MS661C 2015 M-Tronic V3 4702A Coil Calibration Now Grenaded Piston

[Iceboy]

The v3 mtronic calibration only applies to a 462. To reset the mtron on a 661, you start it in the choke position and let it run 60 seconds. Without touching the trigger, shut the saw off. Place in run position and start the saw. After idling for 60 seconds, make a few long cuts.

All M-tron V3 saws 241... 261 ..362..462..661 are calibrated the new way.

 

[angelo c]

Do you have a PN for the Stihl piston ? I've only found the entire p and c kit from Stihl OEM. Also I've had a few issues with 661s and the coil/solenoid issue, replacing the solenoid has fixed many issue for me. Black to white solenoid. The orange fuel filter is critical as well as the older solenoid seems to fail with "fines" passing through and getting to the solenoid. I have one on my bench right now that I'm suspecting has bearing failure. Fairly low hours saw too. Shame I really like this saw when it runs right.

 

[DND 9000]

The MS 661, 661 C-M piston is 1144 030 2001 (comes with 2 piston rings, piston pin and 2 piston pin clips)

 

[skygear]

Do you have a PN for the Stihl piston ? I've only found the entire p and c kit from Stihl OEM. Also I've had a few issues with 661s and the coil/solenoid issue, replacing the solenoid has fixed many issue for me. Black to white solenoid. The orange fuel filter is critical as well as the older solenoid seems to fail with "fines" passing through and getting to the solenoid. I have one on my bench right now that I'm suspecting has bearing failure. Fairly low hours saw too. Shame I really like this saw when it runs right.

FYI, this is the link I've been using to get my part number and approximate pricing.

https://www.lsengineers.co.uk/stihl-ms661-ms661c-chainsaw-spare-parts.html

Specifically this one for the piston and cylinder.

https://www.lsengineers.co.uk/cylinder-muffler-assembly-for-stihl-ms661-ms661c-chainsaws.html

 

[skygear]

I lost my links for the USA versions. If you need the repair manual/ service manual. I have a link for that too.

https://stihl.partsmartweb.com/Catdata/EMP_IMG/STGSTH/Images/SERVICE/00590458.PDF


If someone has the USA site versions of the same spare parts list links with diagrams and pricing, I'd be appreciative. I had a couple links saved that are now defunct. I like to see the pricing so I know what to expect when looking for them at the dealer or online.


The diagram and parts list is here also.

https://www.arboristsite.com/community/threads/stihl-ms661c-pars-pdf.334526/

 

[skygear]

The MS 661, 661 C-M piston is 1144 030 2001 (comes with 2 piston rings, piston pin and 2 piston pin clips)

It is recommended you replace the Needle Cage too at the same time FYI - 9512 003 3286

 

[skygear]

UPDATE: - I was not able to catch the mechanic in the shop Mon/Tues. Today I got a call around lunch time that Stihl called him and wants him to look at the saw. Bring all the parts in and he will test it. Told me he will test it tomorrow. Only took the saw, toasted Piston, Cylinder that I just sanded (said it was toast and it couldn't be used again), my old V1 parts (4700D & Black Solenoid). Take the rest of the stuff with you. No screws, \gaskets etc. that were taken off to disassemble the saw. Only testing the electronics. I'll call Stihl and you tomorrow and let you know what I find. Asked what I did. I told him the abridged version and went into calibration mode.

"Thats wrong. Thats NOT how you calibrate it!"

- But everything I have read online, all the Stihl service manuals, even videos, and forums. All claim for the V3 4702A Coil that is how it's done.

 

[stihl86]

UPDATE: - I was not able to catch the mechanic in the shop Mon/Tues. Today I got a call around lunch time that Stihl called him and wants him to look at the saw. Bring all the parts in and he will test it. Told me he will test it tomorrow. Only took the saw, toasted Piston, Cylinder that I just sanded (said it was toast and it couldn't be used again), my old V1 parts (4700D & Black Solenoid). Take the rest of the stuff with you. No screws, \gaskets etc. that were taken off to disassemble the saw. Only testing the electronics. I'll call Stihl and you tomorrow and let you know what I find. Asked what I did. I told him the abridged version and went into calibration mode.

