Dealer says Husqvarna 550xp and 545 are junk

[blsnelling]

I think this is making sense. This system cannot adjust the mixture when the throttle plate is moving, or any time when you cannot do a lean out test. The lean out test momentarily leans the mixture and then watches what happens to the rpm, so you cannot do it if you cannot distinguish the results of the lean out from other rpm changes. Plus I don't think the tests are done often enough to respond to rapid throttle openings. So then the only strategy is to leave the mixture where it was.

However, from what I understand they are also controlling the idle rpm. I've never gotten a picture of how this is done, but the only real possibilities are by changing timing advance or mixture, and I suspect it done by mixture. But now you've linked two different things, and the mixture that gives the right idle rpm may not be right for acceleration/throttle response. Especially if the idle mixture ends up lean. If that happens when you open the throttle it will be too lean for good throttle response, although I'm assuming these carbs have an accelerator pump, but maybe the pump shot isn't enough.

If you add an opening in the throttle plate that is away from the idle fuel outlets it isn't going to pull more fuel, rather it will lean out the idle mixture as well as raising idle speed. The system will have to enrich the idle to compensate, and then when you accelerate the mixture will be at a relatively richer setting and not bog.

I could maybe imagine a similar problem if the idle mixture were set too rich for proper acceleration, but this seem less likely.

These saws have not always done this. The system is capable of working great.

 

[blsnelling]

I have been very happy with mine 550XP for one year - no problems . . !
Reed the manuel and and do exactly what it tells.
Please note the following if you are buying a new 550XP:

No manual reading is going to cure these carb problem.

 

[Chris-PA]

These saws have not always done this. The system is capable of working great.

I'm sure it is, and I would not expect every unit to behave the same way. The exact fuel mixture needed to give a certain idle speed is going vary by unit and conditions, and so will the results when you pop open the throttle at whatever mixture that ends up to be.

In general I don't like the idea of using idle fuel mixture to control idle speed, if that is what they are doing, because mixture has other effects.

 

[blsnelling]

Stihl MTronic carbs have an idle speed adjustment. It's hidden under the solenoid and not accessible.

 

[Dieseldash]

Wonder if there's a way to convert these 550's and 545's to a standard conventional carb and get rid of the electronic widgetry? My 346xp runs really sweet had it out yesterday earning its keep:

 

[Chris-PA]

Stihl MTronic carbs have an idle speed adjustment. It's hidden under the solenoid and not accessible.

I understood they were similar to the first generation AT - I don't recall reading about these types of issues on any of them?

 

[superw6]

Dealer calling Husqvarna tomorrow. Told him I would pay difference to upgrade to 550 if that's what needs to happen for good saw[emoji52].


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[superw6]

Got Uncles 545 back today for the 2nd time[emoji53]. First trip in for bog -hesitation off idle showed no errors in auto tune so they reset to default an said try again. Ran over full tank of gas and same issue as when it was new. Picked it up yesterday with new AT7 carb and can of Husqvarna pre mixed fuel(just in case). Same issue so dumped tank , installed premixed fuel and still the same[emoji35]. Screw in video was out 3/4 so tried 1/4 turn out than 1/4 turn in[emoji37]no better. Not consistent in running but to me seems like computer try's to compensate for air leak as it runs different from limbing to blocking 16" stuff. Can it have air leak but not big enough for error? I would bet money no pressure test done[emoji849]yet. Back it goes , it's 2015 model and my perfect 550xpg is 2016 [emoji856]


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4 trips to dealer and this was number 4 after " software update" to new carb installed 3rd trip. Told them twice it acted like air leak and auto tune always trying to adjust lol. 6 cookies cut from 20 log and this happens [emoji23]

 

[superw6]

the cure for hesitation , stalling was to mount bar upside down . Saw now works [emoji108]. That and putting 2016 saw on 2015 bar and chain lol


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[Finnlogger]

My colleague found a permanent solution to ALL 550 problems he had! Study these photos for the simple diy fix, all 20 tons of it...

 

[Dieseldash]

My colleague found a permanent solution to ALL 550 problems he had! Study these photos for the simple diy fix, all 20 tons of it...

Dangggggggg!

I don't think anyone has crushed a 346xp "on purpose" with a track hoe.

 

[Chris-PA]

Some people have money to piss away I guess. I would have just fixed it.

 

[TBS]

Wonder if there's a way to convert these 550's and 545's to a standard conventional carb and get rid of the electronic widgetry? My 346xp runs really sweet had it out yesterday earning its keep:

View attachment 550223

It can be done.

My colleague found a permanent solution to ALL 550 problems he had! Study these photos for the simple diy fix, all 20 tons of it...

Jeezzz

 

[TBS]

I might have to get one of these p.i.a. feedback saws and figure out a conversion.

 

[axeandwedge]

Pity to see this saw wasted like that,I had a bad experience with a secondhand MS441 I bought off an ebayer who buys broken down saws and supposedly fixes them.
After some considerable cost I rebuilt the saw ,I can't tell you what I refer to this saw as on account of the language being so bad.
At the end of the day the saw was not going to get the better of me.

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[SCHallenger]

I might have to get one of these p.i.a. feedback saws and figure out a conversion.

That just might start an interesting business for you!

 

[TBS]

I keep kicking around the idea of buying the whole system for one just to see what can be done with them.

 

[Allar]

I have a 2017 Husqvarna 545 with the hesitation off idle. It already had a carb replaced in late 2018 but now the same issue is back.
I feel like just getting rid of that turd and never ever getting another autotune saw. Really, really disappointed.

 

[Huskybill]

My colleague found a permanent solution to ALL 550 problems he had! Study these photos for the simple diy fix, all 20 tons of it...

That’s what I would do and box it up and send it to Husqvarna in Sweden to the CEO.
CEOs love to hear feed back.

 

[Huskybill]

My colleague found a permanent solution to ALL 550 problems he had! Study these photos for the simple diy fix, all 20 tons of it...

That’s one way to check the squish? Lol