MS661 - info on new Carb, Coil & Solenoid released?

[Redbull661]

I was looking up some parts on 661 yesterday and noticed a few things on the carb, solenoid, and coil. I couldn't find any bulletins. Anyone, know more about these new releases?

carb - for the mtronic version up until now (summer 2018) it has been a WJ134A (1144 120 0610). The new carb is the WJ140A (1144 120 0612). What is the difference? Visually they look the same to me. Then I compared all the part #s side by side. The only difference in part numbers is the solenoid. WJ134 comes with a 0000 120 5110 and the WJ140A comes with a 0000 120 5104. There is a hefty price difference at least at midwest stihl. $122 old vs $212 new! (see pic) Both are available in stock as of today 8-5-18.

Solenoid - my understanding is that one of the most common problems on the mtronics 241 261 362 441 661 has been the solenoid valve (0000 120 5110). I know there has been some talk of a new "white" (old one 5110 is black) solenoid valve. In any case the new solenoid valve released is part # 0000 120 5104. As of 8/5/18 they are both listed in stock and both list out at $34.84. I can not find a news bulletin from stihl on the new one (5104).


Coil/"control unit" -

Mtronic Ver 1.0 coil/control units - 4700C 4700D (don't know the part #) - these have lower fuel values and have been associated with allowing the 661 to lean seize.

Mtronic Ver 1.5? 4700E (don't know the part #) - may still be considered Mtronic ver 1.0 - these are supposed to have higher fuel values. (I had one and it ran fine.)

Mtronic ver 2.0 - 4701A - 1144 400 4720 - these had either the same fuel values or higher than 4700E. I had 4 or 5 661s upgraded to this coil. I've run many 661s using this 4701A coil with no issues. As of 8/5/18 midwest stihl no longer sells this coil. You must purchase the 1144 400 4703 or 4704.

FYI "reset procedure" for 4700c, 4700d, 4700e, 4701a = Warm saw, bar chain on. Start saw on choke let it run choke, after 60-90sec (do not touch trigger) push switch all the way off. Restart saw now in run position, let idle (do not touch trigger), after 60-90 sec shut off. Restart saw and do 5 cuts.


Mtronic ver 3.0 coil - 1144 400 4703. I haven't seen an acutal coil in person but I would assume the shorter number on the coil itself would be "4703A". edit: it's actually "4702A" lol.

It gets better...as of yesterday 8/4/18 I noticed they now offer a newer coil yet! - 1144 400 4704.

as of 8/5/18 at midwest stihl 1144 400 4703 and 1144 400 4704 are in stock and both sell for $111.54

**********************************************

I am going to call stihl and try to find out. Unless someone here already knows?

1. is there any other differences in the 134 vs 140 carb besides the solenoid?

2. what is the difference between the old solenoid 5110 and new 5104 solenoid?

3. what is the difference between the mtronic ver 2.0 4720 coil and the new mtronic ver 3.0 4703 and 4704 coils/control units?

4. if you get a new solenoid can it be used with an old coil?

5. if you get a new coil/control unit can it be used with an old solenoid?

*********************************************

edit:

found a couple of items...

- info on the new solenoid

- info on 4703 coil mtronic ver 3.0

see attached PDF files.

 

[Stihl working Hard]

Do you have any videos on the new carb setup yet

 

[angelo c]

I was looking up some parts on 661 yesterday and noticed a few things on the carb, solenoid, and coil. I couldn't find any bulletins. Anyone, know more about these new releases?

carb - for the mtronic version up until now (summer 2018) it has been a WJ134A (1144 120 0610). The new carb is the WJ140A (1144 120 0612). What is the difference? Visually they look the same to me. Then I compared all the part #s side by side. The only difference in part numbers is the solenoid. WJ134 comes with a 0000 120 5110 and the WJ140A comes with a 0000 120 5104. There is a hefty price difference at least at midwest stihl. $122 old vs $212 new! (see pic) Both are available in stock as of today 8-5-18.

Solenoid - my understanding is that one of the most common problems on the mtronics 241 261 362 441 661 has been the solenoid valve (0000 120 5110). I know there has been some talk of a new "white" (old one 5110 is black) solenoid valve. In any case the new solenoid valve released is part # 0000 120 5104. As of 8/5/18 they are both listed in stock and both list out at $34.84. I can not find a news bulletin from stihl on the new one (5104).


