Sick Husqvarna 550 XPG - medic required...

[Wormwood]

Dear Internet,

 

I have been the happy user of a Husqvarna 550XPG MKII for the last couple of years.

 

Summary of experience - light, powerful and responsive.

 

The saw is now playing up - periodic stalling, most frequently when cold, or when placed under high load quickly

 

Fuel used - Aspen 2-stroke (fresh)

Air filter - cleaned

Fuel filter - changed

Spark plug - looks good

 

For the last month I have tried unsuccessfully to find a mechanic capable of fixing the problem.

 

Mechanic 1 - Had the machine for 2 weeks, and then realised it was an Autotune, which was outside his comfort zone.

 

Mechanic 2 (at a Husqvarna dealer) - Had the machine for 2 weeks, said they had fixed the problem by freeing the butterfly valve. But problem persist

 

Can anyone recommend a good 2-stroke mechanic near North Yorkshire who is happy to nurse a Husqvarna Autotune saw back to racing form?

 

Best regards

 

Rod

[Muddy42]

sorry if this is obvious, but have you tried resetting the autotune?

[pleasant]

.....so is it a race tuned saw then?

[Wormwood]

4 hours ago, Muddy42 said:

sorry if this is obvious, but have you tried resetting the autotune?

Thank you for the suggestion

No, I was assuming that the repair technician would have done so if necessary.

The operators manual has the attached not very specific guidance

Based on som recent Googling I will proceed to reset the Autotune as follows

1) Run at idle for 6 minutes

2) Run at full revs under load for 1 minute (Rip cut log)

 

[Wormwood]

3 hours ago, pleasant said:

.....so is it a race tuned saw then?

Apologies for the confusion, I was speaking metaphorically.

I just need the saw to work well for normal felling operations...

[spudulike]

Probably best to plug it in to CST and see what the carb and AT are doing. Possibly a bit of crud in the gauze strainer, possibly the diaphragms need replacing. Worth changing the fuel filter and also checking the piston through the exhaust port to make sure it is clean although Aspen should have avoided and nip ups. 

Probably best to PM ADW and see if he has time to look at it. It will be a postal job but he knows his stuff.

Last thing to check are the clutch springs as if they are weak, that may be why the saw us stalling. Cleaning the air filter....must be an oil based fluid and a blast through with a compressor.

[Wormwood]

2 hours ago, spudulike said:

Probably best to plug it in to CST and see what the carb and AT are doing. Possibly a bit of crud in the gauze strainer, possibly the diaphragms need replacing. Worth changing the fuel filter and also checking the piston through the exhaust port to make sure it is clean although Aspen should have avoided and nip ups. 

Probably best to PM ADW and see if he has time to look at it. It will be a postal job but he knows his stuff.

Last thing to check are the clutch springs as if they are weak, that may be why the saw us stalling. Cleaning the air filter....must be an oil based fluid and a blast through with a compressor.

Thank you for the info, if resetting the autotune does not resolve the issue I will PM ADW...

[Wormwood]

On 21/08/2023 at 13:44, Muddy42 said:

sorry if this is obvious, but have you tried resetting the autotune?

* Update *

 

Resetting the autotune seems to have fixed the problem, thank you for the tip

[Wormwood]

*Update*

 

The problem reappeared, and the machine started consistently stalling when tilted on its side.

It turned out to be a defective fuel pickup line.

 

There was some rubber debris trapped in the fuel line, presumably a manufacturing defect because the debris looked very much like the rubber that the fuel line was made of.

 

When the saw was tilted onto its side the fuel line was held in a shape whereby the rubber debris was blocking the passage of fuel.

 

Once the debris was removed from the fuel line the saw ran fine, better then it ever had in fact :)

[Stubby]

7 hours ago, Wormwood said:

*Update*

 

The problem reappeared, and the machine started consistently stalling when tilted on its side.

It turned out to be a defective fuel pickup line.

 

There was some rubber debris trapped in the fuel line, presumably a manufacturing defect because the debris looked very much like the rubber that the fuel line was made of.

 

When the saw was tilted onto its side the fuel line was held in a shape whereby the rubber debris was blocking the passage of fuel.

 

Once the debris was removed from the fuel line the saw ran fine, better then it ever had in fact

Glad you got it fixed .