Stihl 441-CMR wasted too soon! M-tronic Disassembly????

[inter_e]

Hello again guys, I haven't been on here for a while since my grandfather died. However, now I am in a fix and need some advice. My 441-CMR that I got about five years ago has given me problems ever since I bought it. Had the computer changed out under warrantee and then didn't run the saw again until new warantee was dead. Doesn't matter now as you can see from the pictures, but I have been running and working on these saws since I got my first 036 as a kid and I have never had so many problems with a professional saw. Every time the saw would get hot it would shut down with no spark like in texas or now really hot days in Missouri. Now this last time I pull it apart even though I have not used the saw enough for there to be anything funky inside and this is what I find. I am pissed, but cant seem to see how this M-tronic carb will release from my cylinder. I can see some torx but can't get to them. Never had a problem like this ripping a saw apart quickly and then throwing her back together. Could use some help for disassembly and wondering if now I should just jack my rabbit up with some mods now. Brad, are you around and I thought you used to live in Michigan like I was?

 

[Brent Nowell]

Sounds like an air leak, dirty air getting inside of the engine. The intake side is scored, poor air filter maintanence and or bad seal on the filter itself. Not starting when hot is another tell tale sign of an air leak.


The software should tell the dealers that the fuel numbers are way too high for that saw, re affirming the issue I described.

Also your crank looks really dry, another reason to run 40:1 or more for oil...

****** deal man but you def want to rebuild that if compression is low, which I’m sure it is.

Using Honda bond or some other rtv high temp sealant on the intake manifold and gaskets is a good way to make sure this does t happen again after rebuild. Loctite blue on all connecting intake machine screws as well, including head bolts.

 

[inter_e]

Thanks for all the info Brent. I took it into the dealer first and told them abot the hot issue and they said it ran fine with no codes coming up on the computer when attached . That's when I argued with them and brought it home. Everything you said makes sense except for the fact that I am religious about cleaning and changing my filter. I have always ran 50:1 in alll my saws. Are these newer M-tronic saws in need of 40:1? I can feel the score marks on my intake side which means my cylinder is fried also doesn't it?

 

[brad ruch]

I just did one not to long ago.they are a pain but that carb does slide off.have to un hook the wire connector to the carb, flip throttle rod out of the way.i also removed the black switch shaft for stop,run, choke.it slides on pretty snug.this has 2 black intake tubes instead of one like the 036.no need to remove the torqx screws except to pressure vac test.which would be the first thing I would do at this point.theres air leaking somewhere on this for sure.ill send ya a couple helpful manuals.[emoji6]

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[inter_e]

You are king, thank you tons! I kind of thought those hoses might have something to do with things like on my older saws. But all those damn wires and grounds got me spooked a bit.

 

[inter_e]

Brad and Brent thanks a lot for the knowledge, and Brad especially for reading through evrything and sending me those manuals. Man life is so much easier with those than guessing with this M-tronic setup. I have one more question if you can answer it and is there any better aftermarket kits than the stock Stihl for my cylinder, piston,etc. I dont want **** in my saw and I dont mind paying for the goods. thats why part of me thought about jacking it up now?? Any help would be great and I truely apologize for not having the time this time to search the forums because I know all my answers are there, but I have a full right shoulder replacement in a month and I need to get wood in for my family before that. My little 150TC trim saw just can't do 22" oak. Thanks Guys

 

[LegDeLimber]

The high iso is causing the pics to be awfully grainy, so tough for my bad eyes to see things.

Did the cylinder bolts feel tight and give a kind of snap or little crack when you took them out?
It shouldn't feel like they were being backed out of a wet board or just loose.
It looks like the base gasket wasn't holding on the intake side.
The cases (gasket surface) seem to have that pasty gray, mottled, look as if things have been moving.
Do you see any signs of the bolt heads pounding a dimple or burr into the cylinder flanges at the holes?

The whole saw looks to be covered in fine dust. How much attention has the chain received?
The inside kinda looks like it's been feed wood dust. Was the air filter passing fines?

 

[inter_e]

The high iso is causing the pics to be awfully grainy, so tough for my bad eyes to see things.

Did the cylinder bolts feel tight and give a kind of snap or little crack when you took them out?
It shouldn't feel like they were being backed out of a wet board or just loose.
It looks like the base gasket wasn't holding on the intake side.
The cases (gasket surface) seem to have that pasty gray, mottled, look as if things have been moving.
Do you see any signs of the bolt heads pounding a dimple or burr into the cylinder flanges at the holes?

The whole saw looks to be covered in fine dust. How much attention has the chain received?
The inside kinda looks like it's been feed wood dust. Was the air filter passing fines?

All the cylinder bolts were nice and tight. No snap or little crack but they felt torqued to around 15-20ftlbs.
Sorry about the pictures, but the cylinder is scored on both sides equally, maybe a little more on intake side, but both sides are shot.
No signs of cylinder bolts moving, dimpling or burring at the holes.

Does anyone have any advice on some aftermarket parts that are equal to OEM or better or are we still not allowed to state names like businesses on here. it's been so long since I've spent time playing on here?

 

[brad ruch]

If ya go after market go with meteor top end.

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[inter_e]

Hopefully those pictures show the damage better. IS Meteor as goood as OEM or should I just shell out the $300 friggin dollars from Stihl?