Coil/"control unit" -

4700C 4700D (don't know the part #) Mtronic ver 1.0 /first gen of coil - these have lower fuel values and have been associated with allowing the 661 to lean seize.

4700E (don't know the part #) - may still be considered Mtronic ver 1.0 / first gen - these are supposed the have higher fuel values.

4701A 1144 400 4720 - Mtronic ver 2.0 / 2nd gen - these had either the same fuel values or higher than 4700E. I had 4 or 5 661s upgraded to this coil. I've run many 661s using this 4701A coil with no issues. As of 8/5/18 midwest stihl no longer sells this coil. You must purchase the 1144 400 4703 or 4704.

FYI "reset procedure" for 4700c, 4700d, 4700e, 4701a = Warm saw, bar chain on. Start saw on choke let it run choke, after 60-90sec (do not touch trigger) push switch all the way off. Restart saw now in run position, let idle (do not touch trigger), after 60-90 sec shut off. Restart saw and do 5 cuts.


Mtronic version 3.0 coil - 1144 400 4703. I haven't seen an acutal coil in person but I would assume the shorter number on the coil itself would be "4703A". It gets better...as of yesterday I noticed they now offer a newer coil yet! - 1144 400 4704.

as of 8/5/18 at midwest stihl 1144 400 4703 and 1144 400 4704 are in stock and both sell for $111.54

**********************************************

I am going to call stihl and try to find out. Unless someone here already knows?

1. is there any other differences in the 134 vs 140 carb besides the solenoid?

2. what is the difference between the old solenoid 5110 and new 5104 solenoid?

3. what is the difference between the mtronic ver 2.0 4720 coil and the new mtronic ver 3.0 4703 and 4704 coils/control units?

4. if you get a new solenoid can it be used with an old coil?

5. if you get a new coil/control unit can it be used with an old solenoid?

Julian , it's Sunday morning and it's been a half hour....what's taking you so long in downloading the timed side-by-side vids ?
Thanks in advance. Nice pickup on the carb/solenoid.

 

[DND 9000]

Anyone, know more about these new releases?

It has been mentioned in the past somewhere here:

The new (white) solenoid valve 0000 120 5104 is more dirt resistand in dusty conditions. On the old valve the sealing area was made of metal and plastic, on the new one it is completely metal. That gives a better sealing characteristic against fine dust/dirt particles.

That could also be the reason for the leaking valves and the bad running caracteristics like:

engine speed drops under load – low power,
maximum speed does not reach target value,
engine dies at idle

 

[stihlman441]

 

[blacksmith]

I didn't notice it mentioned yet maybe it was and it was just a series of number that I don't know. But as for the solenoids I was talking to my lo local Stihl dealer last week and he had just come back from a Stihl tech repair class. He told me that there is a 3rd solenoid and it is green. Now correct me if I am wrong but the black is the original the white is the 2nd version and green is the 3rd. He told me (if I remember this correctly) that if you replace a white with a black or vice versa you have to put it on the Stihl laptop and program it. But you can just replace either black or a white solenoid with a green one and no need for programming. Did I undstand this information correctly?

I have a 661 and I had the M-tronics up graded to the 4701 A coil after many trips to the shop (the saw is just over two years old). It was perfect for about 8 months then there was problems again. So frustrating that you have a saw that you can program with a laptop! I'm almost at the point that I want to set it down light the torch and melt it I to a pile of slag!

 

[FullChisel]

I am having issues with my 241 and can certainly relate to Blacksmih wanting to pull out the torch and make a nice hot pile of slag!

It worked like a champ for two years but early this Spring started getting harder and harder to start, then started dying about 6-8 times each time you did get it started before it got acclimated to the conditions.

Replaced the Solenoid, no change. Dealer had it for several days last week, he replaced the solenoid as well as the carb diaphragm, , no change. It came with the black solenoid (5110) and both replacements have also been black.

Yesterday I was working from about 7700 to 8400 feet and got into the nineties by early afternoon. It started relatively easy first thing in the morning with only about four pulls and then four more till it got warmed up and knew where it was at. Started acting up almost immediately though.

