Husqvarna 562XP - A Tale of Woe

[Bob95065]

I have a Husqvarna that I got not running in pieces. The piston had light scoring but the cylinder was clean. I got no other information with this saw like how this happened, how it ran, any history of problems, etc. I put a Meteor piston and a Caber ring in it and started the saw to be sure it ran. Once it started and idled a minute I immediately shut it down and took it to the dealer to get the data off the carburetor processor. They tested the fuel valve, temp sensor and throttle sensor and it passed. Then they flashed the saw and got the following information from it:


I wanted the tech to update the firmware but he talked me out of it. He said the numbers looked good and he recommended I leave it alone. In hindsight I should have insisted but I figured he knew more about these saws than I do since this was my first experience with Autotune.

Saturday I brought the 562 along with my antique roadshow saws to cut up some firewood. I ran a 20" bar on the saw for two reasons: first, I had a bar and a sharp 20" chain and second I didn't want to load the engine too much until the rings seated. It ran great and I heard a warble in the cut. when I went to idle it stopped. I started it again and cut a short time and it stopped. I went to start it and I got a sinking feeling due to low compression. I used my older saws the rest of the day.

I couldn't wait to get home to pull the muffler When I did I saw a scored piston. I went back to the hardware store/dealer for a couple of rubber stoppers for the intake so I could do a compression test. I ran into the tech who flashed my saw and an older tech that worked there. I told them what happened and we started going through causes for the failure. The older tech asked me what bar I was running and what I was cutting. I told him a 20" bar and logs up to about 16" or 18". He said that was a full bar cut that overloaded the saw before breaking it in. That didn't sound right to me because that saw can take a lot more bar than 20". Also they said running it wide open out of the cut would overheat it too. I thought that's how the computer tuned it. We agreed that I would bring the saw back after work today. I went home and did a vacuum test and the case held vacuum. I got the cylinder off and took the piston out. It's fried. What is more disappointing is the coating in the cylinder was compromised and it's not a paperweight.

Today we pulled the data off the saw and the tech said that it leaned itself out. This is what the printout said:

So comparing the two this is what I have:

In talking with him it isn't clear to me what these numbers mean. Does anyone have insight to what the saw did? Does anyone know what these numbers mean and what the scale is Husqvarna is using? I see that L went up 2 counts and H 15 counts. I don't know what this means.

If you look at the two scans above you will see that I ran that saw 7 minutes.

I had them update the firmware like I should have done the first time I went up there. This is what is shows:

So the firmware version went from 3.1.4 to 3.2.4. He said that was a big jump and should fix the problem. I noted that the numbers hadn't changed and he said they wouldn't until I started the saw. The thing is I feel like I am rolling dice here. I need to hunt down a new jug and slug and when I do I won't know if that computer will trash them in 7 minutes again or not. I think the safest thing to do would be to fix the saw, start it and let it tune then shut it down and take it back to see the tuning numbers on the printout. I read that the Duke's P/C sets are good quality, does any one have experience with them?

There's something to be said about two mixture screws and an idle adjustment screw. I like the spark advance but not the fuel mixture in Autotune.

Any help or comments are appreciated.

Bob

 

[huskihl]

I’d clean up your existing piston and cylinder enough to get some runtime on it and confirm the firmware update fixed the issue

 

[Stump Shot]

When the fuel mixture gets to the 9's, that's as much as it can adjust, or in other words it's at its maximum setting and cannot give any more fuel. Which is much the same as if an operator turned out the mixture screws to no more effect. When it was running in the 8's, that was your warning sign that an air leak was happening. It went unheeded so it did what it could, and the end result was imminent. As far as 562's go, they do not take to misuse very well and when I say this I generally mean that when ran with a dull chain heat will build up in the clutch side bearing and melt the plastic separator, which lets the balls all to go to one side and then starts tugging at the seal, which cannot hold out long and gets worse by the minute at this point. So now that the saw was kept running, both bottom and top end are blown. This of course should be confirmed by pressure/vac testing the saw and possibly a good tug on the clutch to check for movement to and fro.
This would be the death nell for most any other saw, not so for the 562. Husqvarna offers as a "fix" of sorts a inexpensive compete crankcase which when combined with a new top end kit, will put your saw back in order. Once started the autotune will quickly adjust from where it's at if a reset is not performed.
The autotune system itself works quite well, it does however and quite unfairly if I might say, get blamed for everything else bad that happens with these 5 series saws.

