Husqvarna 572xp help

[r5smith]

Bought a brand new 572XP from a guy (not a dealer) to replace my old Stihl 044. Went through 2 tanks and it was running great. Then it wouldn't started while hot. Thought I flooded it trying to start it, did what I do on every Stihl I own which is starting with the throttle wide open to clear the cylinder when flooded. I was able to get it started but it was running rich, real rich and no power.

Searched online for help, pressure/vacuum tested carb and it passed. Decided only thing to do was replace the carb (auto tune carb costs $200 - make no mistake I am complaining about the cost of the carb). Decided I didn't want or need the dealer to charge me for programming the new carb so I pulled the electronics off of the old carb and put on the new carb. Started first pull and it ran like a champ. Reset the auto tone by cutting an 8' length of a log.

Pulled it out again a couple of weeks later (gas was getting old by this point). Pulled it many times and it would not start, but I could smell gas. Dumped the gas, put fresh gas in, cycled the purge bulb multiple time to try to clear the lines of the bad gad. Tried to start with throttle wide open to clear the flood. It started, same deal running rich and no power.

The only thing that seemed to be consistent before running really rich is me clearing the flooded engine by trying to start it with the throttle wide open. Just plain stupid if that can ruin a carb, but this is my first Husqvarna. Anyone experience the same problem or have advise here it is much appreciated.

 

[Andyshine77]

My guess is it was ran until the tank was empty or nearly so, the system was adding extra fuel. When you start it make a cut and it should lean on in a second or two. That or you may be missing the first pop and are flooding it. Either way try running it in a log and see what happens.

 

[r5smith]

Thanks for the reply, but when I say no power I mean it is so rich that it will barely spin the chain when free running the saw - chain brake is not on it literally has no power. It was never ran out of gas. I ran it long enough that I am reasonably sure it not the waiting for the computer to readjust anything. I have never seen this on a Stihl M-tronic saw. I have to believe this is a Husky autotune thing and was hoping someone else has experienced this and found a way to get it back to right.

 

[Andyshine77]

OK the first thing you need to do is have a dealer hook it up and test the system and reset it, a good dealer will do it for free. This video explains the exact same issue. Have you checked the metering needle? Could be stuck open.

 

[r5smith]

Andre'
That video was great and I found it the first time I had a problem with this saw. I actually called West Coast Muscle Saws when this happened the first time. The guy that made the video retired.

Even though the first carb pressure and vacuum tested fine - I replaced it but kept the original auto tune electronics to avoid the dealer charges. The electronics screw onto the side of the carb and there are 3 ports that are the interface between the electronics and the carb. Once I replaced the first carb (keeping the old electronics) it fired up first pull and ran like a champ until I needed a few weeks later and it wouldn't start.

I am thinking the pull start with the throttle wide open is really confusing the electronics. I don't know if it then does something to the carb or the electronics get fouled up to the point of no return, but given the second carb I put on the saw fired up and worked perfectly from the second it was installed leads me to believe there is something happening to the mechanic portion of the carb when you do what I did to clear a flooded engine.

I wish I could find a Husqvarna dealer around here that didn't look for every opportunity to charge me. I get it that they are in business to make money and can't be giving out their time and labor for nothing, but I am a Stihl guy and my Stihl dealers have been more plentiful and helpful.

I know a lot of people run the 572xp without issue. I see a lot of favorable information and that is why I bought it. I can't be the first person to experience this and the WC Muscle saws video tells me there are some issues with the carb. When it did run, I really like it. Low vibration and good power.

 

[czyhorse]

does it have a decomp valve? Try pulling it and putting a plug in it. I am finding that they fail a lot and produce symptoms very similar to what you are describing. Just a suggestion.

 

[Andyshine77]

Well let's see. I'd definitely check the meeting needle, if stuck open the saw will flood, but usually to the point the saw won't start period. Now if the saw has a major air leak the system is known to provide excessive fuel in an attempt to prevent engine damage. A vacuum/pressure test is definitely in order if the meeting needle isn't stuck. I would also consider eliminating the old module, could be malfunctioning intermittently. I too have swapped the modules, a few times it worked, one time it didn't and i had to have the new module programed and used that.

There is another site with some good Husqvarna dealers like Bob "aka Spike60" that may be able to help. Can't mention that site her, but it's not has to find.

Hope I've been of at least somewhat helpful.

 

[r5smith]

Thanks. Plugging the hole is a cheap and easy way to eliminate that as a cause. But I wouldn't expect it to start or run at all if you were losing air past the decomp valve. I will give that a try though.

