Are M-Tronic & AutoTune holding up?

[weimedog]

About the only thing you proved with that is not to use Motul800 in Stihls modified as your saw has been. You might want to start researching the properties of Motul vs. the Sabre. Bean oil? Ester based? What. Paraffin based? Do changes in compression and/or timing effect this? OR just use the Sabre on your saw build and let the engineers figure it out. BTW a case to be careful when either buying or building to some random saw modification where compression has been increased and timing advanced. There is a huge difference in fuels/oils and pushing the limits mechanically will change fuel requirements. Something not really talked about. Why the factories have to recommend to the worse case scenario. And more power equals more heat. How many of these back yard engineered builds adds cooling to the mix? Push the compression and the timing numbers and heat will be a byproduct. In a long cut, heat build up can cause similar symptoms including loss of power & accelerated wear on the pistons. More oil is more energy, one of the reasons some use the heavier mixes. What happens in these threads is that sample of one situation, is supposed to define and clarify ALL situations without a true understanding of all the factors involved.

 

[weimedog]

One last thing, to take what your premise is literally, you are saying Stihl's fuel delivery system is inadequate to handle any more fuel flow requirements than the slightly modified Stihl ms261 demands. A jet. That's NOT Autotune. Autotunes are simply a control interface wrapped around a carburetor. All the physics of carburetor's still apply. You say that Motul mix works in your normal saws. SO obviously it isn't about the mix in a general sense. It's about that saw.

AND as is typical, you would like to expand that situation to ensnare and encompass ALL autotune saws. wow.

( As a reference, My modded by back yard engineering by me 562 is a 2015 version with an el46. Prior to the compression, muffler, and porting changes it lived with CST numbers at around 60-70 both High & low speed, after mods it runs in the 50-60 range on the high speed and 30-40 on the low (muffler mod), same fuel. Point? Mods did effect the fuel mixture requirements. But no where near the limits of the system. If those numbers dropped into single digits, I would start researching as to why. Those "numbers" are undefined units giving a reference as to how long the "solenoid" is holding closed a valve for fuel supply. Lower is closed for a shorter period of time or open longer, higher open for a shorter period of time. I've kept track over the last three years to see how specific mods & fuel mixes effect fuel requirements on those 562's using the Husqvarna Autotune/ CST as a tool. )

 

[SawTroll]

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.

A good exemple is that Jonsereds saws from the 1970s, that were supposed to be run at 25:1 back then, are not harmed at all by running 50:1 premixed Aspen fuel (or similar) in them. This is about Alkylate fuel and fully synthetic oil - I wouldn't do it (50:1) with pump gas and dino oil.

 

[CR888]

I find it funny everyone thinks all oils are the same at a given ratio....there simply not. Their viscosity varies between brands/types. For example running Motul 800t at say 50:1 could well be a lot more oil than running Saber at 40:1. Every oil is different and what ratio that will best suit your application will vary. I would expect running Motul off road 2T oil @32:1 will give you engine behavioural issues...its most likely far to much oil for your needs. Until some of these things are comprehended, folks will continue to blame AT/MT systems for their misuse or lack of understanding of oil and how it differs.

 

[foeke]

I think we can be proud of ourselves.

More than 40 post in, and it still didn't spiral in an oil thread. A couple of post could have sparked that spiral, but we as an community have persevered!
Great job since it is an interesting read so far

Verstuurd vanaf mijn SM-G955F met Tapatalk

 

[Deleted member 117362]

I do not care what anyone thinks, run all my 2 stroke, blower, line trimmer and chainsaws on Husqvarna or Dolmar synthetic or semi-synthetic with stabilizer mixed 40:1 using rec fuel. Have not destroyed anything yet and will continue to do so. So There!

 

[Brent Nowell]

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

You do realize that it is not the manufacturer that recommends 50:1 it’s the EPA technically. The manufacturer has no choice but to recommend an oil ratio that suits the EPAs goals and not the goals of engine longevity.

 

[drf255]

Rough crowd here, as usual.

Passionate people.

Do as y'all please by all means.

 

[Derf]

Rough crowd here, as usual.

Passionate people.

Do as y'all please by all means.

Some things never change

 

[drf255]

One last thing, to take what your premise is literally, you are saying Stihl's fuel delivery system is inadequate to handle any more fuel flow requirements than the slightly modified Stihl ms261 demands. A jet. That's NOT Autotune. Autotunes are simply a control interface wrapped around a carburetor. All the physics of carburetor's still apply. You say that Motul mix works in your normal saws. SO obviously it isn't about the mix in a general sense. It's about that saw.