 

[drf256]

I love AT saws. They provide the best in performance and economy.

They‘re the best thing since sliced bread until they aren’t. Then it’s a beoch to figure out what’s wrong. The AT is a bit of a crutch because one tends not to check tune at all. I Stihl try to goose it a bit out of the cut, purely to sooth my paranoia. Stihl’s MT system seems to be a superior system vs Husky’s. I’ve seen MT compensate for loose cylinders and massive air leaks with idle and running issues, but keeping saw alive and still usable in the end.

The 562 is a great performer out of the box, but it’s maximized already in most ways. The plating on the cylinders are so thin that they generally can’t be cleaned up. I learned that the hard way also.

Anytime a saw comes to me in parts, or is already scored, it become a full case split unless I know exactly why things went wrong. It doesn’t look like you vac/pressure tested it before your initial run. I’m unsure how it held vac and pressure after the final run. Perhaps it’s what Steve said above and the massive leak is intermittent.

Are you sure you cleaned all the transfer out of the original cylinder before you ran it?

The AT just adds another level of WTF to the diagnosis when things go wrong. It’s generally not the AT system that’s at fault. Gotta go back to basics and make sure the fuel line and filter are ok, as well as the tank vent. The AT tends to make one ignore the obvious.

 

[redlight066]

I like the A/T and MTronic systems as well Steve. I have the MDG1 and Husqvarna diag. tools. I've plugged many saws in that "passed" but wouldn't run or run right. I used to perform a pressure/vac test and not cycle the engine or tweak the crank. It's a must. It's saved me a bunch of headaches in the last couple of years. There's nothing worse than "eliminating" a potential problem and move on with the diagnostic process, only to circle back.

Some of the honeymoon is over on the short block pricing, it's still a good deal in perspective of what you get. The short block is up to $229 MSRP and the cylinder kit is up to $279 for post 2013 models and $179 for the early design. Now that both Stihl and Husky have gotten parts back on the shelf, pricing has surged. I've had sticker shock a lot lately.

 

[srcarr52]

Even though it's an electronic controlled carb it can still suffer from the typical fuel delivery problems that you probably won't be clued into until it's too late. Clogged fuel filters or screens, and stiff diaphragms will cause them to lean out up top enough that the AT can no longer compensate for it.

 

[Bob95065]

When the fuel mixture gets to the 9's, that's as much as it can adjust, or in other words it's at its maximum setting and cannot give any more fuel. Which is much the same as if an operator turned out the mixture screws to no more effect. When it was running in the 8's, that was your warning sign that an air leak was happening. It went unheeded so it did what it could, and the end result was imminent. As far as 562's go, they do not take to misuse very well and when I say this I generally mean that when ran with a dull chain heat will build up in the clutch side bearing and melt the plastic separator, which lets the balls all to go to one side and then starts tugging at the seal, which cannot hold out long and gets worse by the minute at this point. So now that the saw was kept running, both bottom and top end are blown. This of course should be confirmed by pressure/vac testing the saw and possibly a good tug on the clutch to check for movement to and fro.
This would be the death nell for most any other saw, not so for the 562. Husqvarna offers as a "fix" of sorts a inexpensive compete crankcase which when combined with a new top end kit, will put your saw back in order. Once started the autotune will quickly adjust from where it's at if a reset is not performed.
The autotune system itself works quite well, it does however and quite unfairly if I might say, get blamed for everything else bad that happens with these 5 series saws.

This is very helpful. I am new to these saws and appreciate your post - thank you.

My ignorance on Autotune saws is part of the problem and the other part is I think I am working with a dealer that also doesn't understand these saws. I brought it in the first time (first data set posted above) and the numbers were L 88, H 81. You're saying this should have been a warning is something I wish I knew when I went into that shop. The tech at the dealer told me the numbers looked great and were where they should be. He gave me bad information. What is a normal range for these saws? Is that normal the same for all Autotune saws?

I've rebuilt my fair share of saws and have seen plastic bearing cages that have failed. I went through a number of Stihl 029s that had that problem. I have no history on this saw so the cage on the PTO side may have failed. I think the next step is to pull the crankshaft seals and see if the bearing cages are damaged.

I love AT saws. They provide the best in performance and economy.