It got worse all day as the temps rose and elevation increased, frequently dying when you tried to accelerate and also dying about 35% of the time when you chop the throttle. Now quite a bit of the time it dies while idling as you are moving/clearing away brush and logs. Also REAL hard to get it to accelerate off idle without it dying. Now doing a "new" thing as well where when in a larger log at full throttle it will just die. Then 15 or twenty pulls later, if I am lucky, it will fire up again, but cannot accelerate for 3-5 minutes most times.

Also would like to ask if any of you might know which component logs the information on the use of the saw? Is it the control unit? Reason being my dealer said after he viewed the info, that the saw says it has five hours and about 600 pulls on the rope! THAT is comical. I told him I have run almost run 12.5 gallons of fuel through this saw, and I believe I am on the fourth chain and am real good at keeping them sharp and using a chain up. Basically what he is telling me is that it is not collecting or remembering the usage stats correctly. I calculate just by fuel usage I probably have over 9o hours of run time on the saw and probably pulled on that rope at least 300 times or more just yesterday.

I am going to try to get down and talk to the dealer again in the next few days to see about one of the "newer" solenoids, but figured I would see if any of you might have any other thoughts or ideas about it?

Good thing I have an old 028 AV, and an 026 as backups.....they are not near as persnickety as this new model.

Thanks in advance!

 

[DND 9000]

As I know, the newer white solenoid valve can only be used with the newer carburetors where it originally comes on. That means, if you have the older black solenoid valve, you have to replace it with the old one. See TI 45.2017 on page 3 above in this thread.

 

[blacksmith]

I am having issues with my 241 and can certainly relate to Blacksmih wanting to pull out the torch and make a nice hot pile of slag.

Good thing I have an old 028 AV, and an 026 as backups.....they are not near as persnickety as this new model.

Thanks in advance!

I know what you mean about having a good reliable saw. I have an 026 as well that when we were topping out a tree a 10" butt of a 20 ft top from about 30 ft up that we dropped hit my 026 squarely on top of the cylinder then smashed the rear handle and tank! Pulled on the cord just to see if the engine would turn hoping that the piston and cylinder wasn't trashed and locked up from being crushed. Guess what it fired up and ran till the gas ran out of the carb!

Dallas hooked me up with a new rear handle and some other parts. Put it back together never had to retune it and I still use it today!

Here's some pictures of the carnage.

 

[FullChisel]

Oh MAN!.....If that were to happen to one of my older saws I think I would just break down and cry right there!

But if it happened to this newer one, it might be an improvement!

 

[FullChisel]

So I waited till the temperature got up to 95 here today and just came in from trying it out again. Here the elevation is right around 5200 feet.

It started up on the second pull but required two more starts to get it to idle for a couple minutes.

It ran fine, crisp off idle, did not die once upon throttle chop, and restarted almost flawlessly with just one pull. It still and always has great power. I switched it off several times while cutting with it just to try restarts and no issues at all, came back to life each time with only one pull. I let it sit as I cleaned up and stacked the wood I cut and upon restart, maybe ten minutes later it did have a little hesitation off idle several times and twice did die when the throttle was hit, but nothing near as bad as when at altitude in the mountains.

Have any of you heard of any issues with these m-tronic carbs at higher altitude?

I know my dealer cannot duplicate these issues as they are now looking to be elevation caused, but I am also sure I cannot be the only one having these kind of problems.

 

[Redbull661]

Ordered the new "white" solenoid 0000 120 5104.

Here it is side by side with the first gen black 0000 120 5110.

Notice on the instructions there is a 0000 120 5111. Wonder if that might be the new "green" solenoid which from the above post by @blacksmith sounds like it will work in both carbs wj134 and wj140.

 

[Redbull661]

Also ordered a mtronic ver 3.0 , 1144 400 4704 coil.

It has the same 4702A as the 1144 400 4703 version 3.0 coil.

So don't know why they would both have 4702A on them unless it's just a parts number change?

I will of course "have to" heh run both coils for time and see if there is an advantage to either.

 

[FullChisel]

So the issues continue. Dealer is being REAL good about working with me, even has another dealer from up in Colorado trying to help out as well. They are just as perplexed as I am though.