AND as is typical, you would like to expand that situation to ensnare and encompass ALL autotune saws. wow.

( As a reference, My modded by back yard engineering by me 562 is a 2015 version with an el46. Prior to the compression, muffler, and porting changes it lived with CST numbers at around 60-70 both High & low speed, after mods it runs in the 50-60 range on the high speed and 30-40 on the low (muffler mod), same fuel. Point? Mods did effect the fuel mixture requirements. But no where near the limits of the system. If those numbers dropped into single digits, I would start researching as to why. Those "numbers" are undefined units giving a reference as to how long the "solenoid" is holding closed a valve for fuel supply. Lower is closed for a shorter period of time or open longer, higher open for a shorter period of time. I've kept track over the last three years to see how specific mods & fuel mixes effect fuel requirements on those 562's using the Husqvarna Autotune/ CST as a tool. )

Did you read my first post in the thread (#19)

I did mention viscosity. Motul800 is one of the thickest 2T oils, so is H1R. Another oil may work fine at 32:1, I never said it wouldn’t. When I couldn’t figure out my issue, I actually did research it. It has to do with thickness of mix (as I also stated).

You generalized it.

Simply stating that they are more finicky with different oils and ratios of them. That’s really it. A guy that uses the same mix as his other saws MAY have an issue.

MY MODIFIED 261 STIHL’S DONT RUN CORRECTLY ON 32:1 MOTUL800 MIXTURE.

Is that better Walt?

 

[farmer steve]

I read threads like this because i have 2 M-tronic saws (241/462) to see if /what issuses are going on and i respect you guys opinions that do the tests and analyze stuff. I started out with a brand new 023 back in the 90's and ran 50:1 because that's what the Stihl manual said and i didn't have youse guys to tell me any different . I was sawing 20 or more cords a year every year and had no issues with the saw. I then bought a new 290, yep 50:1. then bought a 250 more 50:1. All the saws were run stock no mods of any kind. I'd probably stihl be running just those 3 saws but you all know about CAD. I started running 45:1 back around 2013. That's the year i joined a chainsaw forum.

 

[weimedog]

Did you read my first post in the thread (#19)

I did mention viscosity. Motul800 is one of the thickest 2T oils, so is H1R. Another oil may work fine at 32:1, I never said it wouldn’t. When I couldn’t figure out my issue, I actually did research it. It has to do with thickness of mix (as I also stated).

You generalized it.

Simply stating that they are more finicky with different oils and ratios of them. That’s really it. A guy that uses the same mix as his other saws MAY have an issue.

MY MODIFIED 261 STIHL’S DONT RUN CORRECTLY ON 32:1 MOTUL800 MIXTURE.

Is that better Walt?

Yup

Your original supposition was:
" 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."

My issue is the words:
" The reason that the AT saws lean out with more oil is a KISS reason", where "AT saws", a plural; now what ever follows is cast to all AT's as a set or synthetics at 32:1 depending on how this is interpreted, and one thing I have learned is many will interpret differently than you intended. You imply your situation, this resultant "lean out" with the possibility of damage, is unique to Autotunes. While that is likely in your situation, that's not the only possibility and the "viscosity" would apply to any system from AT through conventional carbs to Fuel Injection..furthermore I haven't seen big swings in the operation history in CST on my saws with 32:1 vs. 50:1 using Husqvarna's older XP oils. I do recognize that is a SMALL and unique sample and therefore don't read much into it.

My supposition is:

Is based on your post there are two area's that may ( key word is "may" ) be "on the edge" with that saw, Cooling and /or fuel delivery system. That has nothing to do with the generic "Autotune" concept which is just a control system around those components, your "fuel flow" premise has to do with the size of the components controlled. All Autotune's aren't created equal. All builds aren't equal either. I ran out of fuel on tweaked Chinese 660's when I was shooting for RPM's. 372's as well. Having a situation where the "stock" carb limits RPM's and reliability when the fuel usage requirements are increased is very common. Also on air cooled designs having heat related issues when increasing compression & RPM's creating more "heat" than the cooling system is designed to handle. Burning more fuel generates more energy, hopefully more power and definitely more heat. Both can be interrelated as well. But neither related in anyway to the AT concept specifically, simply fuel and the mechanical components are a part of the design of the total "system" of which fuel delivery systems, cooling and fuels are a part. In fact, to the "OP's" question, a properly sized & designed AT system will tune all fuel mixtures to their max potential.