They‘re the best thing since sliced bread until they aren’t. Then it’s a beoch to figure out what’s wrong. The AT is a bit of a crutch because one tends not to check tune at all. I Stihl try to goose it a bit out of the cut, purely to sooth my paranoia. Stihl’s MT system seems to be a superior system vs Husky’s. I’ve seen MT compensate for loose cylinders and massive air leaks with idle and running issues, but keeping saw alive and still usable in the end.

The 562 is a great performer out of the box, but it’s maximized already in most ways. The plating on the cylinders are so thin that they generally can’t be cleaned up. I learned that the hard way also.

Anytime a saw comes to me in parts, or is already scored, it become a full case split unless I know exactly why things went wrong. It doesn’t look like you vac/pressure tested it before your initial run. I’m unsure how it held vac and pressure after the final run. Perhaps it’s what Steve said above and the massive leak is intermittent.

Are you sure you cleaned all the transfer out of the original cylinder before you ran it?

The AT just adds another level of WTF to the diagnosis when things go wrong. It’s generally not the AT system that’s at fault. Gotta go back to basics and make sure the fuel line and filter are ok, as well as the tank vent. The AT tends to make one ignore the obvious.

The cylinder didn't have any transfer when I put it on the saw. The walls were smooth both visually and by fingernail. I made sure of that.

I learned a lot here and I appreciate your replying to my post. In hindsight I should have checked that bottom end thoroughly. I did go through the rubber components - fuel line, intake, vent, etc. I found a leaking primer at the base and replaced it. I thought I found the leak that caused the first failure but I was wrong.

 

[Stump Shot]

This is very helpful. I am new to these saws and appreciate your post - thank you.

My ignorance on Autotune saws is part of the problem and the other part is I think I am working with a dealer that also doesn't understand these saws. I brought it in the first time (first data set posted above) and the numbers were L 88, H 81. You're saying this should have been a warning is something I wish I knew when I went into that shop. The tech at the dealer told me the numbers looked great and were where they should be. He gave me bad information. What is a normal range for these saws? Is that normal the same for all Autotune saws?

I've rebuilt my fair share of saws and have seen plastic bearing cages that have failed. I went through a number of Stihl 029s that had that problem. I have no history on this saw so the cage on the PTO side may have failed. I think the next step is to pull the crankshaft seals and see if the bearing cages are damaged.


The cylinder didn't have any transfer when I put it on the saw. The walls were smooth both visually and by fingernail. I made sure of that.

I learned a lot here and I appreciate your replying to my post. In hindsight I should have checked that bottom end thoroughly. I did go through the rubber components - fuel line, intake, vent, etc. I found a leaking primer at the base and replaced it. I thought I found the leak that caused the first failure but I was wrong.

I'm not a Husqvarna trained technician. However, if in the 1's is a lean and in the 9's is rich a reasonable expectation would be somewhere in the middle.
Best advice that I can give is, it's still just a saw, forget about the autotune and diagnose just like any other saw , unless you have ruled everything else out first. This approach will "normally" get you to the problem straight away, as the majority are mechanical issues, not electronic ones.

 

[Bob95065]

I'm not a Husqvarna trained technician. However, if in the 1's is a lean and in the 9's is rich a reasonable expectation would be somewhere in the middle.
Best advice that I can give is, it's still just a saw, forget about the autotune and diagnose just like any other saw , unless you have ruled everything else out first. This approach will "normally" get you to the problem straight away, as the majority are mechanical issues, not electronic ones.

This alone helped. The tech I was working with didn't seem to understand which way was lean and which way was rich. He also was saying if the L setting was higher than H that would indicate a problem. I know how to set a 2 stroke carburetor and that didn't make sense. It would seem to me that if 1 is lean and 9 was rich you want to be somewhere in the middle just like a screw.

This is now making sense. There's an air leak somewhere in this saw. The carb was trying to compensate for it by throwing fuel at it until it maxed out. I experienced a lean seizure. The tragedy in this is the numbers in the initial data set before the seizure should have indicated a problem since the settings were L 88 and H 81. It was set close to the max setting because of a leak. I didn't have knowledge on the Autotune system and was relying on the tech who assured me these settings were normal. That wasn't the case.

A full teardown is in order. First I am going to repeat the vacuum test and move that crankshaft radially and axially along with rotating it. There's no piston on the rod so the vacuum reading shouldn't change at all. Next I'll pull the seals and look at the bearings. Finally I'll split the cases. I'm going to split the case no matter what because I want to change the bearings.