"Thats wrong. Thats NOT how you calibrate it!"

- But everything I have read online, all the Stihl service manuals, even videos, and forums. All claim for the V3 4702A Coil that is how it's done.

What Stihl manual are you referring to. They have part numbers on the back.

 

[skygear]

What Stihl manual are you referring to. They have part numbers on the back.

https://www.arboristsite.com/commun...the-ms661-c-new-calibration-procedure.320623/



@ ~13:36




I wrote "90sec" in the op. Meant 60 sec and shouldn't take more than 90sec to complete.. That was an error on my part in typing that out as I was and am stressed that my saw is down. I did do it as the instructions and where everywhere else states though.

 

[trains]

only thing I would have done differently to you is to run the saw a bit before to warm it up, then go thru the calibration sequence.

T

 

[PogoInTheWoods]

"Thats wrong. Thats NOT how you calibrate it!"

- But everything I have read online, all the Stihl service manuals, even videos, and forums. All claim for the V3 4702A Coil that is how it's done.

That is how it's done. The mechanic is wrong. And I would highly question anything else he tells you from here on out. I'd also seriously consider using your cylinder if there are no ridges at the gouge above the port. Looks like you did an exceptional job cleaning it up otherwise.

1144-030-2001 is your OEM piston part number. MSRP is $97.55 US. A Meteor w/Caber rings is $40 and the only aftermarket piston I'd use if you decide not to go OEM.

What I'd be most concerned about before doing anything else is the condition of the bottom end. Very careful examination of the big end bearing and main bearings is essential after such a catastrophic failure to ensure no residual debris is present before everything goes back together. I've seen complete big end bearing failure in a 661C-M that was the actual cause of a similar mess. Warranty repair after sending the crank back to Herndon for analysis even after the warranty had expired. They were aware of similar failures and didn't even argue.

If the bottom end checks out and the plating is still intact on that cylinder you could be back in business for 100 bux.

 

[stihl86]

So it’s the general consensus that because the saw was calibrated differently, it led to that failure?

 

[angelo c]

So it’s the general consensus that because the saw was calibrated differently, it led to that failure?

Not a chance in hell IMO.
The two events are not related. I'd love to hear Stihls reasoning though.

 

[Fatherwheels]

Not a chance in hell IMO.
The two events are not related. I'd love to hear Stihls reasoning though.

When your saw would not start in normal mode, it would have been better to
take into the shop and read the error code, my guess would be the solenoid is
messed up, and ultimately caused the problem, but it also looks like pre detonation,
now that is usually bad fuel or timing, again, the shop might have found a code to
point to ignition module. / timing issues.

I sure understand how upsetting it is to have an expensive saw messed up,
no consolation, but I have not bought into the AT MT world yet because I
like to adjust my own carb.

I also think Stihl should do more here, you said the saw was always acting up
from new, and I would bet if the dealer addressed this initially then your saw would
be in one piece today.

I sure hope you find a resolution.

 

[Fatherwheels]

That is how it's done. The mechanic is wrong. And I would highly question anything else he tells you from here on out. I'd also seriously consider using your cylinder if there are no ridges at the gouge above the port. Looks like you did an exceptional job cleaning it up otherwise.

1144-030-2001 is your OEM piston part number. MSRP is $97.55 US. A Meteor w/Caber rings is $40 and the only aftermarket piston I'd use if you decide not to go OEM.

What I'd be most concerned about before doing anything else is the condition of the bottom end. Very careful examination of the big end bearing and main bearings is essential after such a catastrophic failure to ensure no residual debris is present before everything goes back together. I've seen complete big end bearing failure in a 661C-M that was the actual cause of a similar mess. Warranty repair after sending the crank back to Herndon for analysis even after the warranty had expired. They were aware of similar failures and didn't even argue.

If the bottom end checks out and the plating is still intact on that cylinder you could be back in business for 100 bux.