My concern is:
Modus opporendi is observations and analysis like these permeate conversations and even perceptions for years to come, and I don't like generalizations.... Especially those done without a research effort to understand exactly what is happening with that system. Your concept of "thick" oil pushing things over the edge may be true...but who really has the time to drill down on the exact physics of the situation....except the manufacturers who design and build a system to work reliably world wide with all the understood issues. Who out there hacking these saws, especially the newer saws; have the ability to develop them to those OEM level understanding & standards? And pushing physical limits on a build, then having to use fuels to "tweak" the final system is as old as internal combustion engine...why race fuels are sold. Nothing here is an indictment of either 32:1 Mixes with "Synthetics" or Autotune Saws. Just that particular fuel mix on that particular Stihl 261. This is as much a case to keep those saws stock as anything....a red neck might say that saw is "effed up" as it now won't run the mix available... And others might see this as an epiphany on things to try when pushing things like timing, compression, and RPMs, even on Autotunes. But here? Most will see one or two "a-oles" having a pride fight ! (Instead of a conversation) LOL!

 

[newforest]

A lot of fuel injected vehicles are easy to fix. A key tool required is sometimes just a wire brush - clean the ground points and you can be good to go. Other times, the various sensors wear out in various ways, such as the O2 sensor getting so carboned up the system starts running rich. Once you know all the sensors, they are often simple to replace as they are external on the engine.

I continue to puzzle at how folks use the word ‘solenoid’ around M-Tronic saws, I will just say that.


Those with a deep interest in all this would probably enjoy reading this thread on the new Stihl 500i:

https://www.arboristsite.com/community/threads/ms500i-review.331946/

I thought there would be more discussion of that saw by now. A tech recently described it to me like this: “M-Tronic’s days may be done anyway,” referring to the 500i system.

I am still interested in learning expected longevity of AutoTune saws, in terms of hours. I don’t run one all year-round, but sometimes do several months sequentially.

My view is that the fuel economy gains mean I won’t be going back to regular carbs.

 

[Mad Professor]

A lot of fuel injected vehicles are easy to fix. A key tool required is sometimes just a wire brush - clean the ground points and you can be good to go. Other times, the various sensors wear out in various ways, such as the O2 sensor getting so carboned up the system starts running rich. Once you know all the sensors, they are often simple to replace as they are external on the engine.

I continue to puzzle at how folks use the word ‘solenoid’ around M-Tronic saws, I will just say that.


Those with a deep interest in all this would probably enjoy reading this thread on the new Stihl 500i:

https://www.arboristsite.com/community/threads/ms500i-review.331946/

I thought there would be more discussion of that saw by now. A tech recently described it to me like this: “M-Tronic’s days may be done anyway,” referring to the 500i system.

I am still interested in learning expected longevity of AutoTune saws, in terms of hours. I don’t run one all year-round, but sometimes do several months sequentially.

My view is that the fuel economy gains mean I won’t be going back to regular carbs.

Lets see 30-40 years from now. My 028, 038, 056 still run fine.

M-tronics going to be healthy 2050?

 

[weimedog]

A lot of fuel injected vehicles are easy to fix. A key tool required is sometimes just a wire brush - clean the ground points and you can be good to go. Other times, the various sensors wear out in various ways, such as the O2 sensor getting so carboned up the system starts running rich. Once you know all the sensors, they are often simple to replace as they are external on the engine.

I continue to puzzle at how folks use the word ‘solenoid’ around M-Tronic saws, I will just say that.


Those with a deep interest in all this would probably enjoy reading this thread on the new Stihl 500i:

https://www.arboristsite.com/community/threads/ms500i-review.331946/

I thought there would be more discussion of that saw by now. A tech recently described it to me like this: “M-Tronic’s days may be done anyway,” referring to the 500i system.

I am still interested in learning expected longevity of AutoTune saws, in terms of hours. I don’t run one all year-round, but sometimes do several months sequentially.

My view is that the fuel economy gains mean I won’t be going back to regular carbs.

My tweaked 562's, all three; get used during the firewood season & into the winter for a variety of jobs. One gets used as a loaner saw for loggers who have me work on theirs year around. All three are wearing "well" to this point. The first impressions of the new 572 AT's are also very good, but we haven't seen them for a long enough time yet. Nothing has come to light in my limited world as an intrinsic issues as happened on the first 562's and 550's. As far as the AT components themselves (ignition/carb), I have never seen one fail. I have heard of a few over the years that were replaced by dealers I know, usually under warranty, but not at a greater frequency or likelihood of typical CDI ignitions from the same sources...probably a statistical thing. AND I like the ease of starting mine have and as you pointed out the fuel usage. Go back to the 576's, I have seen typical mechanical failures as a saw system in a pro logging situations as any saw would have. Yet again haven't seen or heard of the actual "auto-tune" components fail at a greater rate than the standard ignition components on the non autotune version. While I don't have the viability in my small shop operation of a large dealership. I do take on work from two dealers when I have time. And know a couple of more. No "flags" yet on the actual Husqvarna Autotune carb & ignition components. Some of the new saw designs....that's a different story. But it's a big world out there and I'm sure there are many different experiences.

