261 M-Tronic - What makes it tick.....

[Greenerpastures]

Many say with saws offered in both MT and regular carb/ignition that outright performance favour the non MT units that can be manually adjusted (leaned out) to the ragged edge for more power/speed (rpm). Just thinking 'if' you could change the MT system what would you change for increased performance etc.

Hi CR888
Exactly what am talking about regarding MT and AT, we should all be standing back in amazement at the difference in power between an AT or MT
saw, bur we are not, so why, the controller is obviousley being fed information, they obviousley have pre programmed paramiters to work
within, so why not give more scope and program these paramiters to
do the task better, that is all it would take.

 

[Greenerpastures]

True but you have to consider the facts.
The auto industry (or motorcycle for that mater) does not have the constraints the saws do. Such as Temp (their ECU is in the cab), extreme dirt and dust, normal gas verses a mixed fuel.


To start with would be the timing aspect.
Being able to adjust the saw (depending on the chain mounted) for RPM or torque....
In some instances you might want a lot of RPM.
In others torque might be advisable to get thru that large hardwood... Again, that would be for the tuner / owner / operator to decide.

Hi breese
I undersand, but it is their disigners that put the likes of theECU where it is,
did Boeing put their flight controller in their fuel tank or anwhere stupid, no.
They need engineers and designers that can do better.
And yes, I fully agree, the charachteristics of a saw need to be adjustable
so the end user is happy, either low down torque, or speed for repetative duty tasks, and all this is possible, tell the microcontroller what mode or mood you are in and that shoud be it.
Too many men in suits, fancy advertising and lack of real skill is why it has taken so long to
get the small distance they have.

 

[MustangMike]

1) The upcoming MS500i will be fuel injected (80 cc).

2) Most of the M Tron saws no longer have a key, it is built into the flywheel. Makes it more difficult to modify, and costly to replace.

3) I remember several reports of the initial 441 M Tron saws running stronger than their manual adjusted counterparts (in stock form).

Modding the timing on a M Tonic saw does (sometimes) make it run stronger. Some builders that did not do it at first do it now.

 

[Greenerpastures]

1) The upcoming MS500i will be fuel injected (80 cc).

2) Most of the M Tron saws no longer have a key, it is built into the flywheel. Makes it more difficult to modify, and costly to replace.

3) I remember several reports of the initial 441 M Tron saws running stronger than their manual adjusted counterparts (in stock form).

Modding the timing on a M Tonic saw does (sometimes) make it run stronger. Some builders that did not do it at first do it now.

Real glad to hear the reports of MT amounting to a stronger running saw,
it always should have been so, for a carb once set has no brain to optomise it, where a chip controlled saw should have.

You mention fuel injection, that should explain where the top
techs have been, and may be also explain why not enough effort was
put into making MT better.

That was not nice of them to incorporate the key into the fly wheel,
no dout it costs a lot more to machine the center of that wheel,
and what for, to keep people from bettering their saws.

 

[backhoelover]

The MS 362 gets M-Tronic Vers. 2 soon.
They released a technical information for the dealers.
New cylinders/Coils and carb to get this saw more robust.
They have new Solenoids for dusty enviroments.

i was talking to stihl tech thursday. we are behind 2 years on tb for some models. did that come from stihl germany?

 

[backhoelover]

@breese. now we need to get you a ts500i stuff so you can shine some like on it lol. @alexcagle did tear a injector down. he is the world leading expert for concrete saws!!!!!!!

 

[backhoelover]

http://www.arboristsite.com/community/threads/so-i-took-a-stihl-ts500i-injector-apart.307486/

 

[FergusonTO35]

As far as I can tell, this technology is similar to the feedback carburetors on cars of the late 70's and 80's. Not much different than previous products except semi-computerized fuel control and spark, which of course gives easier starting (usually) and better smog control.

 

[breese]

As far as I can tell, this technology is similar to the feedback carburetors on cars of the late 70's and 80's. Not much different than previous products except semi-computerized fuel control and spark, which of course gives easier starting (usually) and better smog control.

There is No Feedback from anything external to the Coil pack.
The carb solenoid does not report anything that we can tell at this point.

Edit: it is possible the solenoid is reporting current position but cannot confirm that at the mooment

 

[Greenerpastures]

What sensors are on this saw, knowing this will narrow
down what is going on.

 

[breese]

While the software has information on a number of saws, the only ones I can confirm at the moment is a Temp sensor and the RPM sensor.
The temp is embedded within the coil pack and I think it is reading the temp of one of the coils. My guess would be the secondary coil (High voltage for spark plug) but it is possible there is something more happening I am missing...
The RPM is the same for all Electronic Ignitions in saws.. Its the second pickup on the coil reading the TDC sensor on the flywheel... Difference with the M-Tronic is they are using this info for possible fuel rate to use...

Currently into the beginning stages of analyzing the software....

 

[FergusonTO35]

Didn't know that, I thought the ignition was in the mix as well. Alot of early EFI cars had transistor or microprocessor controlled ignition which operated independently of the main ECM, although it usually fed an RPM and crank position signal to the latter.