 

[r5smith]

Well let's see. I'd definitely check the meeting needle, if stuck open the saw will flood, but usually to the point the saw won't start period. Now if the saw has a major air leak the system is known to provide excessive fuel in an attempt to prevent engine damage. A vacuum/pressure test is definitely in order if the meeting needle isn't stuck. I would also consider eliminating the old module, could be malfunctioning intermittently. I too have swapped the modules, a few times it worked, one time it didn't and i had to have the new module programed and used that.

There is another site with some good Husqvarna dealers like Bob "aka Spike60" that may be able to help. Can't mention that site her, but it's not has to find.

Hope I've been of at least somewhat helpful.

Andre',

Thanks for all of the input. I will look at the needle and do a pressure vacuum check. I have a pressure/vacuum test kit for the Stihl saws which have these really nice blanking plates that go in place of the carb. Any idea where I can pick up a blanking plate for the 572XP? Maybe Bob?

 

[Andyshine77]

Andre',

Thanks for all of the input. I will look at the needle and do a pressure vacuum check. I have a pressure/vacuum test kit for the Stihl saws which have these really nice blanking plates that go in place of the carb. Any idea where I can pick up a blanking plate for the 572XP? Maybe Bob?

Bob is not big into selling small parts much these days he's in the process of retiring the last I heard. Husqvarna makes a kit for these saws with the plates and the two metal plugs that seal the two intake boots for the strato ports. Maybe another beaker here will come along. I actually made up my own plates and plugs for the 550 and 562, I havent had to test a 572 yet.

 

[czyhorse]

You can make your own plate for the exhaust side but you will need a plate with is more of a cup for the intake side. It goes over the end of the carb boot which you can pull while the culinder is on with a lot of effort but you can’t put it back on while the cylinder is bolted down. At least that is what I found with the 372 strato which is i believe is the same as the 572 minus the auto tune on the carb. You can order the cap from a Husky parts dealer online fairly easy. You can get the part number from the service manual.

 

[Andyshine77]

You can make your own plate for the exhaust side but you will need a plate with is more of a cup for the intake side. It goes over the end of the carb boot which you can pull while the culinder is on with a lot of effort but you can’t put it back on while the cylinder is bolted down. At least that is what I found with the 372 strato which is i believe is the same as the 572 minus the auto tune on the carb. You can order the cap from a Husky parts dealer online fairly easy. You can get the part number from the service manual.

The 372 is totally different, the 572 is a completely different saw.

 

[thenne1713]

I

My guess is it was ran until the tank was empty or nearly so, the system was adding extra fuel. When you start it make a cut and it should lean on in a second or two. That or you may be missing the first pop and are flooding it. Either way try running it in a log and see what happens.

I did find I cannot start w/ both earmuffs in place, or I too flood on cold engine, but AUTO TUNE too new for me; can only say I would hope problem is operator procedure to autotune= easy resolve. BUT, did you MIX 50:1 per book/label? Proper mix w/ fresh gas should be good 24+months?

 

[SimonHS]

Try the reset procedure in this video by @afleetcommand and @spike60

Three minutes idle to set the low speed and then 45 to 60 seconds WOT under load.

 

[Andyshine77]

Try the reset procedure in this video by @afleetcommand and @spike60

Three minutes idle to set the low speed and then 45 to 60 seconds WOT under load.

That was with the old AT system, the 572 does not require such a procedure. And in my experience setting up 562's and 550's it really only takes a few quick cuts before they start acting correctly.

 

[SimonHS]

That was with the old AT system, the 572 does not require such a procedure. And in my experience setting up 562's and 550's it really only takes a few quick cuts before they start acting correctly.

572 is included in the title of the video and the video was posted in April this year, so the technique should still be relevant.

It would be great to see something formal from Husqvarna about how Autotune works, how often it samples and how to reset it without CST.

I'm not sure if @spike60 is active here at the moment, but he may know more about it, having been to the Husqvarna technical seminars.

 

[J D]

It would be great to see something formal from Husqvarna about how Autotune works, how often it samples and how to reset it without CST.

+1... I've been thinking this for a while now too

 

[Andyshine77]

Well dang it was Bob who I got the info from, maybe my noggin got it mixed up. In know with the second generation it was definitely fact, but the 572 is third generation AT and is suppose to adjust in a fraction of the time.

 

[HumBurner]

Are the newer AT generations not matched, carb and coil, like the older generations?

 

[raoul morejohn]

The brain on the carb will need to have the right program in it that matches up with the ignition. New carbs aren't sold programmed. You will need to clear the codes if using the original brain. If carb passes vac and pressure test you have an air leak or a faulty ignition.
Use a strip of inner tube on muffler side and rubber plugs on intake. I use a drilled out spark plug to apply air.
Change fuel filter I know there was a batch of bad ones. I always will swap spark plugs too...