 

[farmer steve]

Lets see 30-40 years from now. My 028, 038, 056 still run fine.

M-tronics going to be healthy 2050?

I'll let you know in 2050. If I make it to 94.

 

[weimedog]

I continue to puzzle at how folks use the word ‘solenoid’ around M-Tronic saws, I will just say that.


.

I'm not as familiar with the "M-tronic" system.... But here is literally how Husqvarna describes their "valve" and I quote:

" Magnetic (fuel) Valve
The Magnetic valve opens and closes to allow fuel through the carburetor"

 

[Mad Professor]

I'll let you know in 2050. If I make it to 94.

For your sake, I hope stihl still has electronic sensors and such availabile.

I've got enough carb /gasket kits to last until then, less then a trip to get a m-tronic worked on

 

[Mad Professor]

[QUOTE="newforest, post: 6999374, member: 74436"]A lot of fuel injected vehicles are easy to fix. A key tool required is sometimes just a wire brush - clean the ground points and you can be good to go. Other times, the various sensors wear out in various ways, such as the O2 sensor getting so carboned up the system starts running rich. Once you know all the sensors, they are often simple to replace as they are external on the engine.

I continue to puzzle at how folks use the word ‘solenoid’ around M-Tronic saws, I will just say that.


Those with a deep interest in all this would probably enjoy reading this thread on the new Stihl 500i:

https://www.arboristsite.com/community/threads/ms500i-review.331946/

I thought there would be more discussion of that saw by now. A tech recently described it to me like this: “M-Tronic’s days may be done anyway,” referring to the 500i system.

I am still interested in learning expected longevity of AutoTune saws, in terms of hours. I don’t run one all year-round, but sometimes do several months sequentially.

My view is that the fuel economy gains mean I won’t be going back to regular carbs.[/QUOTE]

Yea, fuel pump is in the gas tank. What's that cost to fix?.

My Chevy fuel pump is two bolts and two fuel lines. I can do it side of road, in 1/2 hour, and fuel pump is < 1/5 cost.

Carbs get great fuel mileage, before EPA. You have to take off all crap, set up dist vac advance for high at idle and partial load. Dist mech for full advance under load.

I have a 68 RS/SS, camaro, 370/350 LT1, 4150 holley, curved dist, 3:08 gears. It gets 25 mpg if I don't hit the 4bbl, that is <75mph. It will pull 7000 rpm in 4th with 3:08 gears 275/50/15 tires. Speedo stops at 120mph (still in 3rd) , tach tells me 7000 rpm in 4th is ~160 mph. 1st-3rd in a quarter is ~ 11.0.

I run almost 40 degrees mech dist advance with good 100LL AV gas. 35 or less if at a pump.

Motor was built be me and took > 8 months. My Uncle worked for GE ordinance, he "lent" me all the tools to build, GE got them back. They measured stuff to 0.00000", yes millionths

I also have a heavy half 73 C10 292-6. Stripped of emmisions it gets ~22 mpg. 1-brl rochester carb man/choke, single wire delco dist, 2 1/2" ex, 3:23 posi/16" wheels. Two vac lines, to dist and PVC. I can crawl inside under the hood if I ever need to work on it, even if it raining.

 

[Deleted member 117362]

I have a 68 RS/SS, camaro, 370/350 LT1, 4150 holley, curved dist, 3:08 gears. It gets 25 mpg if I don't hit the 4bbl, that is <75mph. It will pull 7000 rpm in 4th with 3:08 gears 275/50/15 tires. Speedo stops at 120mph (still in 3rd) , tach tells me 7000 rpm in 4th is ~160 mph. 1st-3rd in a quarter is ~ 11.0.

I run almost 40 degrees mech dist advance with good 100LL AV gas. 35 or less if at a pump.

Motor was built be me and took > 8 months. My Uncle worked for GE ordinance, he "lent" me all the tools to build, GE got them back. They measured stuff to 0.00000", yes millionths

I also have a heavy half 73 C10 292-6. Stripped of emmisions it gets ~22 mpg. 1-brl rochester carb man/choke, single wire delco dist, 2 1/2" ex, 3:23 posi/16" wheels. Two vac lines, to dist and PVC. I can crawl inside under the hood if I ever need to work on it, even if it raining.[/QUOTE]
But have you raced a Tesla yet?