Waiting on both a new carb and a new control unit as not sure which might be the culprit. I am thinking it is control unit as now have been through the carb twice, dealer went through it once as well. Seems carb related but I have seen some coils act up when real hot as well over the years so unsure at this point.

This last time I took it down as close as possible to the casting and then examined it real in depth under a microscope. The ONLY thing I cannot look through or at due to how it is mounted is the little shiny pressed in piece that sticks up maybe a quarter inch into the main air intake on the carb. It is located right where the solenoid pushes the gas into the throat of the carb. I saw in one forum where they refer to it as a compensator valve? It looks like it might be some sort of a one way check valve? Anybody have any experience or knowledge with these? Stihl is not saying anything about this component.

That also seems to be the ONLY part I could see that would require a full replacement of the carb, as everything else is pretty simple, straightforward, and can be looked through or examined.

After I went through it I again, it works fine at 5200 feet, so I took it back up to altitude and although a little better it still has issues coming up off idle. It NEEDS a low speed adjustment! It does appear to be getting a little better but that could well be because the temps are starting to come down, especially up higher in the hills. I am also getting a little better/quicker at feathering the throttle application to keep it running till it can gain some rpm. Once it gets a few hundred rpm up off idle it runs as good as ever, although it will still occasionally die upon throttle chop.

Am curious to see if it does clear up completely as the temps continue to drop? May find out if the replacement parts do not get here soon! If they do not arrive I may have to continue the issue hunt next year once the temps start to rise again?

 

[FullChisel]

Oh yeah, I did talk to the dealer and he said none of the newer solenoids will fit this saw. I guess those only fit the 441's and 661's?

 

[Redfin]

Ordered the new "white" solenoid 0000 120 5104.

Here it is side by side with the first gen black 0000 120 5110.

Notice on the instructions there is a 0000 120 5111. Wonder if that might be the new "green" solenoid which from the above post by @blacksmith sounds like it will work in both carbs wj134 and wj140.

Interesting they added another O-ring. I have speculated the trouble with some of these solenoids is just a poor seal to carb body.

 

[blacksmith]

I have some update about these elusive green solenoids. I was talking to my local Stihl dealer and he said the there are green solenoids but Stihl is only releasing them once all of the black ones are used up from the stock.

He said that if there are solenoid problems it will be replaced with the black ones that are in stock. Even if your saw is out of warranty and if it is replaced with a black one Stihl will honor that as a warranty issue if it ever needs changed again and will continually be replaced if needed. And you will eventually end up with a green one!

 

[RI Chevy]

That kinda sucks.

 

[FullChisel]

I wondered after seeing you guys talk about the white and then the green ones if that might be the case.

I first bought one (this was before I discovered this site) and they sold me a black replacement. Then after the dealer worked on my saw and replaced that one with another black one, and then when I asked him about the white and green ones he said the white ones would not fit my 241 saw and new NOTHING about any green ones. Now I think they are just trying to use up old existing stock, but from what I am seeing they might all be garbage, so why not admit that and issue new problem free (I hope!) replacements?

After I replaced my first one I did take apart and go through the original. It was clean as a whistle and I did not see any issues. I put it back together and it works but still has the acceleration issues.

They are working with me and warranting these but if they are a known issue you would think they would want you happy and it would make less work for everyone involved? But what do I know?

 

[blacksmith]

I wondered after seeing you guys talk about the white and then the green ones if that might be the case.

I first bought one (this was before I discovered this site) and they sold me a black replacement. Then after the dealer worked on my saw and replaced that one with another black one, and then when I asked him about the white and green ones he said the white ones would not fit my 241 saw and new NOTHING about any green ones. Now I think they are just trying to use up old existing stock, but from what I am seeing they might all be garbage, so why not admit that and issue new problem free (I hope!) replacements?

After I replaced my first one I did take apart and go through the original. It was clean as a whistle and I did not see any issues. I put it back together and it works but still has the acceleration issues.

They are working with me and warranting these but if they are a known issue you would think they would want you happy and it would make less work for everyone involved? But what do I know?

I am not sure about the solenoids for the 241's. The color of the different solenoids that I was referring to was for the 661's being that I have one and that was the issues that I was dealing with. Mybe they do have the other white and green ones for the other saws I am not sure.