What's the best case splitter to use for these saws? I have one that looks like this:



Thank you for taking the time to reply to my posts. I really appreciate your help.

Bob

 

[farminkarman]

This alone helped. The tech I was working with didn't seem to understand which way was lean and which way was rich. He also was saying if the L setting was higher than H that would indicate a problem. I know how to set a 2 stroke carburetor and that didn't make sense. It would seem to me that if 1 is lean and 9 was rich you want to be somewhere in the middle just like a screw.

This is now making sense. There's an air leak somewhere in this saw. The carb was trying to compensate for it by throwing fuel at it until it maxed out. I experienced a lean seizure. The tragedy in this is the numbers in the initial data set before the seizure should have indicated a problem since the settings were L 88 and H 81. It was set close to the max setting because of a leak. I didn't have knowledge on the Autotune system and was relying on the tech who assured me these settings were normal. That wasn't the case.

A full teardown is in order. First I am going to repeat the vacuum test and move that crankshaft radially and axially along with rotating it. There's no piston on the rod so the vacuum reading shouldn't change at all. Next I'll pull the seals and look at the bearings. Finally I'll split the cases. I'm going to split the case no matter what because I want to change the bearings.

What's the best case splitter to use for these saws? I have one that looks like this:

View attachment 387828

Thank you for taking the time to reply to my posts. I really appreciate your help.

Bob

The splitter you have won't work for the 562 unfortunately. I would say the best splitter is the Husky shop tool ( p/n: 575286901)...kinda spendy though. If you are good at making tools, you could certainly make your own splitter and get the crank out of both case halves.

 

[Tomos770]

Next time...that should be your tool...

 

[jacob j.]

Yeah, that splitter isn't applicable for motors with crank stuffers. I've got the tool that Greg mentioned I think and I would be willing to loan it to you.

 

[big_eddy]

I understood that the number on the autotune register indicated what fraction of the time the fuel valve was CLOSED. A low number means the fuel valve is always open and flowing fuel, a high number means the valve is being closed more frequently and less fuel is allowed through .I e. Lean.

 

[J.Noss]

They said running it wide open out of the cut would overheat it too. I thought that's how the computer tuned it.

I'm not sure if you meant to say this or I misunderstood what you mean.. but running it wide open OUT of the cut is NOT how you calibrate the autotune.. it's a 5mins of low idle and then a 60sec full throttle rip-cut IN A LOG that is how the autotune is supposed to be calibrated when it's initially put together or when you first buy it, I just bought 3 different ones and my dealer made sure i understood, because apparently some people think it means a minute of full-throttle pis-revving (which it isn't) you already got some great advice here but i figured it wouldn't hurt to mention this bit.

 

[huskihl]

I'm not sure if you meant to say this or I misunderstood what you mean.. but running it wide open OUT of the cut is NOT how you calibrate the autotune.. it's a 5mins of low idle and then a 60sec full throttle rip-cut IN A LOG that is how the autotune is supposed to be calibrated when it's initially put together or when you first buy it, I just bought 3 different ones and my dealer made sure i understood, because apparently some people think it means a minute of full-throttle pis-revving (which it isn't) you already got some great advice here but i figured it wouldn't hurt to mention this bit.

Takes about 90 to 100 seconds before the autotune begins to adjust. In Walt‘s video he mentioned that they ran it wide open for 3 minutes. I noticed that at about 2 minutes it’s all done adjusting on the ones I’ve tried.

 

[J.Noss]

Takes about 90 to 100 seconds before the autotune begins to adjust. In Walt‘s video he mentioned that they ran it wide open for 3 minutes. I noticed that at about 2 minutes it’s all done adjusting on the ones I’ve tried.