Very good advise there.
As an alternative, send it off to someone who knows how to port and build them.
It may cost, but you will have a working saw. Also check up going with a standard carb
on that saw, like this one, also post for a parts saw, with busted lower end, you will get the MT
parts cylinder and maybe piston, coil, working top end basically.

 

[skygear]

When your saw would not start in normal mode, it would have been better to
take into the shop and read the error code, my guess would be the solenoid is
messed up, and ultimately caused the problem, but it also looks like pre detonation,
now that is usually bad fuel or timing, again, the shop might have found a code to
point to ignition module. / timing issues.

I sure understand how upsetting it is to have an expensive saw messed up,
no consolation, but I have not bought into the AT MT world yet because I
like to adjust my own carb.

I also think Stihl should do more here, you said the saw was always acting up
from new, and I would bet if the dealer addressed this initially then your saw would
be in one piece today.

I sure hope you find a resolution.

I did take it in when it was on the V1 M-Tronics and asked them to help troubleshoot under warranty. Multiple times. Always got the same answer. We can't repeat it.
When she didn't start at all or idle. I again brought it in and told them.
"Now that it's out of the warranty period, we have to charge the Diagnostics fee of $XX. If we cant repeat it or have to tear it down to check things, it will cost more."
It's the solenoid. 100% It's allover the internet about it and I have been telling you the same thing sinceI got the saw and started having issues.
I'd ask about the solenoid issues I was reading about and again,
"We haven't seen anything about that from Stihl"
But here is it on all the forums people talking about similar issues
"Well, we can only go by what Stihl tells us. Plus, we can't repeat the issue"

Fast forward to getting these parts-
" I don't even have have that part number 1144 007 1809 in my system. What is it again? Oh, it's 1144 400 4703 & 0000 120 5104 & a 0000 350 3518. Huh, I wonder why it's like that. Doesn't give us much 'room'. Well, ok.. I'll put it on the next parts order. Your saws out of warranty so none of this is covered. You have to pay for it. You know that right? "
Yup. I just want to get my saw reliably working the way it should.
"We will charge the labor on it to do the out of warranty work."
I know my saws in and out. Have all the service manuals. Done a few repairs on other saws. Took small engine repair in school. Work on vehicle engines. Plus I have most of the Stihl "specialty" tools or similar non branded for working on engines. This is a simple procedure that I could do in 20min.
"Ok, I'll get it. "

-Then the call. -

It's backordered

-after the saw failure-

"The problem is you are working on your saw. Not a Stihl Certified Mechanic. "
I get it. I'm not a random just doing this to save a buck that has no clue. I'm not going to pay hundreds in labor on a simple electronics swap over. This isn't a difficult job. Small engines are not a difficult to work on. Especially well designed saws.
"Well it's out of warranty and no one will warranty the work you did. You are going to have to pay to fix it."
Let's just see if you have the Piston and cylinder kit in stock first.
" Oh, another 'kit' . Let me guess, it has all the parts bundled."
Yep.. I need the needle cage too if I'm replacing it all.

Posted on a different platform that I just grenaded after the updated parts and was told to contact Stihl anyways.

 

[skygear]

Here are the manuals. Thought they attached earlier.

If you include "https://stihl.partsmartweb.com/" in your search criteria. Lots of interesting things come up if anyone is looking for specific manuals, etc.

 

[PogoInTheWoods]

Your next order of business is to dump your dealer.

Posted on a different platform that I just grenaded after the updated parts and was told to contact Stihl anyways.

Upgrading to V.3 was not the cause of the piston failure. There was most likely already some degree of damage or uneven wear present that was simply pushed over the edge by the extended top end RPM's inherent in the V.3 calibration procedure.

That said, the damage also looks like what is referred to as a 'cold seizure'. This occurs when a cold saw is excessively revved or called upon to deliver maximum power in a cut without any warmup period..., usually with a poor quality (or ratio) of mix oil or with bad or poorly mixed fuel.

And what has been referred to as 'detonation' indicators on that piston just looks like plain old structural failure to me.