 

[breese]

While I have not located a method of the built in CPU to actually fire the secondary coil, it is still possible there is a way they are releasing the Capacitance charge (normal operation of the electronic ignition) thru some type of transistor.

I will say there is a lot more to this 30 pin CPU and all the traces coming off of it then I would have expected.

If you look at the flywheel you will see the magnet/s and the sensor to indicate TDC and that is what tells the coil to fire.
The M-tronic gives the added ability to monitor TDC and make adjustments as they want.

 

[Greenerpastures]

If the magnet triggered the spark at TDC, it would be pointless
as the party would be over, monitoring the TDC location would
not even allow a cpu based system to fire in time, unless you
programmed it to do a countdown in reverse, a complete waste
or processing, a signal 35 deg BTDC would allow the system
time to respond calculate and fire. But none of this matters as
Stihl would seem to be developing a fuel injection system.

Why invest time in figuring out what Stihl will be dumping
for a newer tech, the same time could be spent developing ones own
fuel system and selling it on, the components are out there, its only
a matter of wanting to design such. Would be nice to beat them at their
own game, but at what cost, Stihl will come out on top, they will undoubtidly keep their code a secret, and hide the chip and sensors so no one can get to grips with what they are doing.
At most, one will be able to interfear with their design in order to trick it,
but getting to the bottom of something so well hidden is one reason I use a carb,
I wish you all good luck in your pursuit,
and when you are at it, falling for this tech will result in the abolition of
the carb, think about the impact that will have, all of us tied into the Stihl
way of life, and severily impacted port jobs.
I won't be helping Stihl or Husqvarna hammer me in the future, no thanks,
I don't live in a box, there is a bigger picture, saws that burn out because the user
has no control over how they run, wonder who that will bennefit.

 

[breese]

Greenerpastures,
Thank you for your opinions....
I know for fact how the coil is triggered. As for investing time... It is mine and what the end result might be.
The thread was started as an information thread and has grown the attention of a lot of saw people including yourself it seems...
As we move forward in discovering the methods used, decisions can then be made to what to do or not do with it.
Either way, weather the information gained is used to help with this product, create something new, or as a stepping stone to whatever comes out in the future, only time will tell.

 

[nohoff]

i was talking to stihl tech thursday. we are behind 2 years on tb for some models. did that come from stihl germany?

This document is from Stihl Germany.

 

[Greenerpastures]

Greenerpastures,
Thank you for your opinions....
I know for fact how the coil is triggered. As for investing time... It is mine and what the end result might be.
The thread was started as an information thread and has grown the attention of a lot of saw people including yourself it seems...
As we move forward in discovering the methods used, decisions can then be made to what to do or not do with it.
Either way, weather the information gained is used to help with this product, create something new, or as a stepping stone to whatever comes out in the future, only time will tell.

I agree, but I just don't trust that the future should be dictated by
accepting the tech that Stihl and Husqvarna are putting in these saws,
as you have found out, it is well enough hidden, but worse is to come,
my impression is that that saw manufacturers will use the EPA as a way
to impose completely closed tech on us, it will eventuall be deemed neccessary to lock down the saws, and their very design will make it financially and physically impossible to come up with a work around,
I see what is happening now as the first round of whats to come.
That is why I want to see the carb stick around, for when its gone, saws will be
very expensive and all those who are now looking forward to the next must have
piece of tech from Stihl and Husqvarna, will be wondering why they did not see what is coming.

 

[nohoff]

Or it is our chance to look at this m-tronic and injection and open this for everyone.
If we reverse engineer the software we can do a open source Stihl Diagnostic System.

 

[Greenerpastures]

Or it is our chance to look at this m-tronic and injection and open this for everyone.
If we reverse engineer the software we can do a open source Stihl Diagnostic System.

We can indeed, but when stihl dumps the hardware for their next must have piece of tech, nothing will have been gained.
I think we are heading for a locked down saw platform, to please the EPA
and make more money for Stihl and Husqvarna, and I can't help them along
by buying such products or promoting them.
The only thing that will stop or slow them down is poor sales of such saws.

Try modding a saw that is not adjustable, regarding fuel or timing.
Look at their new flywheel that has the key built into it, tripling
the cost for anyone who wants to change the timing, nice feature indeed.
And when injectos come along, look at the cost then of trying to mod,
will be almost impossible to add a carb, aftermrket P&C s will be reauired
with ports that the new tech dont use, as will flywheels with magnets
and old style ingniton units,
by the time the mod is complete the bill be a heavy one.

 

[breese]

We can indeed, but when stihl dumps the hardware for their next must have piece of tech, nothing will have been gained.

If you don't mind, I would like to keep this thread as an information thread on what we are finding and the possible things we can do with it.

While I understand your thoughts and concerns, I would feel better if you were to start another thread. I / we are doing our best to help those that want information on how This Is Working and what we are finding along with the possibility's it can be used for.

Thank you.