Brand new 550xp stumbles & dies after idling for few seconds between cuts. What the..??

[rustyb]

I have less than 15 minutes run time on a brand spanking new 550xp. Bone stock and untouched except me putting a Husky felt filter on it.

It runs awesome during limbing and bucking the ~6" stuff I've cut thus far. HOWEVER, when I sit the saw down to move a piece of wood....or even let it idle for ~3 seconds between cuts...it stumbles when I give it gas again and then dies. It then takes 3 pulls to get it restarted then runs ratty for a second or two before cleaning up with high RPMs.

All this happens every time it idles for just ~2-4 seconds.

Am I missing some special "auto tune" tune-in method upon a cold start-up? Or is there something already wrong?

FWIW, I'm running full synthetic Stihl oil at 50:1 with 91 octane.

 

[CBeal34]

I don't think you're missing anything. They have an issue and the dealers so far have no idea. Too bad because it's a great saw when right.

http://www.arboristsite.com/community/threads/550xp-stalls.294629/

http://www.arboristsite.com/communi...-hard-to-start-and-hesitates-off-idle.213285/

 

[Chainsaw Jim]

Are you using fuel with ethanol in it?
Also..Husqvarna oil is higher quality than Stihl oil and some Husqvarna dealers will void your warranty if they catch you using it.

 

[rustyb]

Holy crap! Had I known this was such a wide spread issue........

I purchased the saw from Bailey's. I don't want to have to go through the process of the saw being shipped back and forth.

There are a few dealers around here....but none that carry the XP models. They all have the homeowner Huskys.

One thing I did notice is that there's some black stuff being blown out of the decomp valve (I see it on the underside of the plastic cover). Loose, perhaps? Could this be the problem?

 

[rustyb]

I just went out and tried the saw again...hoping the issue would magically go away. Same issue. I also notice that it runs ratty, or way rich, for a while before cleaning up, even if it doesn't stall. Then it runs really good...then goes back to running ratty. At one point, I even smelled gas.

I have never been a fan of new fangled technology with all its great promises...on any thing. To me, these complexities just mean more things to go wrong and more clutter while trying to work on whatever it is. This time though, I decided to ignore those feelings. After all, I figured if there were any issues, the factory would have them worked out by now. It appears now that ignoring my own beliefs has bit me in the butt.

I tell ya, I am seriously bummed.....

 

[rustyb]

No ethanol, Jim. Wouldn't think that would matter anyway. After all, this carb is supposed to self-adjust for everything...or at least that's what I thought.

 

[zogger]

If it is a later model it should have the updated carb. There's a calibration sequence you need to do, what it is exactly I forget, just read about it here. It is in your manual I believe.

 

[Chainsaw Jim]

This is exactly why Stihl will not allow online sales. Problems or out of tune saws are quickly blamed on the quality of the product because people assume they're ready to go out of the box.

 

[CR888]

I'd firstly check your decomp is secure and tight, perhaps swap it out with a known good one. Secondly read the owners manual and follow new saw proceedure to set the AT system. Next if you still have same issue stop running the saws and remove external transfer port cap and check that the Oring gasket has been installed correctly and is doing its job (many come from the factory poorly installed). Check compression if you have a gauge. If these basic health checks don't find the problem you must use the warranty you paid for when buying the saw. This does not neccesarily mean you need to ship the saw to baileys, I believe warranty work can be assessed by any authorised Husky dealer. Maybe a sponser here could offer to check your saw. Persist with it as when they run as they should they are the best 50cc saw on the market period. I say this and am not a big husky fan. I'd also use a good quality mineral oil for break in period not synthetic, but oil is not your problem at the moment.

 

[sambruin7]

My new 550xp was running like that also and turns out the decomp valve wasn't on tight enough. Mine runs awesome now.

 

[blsnelling]

I suspect you have a bad carb.

 

[rustyb]

Next if you still have same issue stop running the saws and remove external transfer port cap and check that the Oring gasket has been installed correctly and is doing its job (many come from the factory poorly installed).

Thanks. Can you or someone else tell me what and where the "external transfer port cap" is?

 

[rburg]

An auto tune saw isn't tuned by a dealer before it is sold and I don't believe a m tronic model is either.

 

[Philip Wheelock]

When these saws have idling issues, it seems like it's always the carburetor; there's no guaranty that the saw you got from Bailey's has the latest carb. There has to be a local dealer near you that services the pro's who can diagnose the problem and replace the carb as necessary; otherwise there are a couple of AS dealers who I would trust to do the same.

 

[sambruin7]

Mine started acting up again today. I thought it was the decomp valve but wasn't it. Hard to start, shuts off at idle sometimes, and the compression is really low. The pull rope has almost no resistance even though I didn't press the decomp valve. I'm beginning to think mine has a piston and ring issue.

 

[Chainsaw Jim]

An auto tune saw isn't tuned by a dealer before it is sold and I don't believe a m tronic model is either.

They gas and oil all saws and run them to make sure they are running correctly. Auto tune is programmed from the factory, but still needs test ran at time of sale to assure proper running. Non autotune models are factory preset and are fine tuned at time of sale when test running.
This one would have never made it out the door.

 

[Landmark]

Man glad i read this before i bought a 550. I guess i will wait till they get this issue fixed. I think i would ship it back to baileys and see if they would fix/replace or refund. Not sure what their policies are for saws. Also if you order a saw it should be ready to run straight out of the box. Especially a AT or mtronic saw since 99% of us cannot reprogram or retune them. I think i will stick with my 262 for a while longer. The hda87 carb has it purring like a kitten.

 

[CBeal34]

In my case, the saws were started by the dealer, fast idled for 30 seconds or so & then raced up a few times then out the door I went. Total run time was 2 minutes max. Unless the saw was put in wood for 5 - 7 minutes the symptoms would not show up. All three of mine ran cold like any saw does & also my 562xp. They were plugged into the Husky software & no codes were shown other than the short run times & excessive starting. I do not know what the dealer did when he had them but I did see him adjust the flywheel to coil gap (what he called it) & we tried the magic air bypass on the 3rd one. He hadn't heard of it & it had no affect. Saws had the Husky pre-mix for fuel. This issue has two local dealers stumped or thinking I'm nuts, not sure which.

 

[rustyb]

Unless the saw was put in wood for 5 - 7 minutes the symptoms would not show up.

And that's exactly what happened in my case: The issue didn't show up in the first few minutes of sawing. In fact, it ran awesome the first time I ran it which only amounted to several cuts in smallish wood. It ran well the second time I ran it too. Same conditions and run time.

I just hope one of the dealers here has a mechanic that is both sharp and amenable to deal with. And I really hope a simple one-time visit will get this saw running properly....for a long time! Cause I just sold and shipped my low-mileage, great running, and simple to work on 346xp NE. Man.....hope I don't regret that!

 

[Chainsaw Jim]

It can take a good 3 or 4 minutes at wide open throttle in wood before these autotune saws reset and tune.
I'd find some larger wood to make some long cuts.