It seems all the dealers have a different idea of how long it takes, my dealer suggested a 60-90sec full throttle cut for H speed initial calibration (or reset) after a 5min idle prior to that.. point I had was: some people (and indeed some dealers sadly) think that you're supposed to just Rev it full-throttle holding it *not even in a cut* for that long.. that is *not* how it's done and will destroy a new engine.. by what Bob95065 said, it had me wonder if that was possibly what was done to this saw in question.. wanted to make sure that IN A CUT bit was completely understood

 

[MarkEagleUSA]

It seems all the dealers have a different idea of how long it takes, my dealer suggested a 60-90sec full throttle cut for H speed initial calibration (or reset) after a 5min idle prior to that.. point I had was: some people (and indeed some dealers sadly) think that you're supposed to just Rev it full-throttle holding it *not even in a cut* for that long.. that is *not* how it's done and will destroy a new engine.. by what Bob95065 said, it had me wonder if that was possibly what was done to this saw in question.. wanted to make sure that IN A CUT bit was completely understood

This is from my 562XP manual (2013 model):

Engine adjustment
The following steps should be taken when the chain saw
is started for the first time or when outside circumstances
change (fuel, altitude, air filter etc.): Start the engine.
Accelerate the engine to full throttle and saw a number of
cuts in a thick log (3-5 min.).
The chain saw must be run (8,000 - 12,000 rpm) the entire
time so that the carburettor can adjust itself.
Conditions
NOTE! There is an integrated speed governor in the
ignition system that limits the maximum speed. When the
speed governor is activated, you will get the same sound
experience as when the chain saw 4-cycles.

 

[J.Noss]

This is from my 562XP manual (2013 model):

Engine adjustment
The following steps should be taken when the chain saw
is started for the first time or when outside circumstances
change (fuel, altitude, air filter etc.): Start the engine.
Accelerate the engine to full throttle and saw a number of
cuts in a thick log (3-5 min.).
The chain saw must be run (8,000 - 12,000 rpm) the entire
time so that the carburettor can adjust itself.
Conditions
NOTE! There is an integrated speed governor in the
ignition system that limits the maximum speed. When the
speed governor is activated, you will get the same sound
experience as when the chain saw 4-cycles.

Yes it seems they've changed their recommendations on that, and I see in the manuals for the 2021/2022 saws it just says what autotune is, nothing on the calibration procedure at all.
I was told that it's a 60-90sec long constant full throttle ripping cut in a log to get a cut that gives it a long enough time to make a few adjustments which you can often hear being made by the tone of the exhust note, and that is to be done immediately after letting it sit and idle for 5min. Husqvarna has a few YouTube videos explaining the procedure which they call autotune calibration / autotune reset
The important thing I was stating was that the saw should NEVER be run at WOT for 60+sec only holding it.. you MUST BE CUTTING WOOD! And if you seen what I originally quoted I was making sure that was well known

 

[MarkEagleUSA]

The important thing I was stating was that the saw should NEVER be run at WOT for 60+sec only holding it.. you MUST BE CUTTING WOOD! And if you seen what I originally quoted I was making sure that was well known

I understood what you were saying.

WOT out of the cut is already lean, or very close to it. Autotune runs the saw lean until it senses an increase in RPM and then richens the fuel. So it makes sense that extended unloaded WOT is never good (that applies to conventional carbed saws as well).

 

[Bob95065]

I'm not sure if you meant to say this or I misunderstood what you mean.. but running it wide open OUT of the cut is NOT how you calibrate the autotune.. it's a 5mins of low idle and then a 60sec full throttle rip-cut IN A LOG that is how the autotune is supposed to be calibrated when it's initially put together or when you first buy it, I just bought 3 different ones and my dealer made sure i understood, because apparently some people think it means a minute of full-throttle pis-revving (which it isn't) you already got some great advice here but i figured it wouldn't hurt to mention this bit.

I didn't explain that well. I didn't run the saw wide open with the chain in the air. I only ran it wide open when cutting logs.

Yeah, that splitter isn't applicable for motors with crank stuffers. I've got the tool that Greg mentioned I think and I would be willing to loan it to you.

This is generous of you. I want to remove the seals and look at the bearings first. I also have a home-brew splitter that I made from some angle and bar that picked up the bar nuts on a saw I split years ago. I don't remember what model it was it's been so long. I want to see if it will fit this saw.

I'm not sure when I'll get to this because I have a bunch of other projects to get out of the way this fall. The 526 will be a slow and sporadic project I'm afraid.

I understood that the number on the autotune register indicated what fraction of the time the fuel valve was CLOSED. A low number means the fuel valve is always open and flowing fuel, a high number means the valve is being closed more frequently and less fuel is allowed through .I e. Lean.

Does anyone have documentation from Husqvarna on this? The dealer i am working with seems to be confused about this too. Based on what happened to me I'm inclided to go with what I read in this thread - I had an air leak and the carburetor flowed more fuel hence the high numbers. Big Eddy's post says the opposite which would indicate the software is to blame.