 

[brad ruch]

Yeh that's bad.totally up to you.meteor is about 140.00.first thing I would get it cleaned up.then do a pressure vacuum test.no sense putting a new top end on if there's a air leak or you will in the same boat again.and I can tell ya those cylinder gaskets are aluminum.you won't get a good seal on that I doubt it.i sure didn't I had to use some three bond to test it with on the gasket.once you bolt a new gasket down on those aluminum that's it.

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[inter_e]

Yeh that's bad.totally up to you.meteor is about 140.00.first thing I would get it cleaned up.then do a pressure vacuum test.no sense putting a new top end on if there's a air leak or you will in the same boat again.and I can tell ya those cylinder gaskets are aluminum.you won't get a good seal on that I doubt it.i sure didn't I had to use some three bond to test it with on the gasket.once you bolt a new gasket down on those aluminum that's it.

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Yeah I use that Three Bond 1194 on all my top ends. Problem is I sold all my test equipment when I left Michigan. Guess I will have to let the dealer I don't trust for **** do the pressure test for me.

 

[inter_e]

Baileys doesn't look like it has a Meteor top end for the MS441C, just the 441. The part number is 1138-020-1201 and that only matches up with the NWP set up who I have never heard of. Anyone know anything about NWP reliability?

 

[Brent Nowell]

Hey I didn’t mean to say that running 50:1 caused your problem, I just pointed out the lack of oil film on the crank. This is a hotly debated subject with many peoples opinions on the matter.
In my honest opinion, running 40:1 or even as low as 32:1 is a good thing. I myself run 32:1 on my saws for break in, and then never go higher than 40:1 for mix. More oil is a good thing for these small high rpm engines.

I know that the husqvarna autotune software will sometimes not throw a code for an air leak. It will however show fuel values for low and high jets. These numbers are interpreted by the user of the software, in which that user may see that the saw is not running normal fuel numbers. One can conclude through comparison and experience that the fuel numbers are higher or lower than normal for that model saw and that particular environment.
I think you did right to argue with the dealer that is trying to tell you nothing is wrong, clearly from the pics something is!

I also did not mean to insult you with a lack of air filter maintenance, I jumped to that conclusion with no mal intent, just the easiest answer.


You will find that the people here are very knowledgeable in most brands of saw. YouTube is another great way to watch tear down and rebuild videos.

If you can afford it, go with stihl parts for your rebuild. I really also must say that if you want this to last I would highly suggest that a positive and negative pressure test be done on the assembled upper half. This will give you piece of mind that there will be no air leak on new parts.
If this is out of your league I think it’s worth paying someone to do it. Just my two cents

 

[brad ruch]

Baileys doesn't look like it has a Meteor top end for the MS441C, just the 441. The part number is 1138-020-1201 and that only matches up with the NWP set up who I have never heard of. Anyone know anything about NWP reliability?

Top end is the same.mtronic difference is carb, flywheel,coil, clutch side case half.

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[brad ruch]

Jump on this
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/173629113847

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[inter_e]

Hey I didn’t mean to say that running 50:1 caused your problem, I just pointed out the lack of oil film on the crank. This is a hotly debated subject with many peoples opinions on the matter.
In my honest opinion, running 40:1 or even as low as 32:1 is a good thing. I myself run 32:1 on my saws for break in, and then never go higher than 40:1 for mix. More oil is a good thing for these small high rpm engines.

I know that the husqvarna autotune software will sometimes not throw a code for an air leak. It will however show fuel values for low and high jets. These numbers are interpreted by the user of the software, in which that user may see that the saw is not running normal fuel numbers. One can conclude through comparison and experience that the fuel numbers are higher or lower than normal for that model saw and that particular environment.
I think you did right to argue with the dealer that is trying to tell you nothing is wrong, clearly from the pics something is!

I also did not mean to insult you with a lack of air filter maintenance, I jumped to that conclusion with no mal intent, just the easiest answer.


You will find that the people here are very knowledgeable in most brands of saw. YouTube is another great way to watch tear down and rebuild videos.

If you can afford it, go with stihl parts for your rebuild. I really also must say that if you want this to last I would highly suggest that a positive and negative pressure test be done on the assembled upper half. This will give you piece of mind that there will be no air leak on new parts.
If this is out of your league I think it’s worth paying someone to do it. Just my two cents

You didn't insult me in any way. I knew you were just throwing me information. I also will have the pressure tests done, but I think I will go to another dealer. This one close to me I trust as far as not. That $300 plus tax is a heartbreaker, I have had good luck with Meteor before, But I never heard of that NWP. Thanks for all your help and info. It is all appreciated. Thanks, Steve

 

[Brent Nowell]

Hey np Steve. The aftermarket p&c kits are really quite good btw.

Hey you are from Michigan. You should see if you can buy the software and hardware to diagnose that saw since you have the right to repair act

That’s another can of worms in itself

 

[inter_e]

Jump on this
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/173629113847

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That is done and done. Thanks a ton for that link!

 

[inter_e]

Hey np Steve. The aftermarket p&c kits are really quite good btw.

Hey you are from Michigan. You should see if you can buy the software and hardware to diagnose that saw since you have the right to repair act

That’s another can of worms in itself

Yeah, I wonder how much that would set me back. I will look into it though and what the hell is the right to repair act? never heard of that?