engine by evaporating.
    The oil doesn't.
    The more oil, the less cooling per liter.
    That's why you need to run a tad richer when using more oil.

    Verstuurd vanaf mijn SM-G955F met Tapatalk
     
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  6. Duce

    Duce Addicted to ArboristSite

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    No he is correct, a oil molecule is larger than a gas molecule. If less small molecules can pass through a jet, because of being blocked by larger oil molecules you are running at a leaner condition. People who put oil in their gas in snowmobiles because of cold weather have proven this over and over with engine seizures. Me being one of them.

    His question about running AT's running leaner and manual tuning is better, how many of them can re-tune a running, cutting saw over 20 times a second. He is welcome to come run my auto-tunes, 550,562 ported, 572 and can get a 540 for him to run and all 4 stroke coming out of the cut. It's a sweet sound!
     
  7. weimedog

    weimedog Addicted to ArboristSite

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    Oil is a fuel as well. Auto tune Husqvarna's "real time" tune. Never stop tuning at full or mostly full throttle applications. Always shooting for peak RPM's regardless of oil / fuel mixtures using a simple "lean out" test strategy.....if when fuel is restricted for a measured & short period of time (a few RPM's) does the saw pick up or lose RPM's...then adjust the mixture baseline accordingly. Fuel delivery is effected by the time a "solenoid" valve stays open as it cycles. Basically this is a non issue from a "tuning" perspective. Issues to be more concerned about are related to the lubricity and burn characteristics of oils, and that is a huge discussion in of itself. Of "mechanical" parts such as throttle position sensor, solenoid operated valves, and other Carb parts; I guess as with ANY carburetor, those carb's are susceptible to the same issues relative to contaminated or some other situation that is a result of sub standard fuels.
     
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  8. grizz55chev

    grizz55chev Tree Freak

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    OIL THREAD!:eek::crazy2:
     
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  9. holeycow

    holeycow Addicted to ArboristSite

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    SASQUATCH THREAD!! :crazy2:

    oops, wrong thread.
     
  10. Huskvarna hotellgäst

    Huskvarna hotellgäst ArboristSite Operative

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    Maybe so. In another 5 years at 200,000km it may be more economical to replace rather than repair. In that case it will have more than fulfilled both it's manufacturer's and its owner's expectations.

    Like a car, a new model chainsaw is designed and manufactured
    (a) to exceed the performance and reliability of the model it replaces while costing less to produce,
    (b) to meet or exceed the expectations of the buyer,
    (c) to satisfy the requirements of regulators.
    So while it's important to ask and consider questions about the performance and reliability of new techniques such as AutoTune/M-Tronic (I remember people being uneasy about electronic ignitions in chainsaws because you couldn't fix it in the bush by cleaning and adjusting the points), it's unrealistic to expect manufacturers to keep making cars, bikes or saws "just like they used to".
     
  11. SawTroll

    SawTroll Information Collector

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    Where is GARY???
     
  12. Brent Nowell

    Brent Nowell ArboristSite Guru

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    It ain’t that bad, is it? Lol
     
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  13. Cycledude

    Cycledude ArboristSite Operative

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    Just don’t understand why so many members refuse to use the oil ratio recommended by the manufacturer .
     
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  14. andy at clover

    andy at clover Woods!

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    I’m liking m-tronic a lot.
    Where is the big displacement at saw for milling?
    Sick of tuning milling the saw. Pia!

    Tried 661... not big enough.
     
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  15. catbuster

    catbuster Catskinner. And buster.

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    Well... The group think here is there’s an EPA conspiracy to end all chainsaws. So, obviously, mixing more fuel in with their oil, where the fuel, being fuel, burns putting off more carbon and VOCs into the atmosphere, is why they go with more oil than what the manufacturer suggests.

    It could never be that newer oils lubricate better so less is needed, and heaven forbid the people who design the equipment know what they’re doing.:angry:
     
  16. weimedog

    weimedog Addicted to ArboristSite

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    New oils is a concept like "new" math education. There is a point where manufacturing processes, math, physics & chemistry define the limitations and new oils blends derived from some base stock are really a marketing ploy...like common core is a new & improved education scheme...wait...did that new math and then common core move things forward?? Did "math" and the things math as a language attempts to described really change? Common core.....50:1 conventional wisdom and all that crap. Fancy colors on bottles making a new product.....had a wonderful discussion years back with a Mobil Engineer. But realize it makes No sense in going through the reasons why.....again. and again I mix as I do. Folks will do as thy believe. There will be some who are independent thinkers choosing to move some parameter one way or another for a variety of reasons important to them and some that will happily be a part of the borg. :) Either way saws will run and trees/firewood will be cut. Folks will be happy as most of the suggested ratio's are good enough. ( Assuming a good gasoline, and consistent oil quality. )
     
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  17. drf255

    drf255 BAD CAD

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    A saw is lubricated by oil that falls out of suspension from the atomized charge.

    The OEM must meet EPA requirements and hence the oil ratio’s have increased over the years.

    Ever see some of the metal tags on old homelites? Many called for a pint of 30W per gallon of gas, or 8:1.

    Sure, oils have evolved over the years, so 8:1 is ridiculous. Power tests have revealed that 32:1 generally makes the most power and keeps the saw safe. @blsnelling ?

    The reason that the AT saws lean out with more oil is a KISS reason, the mix simply is too viscous to flow through the jet at max opening, so the AT system can’t control the rpm by increasing fuel flow. It can limit free spool rpm by the coil, but not in-the-cut rpm.

    When the system senses that it’s not richening the saw appropriately, odd stuff starts to happen. It’s very hard to believe, but it’s true.

    I’ll try to post a video of what too thick of a mix will make a Stihl 261 do. I run my regular saws on Motul800 at 32:1 without issue. It’s a thick and very viscous oil. Switching to Saber at 40:1 made the same saw run perfectly without any changes.
     
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  18. drf255

    drf255 BAD CAD

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    Same saw. It’s ported.

    Go to 0:30. That’s when the saw gets hot.



    Go to 2:45. It gets hot. Dies in the cut. You can see me holding full throttle with no chain movement.



    And here it is with nothing but the mix changed



    Do you believe me now?

    BTW, the piston was starting to streak with the thicker mix.

    @huskihl
     
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  19. weimedog

    weimedog Addicted to ArboristSite

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    Nope vs. a generalization, the situation might be unique to your saw/oil set. Guess I won't be buying either that saw or the oil.

    The assumption being that the flow is restricted by the diameter of the jets & the capability of those jets isn't enough at full rich to flow enough fuel for the saw to run properly with a heavier oil mix. That concept applied to Husqvarna's; the jets, assuming the valve is open all the time; would still create a lean condition with AT at FULL rich with a heavier oil mix. IF that were true I would see that in the operating history numbers when I look at CST. But I don't. I might see a 4 or 5 point change in the CST operating history and BTW this is something I have checked for. IF the saw was leaning out to the point the RPM's were dropping, I would see the numbers drop as Autotune tries to compensate....I haven't seen that with the fuel mixed and oils I have used. SO

    Three possibilities:
    1) The oil you use has different properties as compared to the old Synthetic "Blend" I use ( The Husqvarna XP, NOT the new stuff....yet ). This brings up a whole set of issues related to the base stock these oils are derived from.
    2) Stihl's implementation of that technology was not done well...which I highly doubt..
    3) What you are seeing is an anomaly , that sample of one where other factors may have interfered in your finding.
     
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  20. drf255

    drf255 BAD CAD

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