Regardless, that saw was either running excessively bad fuel for an extended period of time or had inherent problems right out of the box and was destined for failure from the get go.

Your dealer is useless and should be the last place you go for anything again..., ever.

 

[Fatherwheels]

I did take it in when it was on the V1 M-Tronics and asked them to help troubleshoot under warranty. Multiple times. Always got the same answer. We can't repeat it.
When she didn't start at all or idle. I again brought it in and told them.
"Now that it's out of the warranty period, we have to charge the Diagnostics fee of $XX. If we cant repeat it or have to tear it down to check things, it will cost more."
It's the solenoid. 100% It's allover the internet about it and I have been telling you the same thing sinceI got the saw and started having issues.
I'd ask about the solenoid issues I was reading about and again,
"We haven't seen anything about that from Stihl"
But here is it on all the forums people talking about similar issues
"Well, we can only go by what Stihl tells us. Plus, we can't repeat the issue"

Fast forward to getting these parts-
" I don't even have have that part number 1144 007 1809 in my system. What is it again? Oh, it's 1144 400 4703 & 0000 120 5104 & a 0000 350 3518. Huh, I wonder why it's like that. Doesn't give us much 'room'. Well, ok.. I'll put it on the next parts order. Your saws out of warranty so none of this is covered. You have to pay for it. You know that right? "
Yup. I just want to get my saw reliably working the way it should.
"We will charge the labor on it to do the out of warranty work."
I know my saws in and out. Have all the service manuals. Done a few repairs on other saws. Took small engine repair in school. Work on vehicle engines. Plus I have most of the Stihl "specialty" tools or similar non branded for working on engines. This is a simple procedure that I could do in 20min.
"Ok, I'll get it. "

-Then the call. -

It's backordered

-after the saw failure-

"The problem is you are working on your saw. Not a Stihl Certified Mechanic. "
I get it. I'm not a random just doing this to save a buck that has no clue. I'm not going to pay hundreds in labor on a simple electronics swap over. This isn't a difficult job. Small engines are not a difficult to work on. Especially well designed saws.
"Well it's out of warranty and no one will warranty the work you did. You are going to have to pay to fix it."
Let's just see if you have the Piston and cylinder kit in stock first.
" Oh, another 'kit' . Let me guess, it has all the parts bundled."
Yep.. I need the needle cage too if I'm replacing it all.

Posted on a different platform that I just grenaded after the updated parts and was told to contact Stihl anyways.

I agree, that’s what am saying, if Stihl had of fixed it the first time, am sure in the process
they would have discovered the problem that eventually killed the saw,
I have had similar issues with getting products looked at and sorted,
they usually look for an excuse to blame on the user first, if none is found
then they eventually have to look for the problem
I know it’s too late now, but when the dealer couldn’t find the problem you
should of contacted Stihl to take the saw back, and either find the problem
or replace the saw.
Not all dealers are the same, and that’s where the trouble lays.
I agree that there is no point in paying to change a part when you
can do it yourself, but just for your information, buy a new cylinder
and piston off Stihl, the minute you do the warranty is gone, unless
Stihl fit the cylinder and piston, might be better just buying a meteor
or cross replacement, it will be cheaper, and you will probably have
some comeback, you will have none with Stihl unless they put the parts on.

 

[Fatherwheels]

Your next order of business is to dump your dealer.



Upgrading to V.3 was not the cause of the piston failure. There was most likely already some degree of damage or uneven wear present that was simply pushed over the edge by the extended top end RPM's inherent in the V.3 calibration procedure.

That said, the damage also looks like what is referred to as a 'cold seizure'. This occurs when a cold saw is excessively revved or called upon to deliver maximum power in a cut without any warmup period..., usually with a poor quality (or ratio) of mix oil or with bad or poorly mixed fuel.

And what has been referred to as 'detonation' indicators on that piston just looks like plain old structural failure to me.

Regardless, that saw was either running excessively bad fuel for an extended period of time or had inherent problems right out of the box and was destined for failure from the get go.

Your dealer is useless and should be the last place you go for anything again..., ever.

Well said, all of it.