Husqvarna 560: part seized?

[spudulike]

1 hour ago, richvdh said:

I guess it's possible the mixed fuel had been sitting in the can/saw for a couple of months, could that have caused the problem?

 

I think you have solved your issue yourself. Once the oil is mixed with fuel, the fuel starts degrading the oil and if left long enough, it does nothing. Two months is far too long, two weeks is OK, and two days far better. 

You should only mix fuel you will use on the day and never leave a saw on the shelf with fuel in it not knowing when you will use it next. Lots on this site stating that time and time again.

FYI...the Autotune actually does a fine job of protecting the engine. I have seen some with major air leaks survive just because the AT unit has seen the saw running lean and has increased the fuel in the fuel air mix to accommodate the extra air being drawn in to the engine.

Unfortunately, the AT won't monitor cylinder temperature so in your case with 2 month old fuel, it wouldn't have seen any issue until it went pop.

I am afraid that the dealer is probably correct in his assessment.

BTW - you are not the only one who is unaware not to mix fuel months before use!

 

[richvdh]

Yes, the red, standard, HP. And standard unleaded from a supermarket. Given the manual says max 10% ethanol, I kinda believed it...

 

I had no idea these things were so sensitive. I've had other saws which have run fine for years...

 

1 hour ago, ChrisNewport said:

2 month old fuel, id say thats your problem.

 

Sigh, it's sounding like that might be a factor. And as @pleasant says, honestly it's probably more than 2 months really. It takes me a while to get through a 5L can. Is the problem storing it mixed, or storing it at all? Would a fuel conditioner help?

[richvdh]

2 minutes ago, spudulike said:

I think you have solved your issue yourself. Once the oil is mixed with fuel, the fuel starts degrading the oil and if left long enough, it does nothing. Two months is far too long, two weeks is OK, and two days far better. 

You should only mix fuel you will use on the day and never leave a saw on the shelf with fuel in it not knowing when you will use it next. Lots on this site stating that time and time again.

FYI...the Autotune actually does a fine job of protecting the engine. I have seen some with major air leaks survive just because the AT unit has seen the saw running lean and has increased the fuel in the fuel air mix to accommodate the extra air being drawn in to the engine.

Unfortunately, the AT won't monitor cylinder temperature so in your case with 2 month old fuel, it wouldn't have seen any issue until it went pop.

I am afraid that the dealer is probably correct in his assessment.

BTW - you are not the only one who is unaware not to mix fuel months before use!

 

Well, that all seems very clear, thanks for the explanation @spudulike. Today I learnt an expensive lesson.

 

I guess now I need to figure out what to do with my saw. I can't see any point in spending 90% of a new saw in rebuilding it...

[Dan Maynard]

It'll run on 10% ethanol fuel but you have to watch the storage.

 

Some do swear by the fuel conditioner, yes. Some (me) carefully buy Esso Super which is 0 ethanol. Others buy Aspen/Motomix which is guaranteed to avoid petrol problems by not being petrol.

 

Edit: I also wouldn't run any of my kit on Stihl red, not bought Husky from a dealer but my Stihl dealer steers me away from it.

Edited January 4, 2023 by Dan Maynard

[Stubby]

1 minute ago, richvdh said:

Well, that all seems very clear, thanks for the explanation @spudulike. Today I learnt an expensive lesson.

 

I guess now I need to figure out what to do with my saw. I can't see any point in spending 90% of a new saw in rebuilding it...

I you are an infrequent user as it seems you are you would benefit from using a pre mixed alkylate fuel such as Aspen or Husqvarna X power or Stihl Moto mix .

[richvdh]

18 minutes ago, Stubby said:

I you are an infrequent user as it seems you are you would benefit from using a pre mixed alkylate fuel such as Aspen or Husqvarna X power or Stihl Moto mix .

 

Interesting. Do the premixed fuels keep ok?

[spudulike]

Fuels like Aspen, Husqvarna XP Power 2T Alkalyte and Motomix will not go off like a standard 2T oil and petrol mix will. That is why it is good for the infrequent users. 

Personally, I mix fuel up in a small lemonade bottle so I can fill the saws tank and no more. That suits my "bit of firewood", "garden pruning" or testing a saw which is my usual saw use.

Your option is to perhaps use a 1 Litre mixing bottle or use one of the previously mentioned Alkalyte fuels.

[spudulike]

42 minutes ago, richvdh said:

I guess now I need to figure out what to do with my saw. I can't see any point in spending 90% of a new saw in rebuilding it...

It is very possible that the cylinder can be salvaged and a new aftermarket (Meteor or Hyway) or an OEM piston can be fitted. It is the sort of work that made me very popular but am pretty much retired now.

A dealer may frown at this suggestion but have done hundreds of saws like it and the process works if done correctly.

[Fatboy2017]

To save yourself some money, get the saw back, post some pictures of the cylinder scoring on here, most of the time you can clean up the ally transfer off the cylinder and fit a new piston and rings, just find a local reliable saw repairer close to you to do the job, should not be too expensive. It helps if you list the area where you are.

[Stubby]

1 hour ago, richvdh said:

 

Interesting. Do the premixed fuels keep ok?

The Alkylate ones do .